Northborough, Massachusetts

Dear Aspen Aerogels, Inc. Stockholder:

You are cordially invited to attend the 2023 annual meeting of stockholders of Aspen Aerogels, Inc. to be held at 9:00 a.m. Eastern Time on Thursday, June 1, 2023. This year’s annual meeting will be conducted solely via live audio webcast on the Internet.

You will be able to attend our annual meeting, vote and submit your questions during the annual meeting by visiting www.virtualshareholdermeeting.com/ASPN2023. You will not be able to attend the annual meeting in person.

Details regarding the meeting, the business to be conducted at the meeting, and information about Aspen Aerogels that you should consider when you vote your shares are described in the accompanying proxy statement.

At the 2023 annual meeting, two persons will be elected to our board of directors. In addition, we ask stockholders to approve two amendments to our Restated Certificate of Incorporation, approve the Aspen Aerogels 2023 Equity Incentive Plan, ratify the appointment of KPMG LLP as our independent registered public accounting firm for our fiscal year ending December 31, 2023, and to approve, on an advisory basis, the compensation of the named executive officers, as disclosed in our Proxy Statement for the 2023 Annual Meeting. Our board of directors recommends the election of the two nominees to our board of directors and a vote in favor of proposals (2), (3), (4), (5) and (6). Such other business will be transacted as may properly come before the annual meeting.

We hope you will be able to attend the annual meeting. Whether you plan to attend the annual meeting or not, it is important that you cast your vote either virtually at the time of the annual meeting or by proxy. You may vote over the Internet as well as by telephone or by mail. When you have finished reading the proxy statement, you are urged to vote in accordance with the instructions set forth in the proxy statement. We encourage you to vote by proxy so that your shares will be represented and voted at the meeting, whether or not you can attend.

Thank you for your continued support of Aspen Aerogels, Inc. We look forward to seeing you at the annual meeting.

Aspen Aerogels, Inc.

30 Forbes Road, Building B

Northborough, MA 01532

NOTICE OF 2023 ANNUAL MEETING OF STOCKHOLDERS

TIME: 9:00 a.m. Eastern Time

DATE: June 1, 2023

ACCESS: www.virtualshareholdermeeting.com/ASPN2023

This year’s annual meeting will be a virtual meeting via live webcast on the Internet. You will be able to attend the annual meeting, vote and submit your questions during the meeting by visiting www.virtualshareholdermeeting.com/ASPN2023 and providing relevant information, including the control number included in the Notice of Internet Availability or the proxy card that you receive. For further information, please see the Questions and Answers about the Meeting beginning on page 1.

PURPOSES:

WHO MAY VOTE:

You may vote if you were the record owner of Aspen Aerogels, Inc.’s common stock at the close of business on April 4, 2023 (the “Record Date”). A list of registered stockholders as of the close of business on the Record Date will be available at our corporate headquarters for examination by any stockholder for any purpose germane to the Annual Meeting for a period of at least 10 days prior to the Annual Meeting. If you wish to view this list, please contact our Corporate Secretary at Aspen Aerogels, Inc., 30 Forbes Road, Building B, Northborough, Massachusetts 01532. Such list will also be available for examination by the stockholders during the Annual Meeting at www.virtualshareholdermeeting.com/ASPN2023.

All stockholders are cordially invited to attend the annual meeting. Whether you plan to attend the annual meeting or not, we urge you to vote by following the instructions in the Notice of Internet Availability of Proxy Materials that you previously received and submit your proxy by the Internet, telephone or mail in order to ensure the presence of a quorum. You may change or revoke your proxy at any time before it is voted at the meeting.

Northborough, Massachusetts

CREATING VALUE THROUGH TECHNOLOGY AND INNOVATION

Dear Stakeholders,

Our business continues to accelerate, with increasing market adoption of our high-performance thermal solutions fueling a strong performance in 2022. Our Energy Industrial business with value drivers of efficiency, resiliency and safety had an outstanding year. Overall, we delivered record annual revenues of $180.4 million, an increase of 48 percent year-over-year, and achieved record PyroThin^® thermal barrier revenues of $55.6 million for the year, an increase of nearly 9-times as compared to 2021 revenues. These results represent the continuation of a multi-year strategy to make our business a profitable growth engine. We remain dedicated to delivering a positive cycle of mutual benefit to our customers, suppliers and partners.

Aspen is built on innovation. We are a leader in proprietary engineered materials designed to improve the performance and safety of electric vehicles and energy industrial assets. We are working with a heightened sense of urgency to create lasting value for our stakeholders by helping industries – and society as a whole – solve some of the world’s most pressing technological challenges.

2022 Highlights and Recent Business Developments:

2022 was a transformational year for Aspen. The significant adoption of our PyroThin^® thermal barriers in the electric vehicle (EV) market, along with an improving energy infrastructure market, has propelled our company forward in significant ways.

Aspen is setting a new standard for energy efficiency, asset protection, and fire safety in both traditional and new energy sectors, and our commitment to continuous innovation is leading the way to a more sustainable future. We believe in the power of diversity and inclusion at every level of our organization. For the past two decades, sustainability has been linked to the success of our business; and it is a natural fit for us to explore new uses for our Aerogel Technology Platform with the goal of improving the environmental performance and safety of our customers’ products and processes. In 2022 we published our inaugural ESG Highlights Report and launched an ESG webpage, which provide a comprehensive overview of our overall ESG strategy. In addition, we were awarded a silver medal by EcoVadis, an independent rating agency that rates suppliers based on their environmental, social and financial performance. These awards are a confirmation of our approach and a motivation to continue with our efforts.

We are positioned to build on our momentum in current markets and to explore new markets that are aligned with our strategy and support continued robust growth. The entire management team and I extend our sincere appreciation for your continued trust, confidence, and support. We remain committed to maintaining the highest ethical standards in our relationships with all our stakeholders, and to exceeding your expectations at every opportunity. I look forward to continuing to collaborate with you in the years ahead.

Sincerely     Donald R. Young   President & Chief Executive Officer

TABLE OF CONTENTS

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Aspen Aerogels, Inc.

30 Forbes Road, Building B

Northborough, Massachusetts 01532

PROXY STATEMENT FOR THE ASPEN AEROGELS, INC.

2023 ANNUAL MEETING OF STOCKHOLDERS TO BE HELD ON JUNE 1, 2023

This proxy statement, along with the accompanying notice of 2023 annual meeting of stockholders, contains information about the 2023 annual meeting of stockholders of Aspen Aerogels, Inc., including any adjournments or postponements of the annual meeting. We are holding the annual meeting at 9:00 a.m. Eastern Time on Thursday, June 1, 2023. This year’s annual meeting will be conducted solely via live audio webcast on the Internet. You will be able to attend our annual meeting, vote and submit your questions during the annual meeting by visiting www.virtualshareholdermeeting.com/ASPN2023. You will not be able to attend the annual meeting in person.

In this proxy statement, we refer to Aspen Aerogels, Inc. as “Aspen Aerogels,” “the Company,” “we” and “us.”

This proxy statement relates to the solicitation of proxies by our board of directors for use at the annual meeting.

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IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE

ANNUAL STOCKHOLDER MEETING TO BE HELD ON JUNE 1, 2023

This proxy statement and our 2022 annual report to stockholders are available for viewing, printing and downloading at www.proxyvote.com. In order to view, print or download these materials, please have the 12-digit control number(s) that appears on your notice or proxy card available. On this website, you can also elect to receive future distributions of our proxy statements and annual reports to stockholders by electronic delivery.

Additionally, you can find a copy of our Annual Report on Form 10-K, which includes our financial statements, for the fiscal year ended December 31, 2022 on the website of the Securities and Exchange Commission, or the SEC, at www.sec.gov, or in the “SEC Filings” tab of the “Financial Information” subsection of the “Investors” section of our website at www.aerogel.com. You may also obtain a printed copy of our Annual Report on Form 10-K, including our financial statements, from us, free of charge, by sending a written request to:

Aspen Aerogels, Inc.

Attn: Investor Relations

26 Forest Street, Suite 200

Marlborough, Massachusetts, 01752

Exhibits will be provided upon written request and payment of an appropriate processing fee.

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CAUTIONARY INFORMATION AND FORWARD-LOOKING STATEMENTS

This proxy statement contains forward-looking statements about future events and circumstances. Generally speaking, any statement not based upon historical fact is a forward-looking statement. Forward-looking statements can also be identified by the use of forward-looking or conditional words such as “could,” “should,” “can,” “continue,” “estimate,” “forecast,” “intend,” “look,” “may,” “will,” “expect,” “believe,” “anticipate,” “plan,” “remain,” “confident” and “commit” or similar expressions. In particular, statements regarding our plans, strategies, prospects and expectations regarding our business and industry are forward-looking statements. They reflect our expectations, are not guarantees of performance and speak only as of the date of this proxy statement. Except as required by law, we do not undertake to update such forward-looking statements. You should not rely unduly on forward-looking statements. Our business results are subject to a variety of risks, including those that are described in our annual report on Form 10-K for the year ended December 31, 2022 and elsewhere in our filings with the Securities and Exchange Commission. If any of these considerations or risks materialize or intensify, our expectations (or underlying assumptions) may change and our performance may be adversely affected.

Website links included in this proxy statement are for convenience only. Information contained on or accessible through such website links is not incorporated herein and does not constitute a part of this proxy statement.

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IMPORTANT INFORMATION ABOUT THE ANNUAL MEETING AND VOTING

Why is the Company Soliciting My Proxy?

The board of directors of Aspen Aerogels is soliciting your proxy to vote at the 2023 Annual Meeting of Stockholders to be held virtually via live audio webcast, on Thursday, June 1, 2023 at 9:00 a.m. Eastern Time and any adjournments or postponements of the meeting, which we refer to as the annual meeting. This proxy statement along with the accompanying Notice of 2023 Annual Meeting of Stockholders summarizes the purposes of the meeting and the information you need to know to vote at the annual meeting.

Why Did I Receive a Notice in the Mail Regarding the Internet Availability of Proxy Materials Instead of a Full Set of Proxy Materials?

As permitted by the rules of the U.S. Securities and Exchange Commission, or the SEC, we may furnish our proxy materials to our stockholders by providing access to such documents on the Internet, rather than mailing printed copies of these materials to each stockholder. Most stockholders will not receive printed copies of the proxy materials unless they request them. We believe that this process should expedite stockholders’ receipt of proxy materials, lower the costs of the annual meeting and help to conserve natural resources. If you received the Notice by mail or electronically, you will not receive a printed or email copy of the proxy materials, unless you request one by following the instructions included in the Notice. Instead, the Notice instructs you as to how you may access and review all of the proxy materials and submit your proxy on the Internet. If you requested a paper copy of the proxy materials, you may authorize the voting of your shares by following the instructions on the proxy card, in addition to the other methods of voting described in this proxy statement.

Why Are You Holding a Virtual Annual Meeting?

Our 2023 Annual Meeting will be held in a virtual meeting format only. We have designed our virtual format to enhance, rather than constrain, stockholder access, participation and communication. For example, the virtual format allows stockholders to communicate with us in advance of, and during, the annual meeting so they can submit questions to our board of directors or management, as time permits.

What Happens if There Are Technical Difficulties During the Annual Meeting?

We will have technicians ready to assist you with any technical difficulties you may have accessing the virtual annual meeting, voting at the annual meeting or submitting questions at the annual meeting. If you encounter any difficulties accessing the virtual meeting during the check-in or meeting time, please call the technical support number that will be posted on the Virtual Shareholder Meeting login page.

Who Can Vote?

Only stockholders who owned our common stock at the close of business on April 4, 2023 are entitled to vote at the annual meeting. On this Record Date, there were 70,069,160 shares of our common stock outstanding and entitled to vote. Our common stock is our only class of voting stock.

If on the Record Date your shares of our common stock were registered directly in your name with our transfer agent, Computershare Trust Company, N.A., then you are a stockholder of record.

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If on the Record Date your shares were held not in your name, but rather in an account at a brokerage firm, bank, dealer or other similar organization, then you are the beneficial owner of shares held in “street name” and the Notice is being forwarded to you by that organization. The organization holding your account is considered to be the stockholder of record for purposes of voting at the annual meeting. As a beneficial owner, you have the right to direct your broker or other agent regarding how to vote the shares in your account. You are also invited to attend the annual meeting. However, since you are not the stockholder of record, you may not vote your shares at the annual meeting unless you request and obtain a valid proxy from your broker or other agent.

You do not need to attend the annual meeting to vote your shares. Shares represented by valid proxies, received in time for the annual meeting and not revoked prior to the annual meeting, will be voted at the annual meeting. For instructions on how to change or revoke your proxy, see “May I Change or Revoke My Proxy?” below.

How Many Votes Do I Have?

Each share of our common stock that you own entitles you to one vote.

How Do I Vote?

Whether you plan to attend the annual meeting or not, we urge you to vote by proxy. All shares represented by valid proxies that we receive through this solicitation, and that are not revoked, will be voted in accordance with your instructions on the proxy card or as instructed via the Internet or telephone. You may specify whether your shares should be voted FOR or WITHHELD for each nominee for director, and whether your shares should be voted FOR, AGAINST or ABSTAIN with respect to the other proposals. If you properly submit a proxy without giving specific voting instructions, your shares will be voted in accordance with our board of directors’ recommendations as noted below. Voting by proxy will not affect your right to attend the annual meeting. If your shares are registered directly in your name through our stock transfer agent, Computershare Trust Company, N.A., or you have stock certificates registered in your name, you may vote:

Telephone and Internet voting facilities for stockholders of record will be available 24 hours a day and will close at 11:59 p.m. Eastern Time on May 31, 2023.

If your shares are held in “street name” (held in the name of a bank, broker or other holder of record), you will receive instructions from the holder of record. You must follow the instructions of the holder of record in order for your shares to be voted. Telephone and Internet voting also will be offered to stockholders owning shares through certain banks and brokers. If your shares are not registered in your own name and you plan to vote your shares at the time of the virtual annual meeting, you should contact your broker or agent to obtain a legal proxy or broker’s proxy card and vote your shares online at the time of the meeting.

How Does the Board of Directors Recommend That I Vote on the Proposals?

The board of directors recommends that you vote as follows:

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If any other matter is presented at the annual meeting, your proxy provides that your shares will be voted by one or both of the proxy holders listed in the proxy in accordance with their best judgment. At the time this proxy statement was first made available, we knew of no matters that needed to be acted on at the annual meeting, other than those discussed in this proxy statement.

May I Change or Revoke My Proxy?

If you give us your proxy, you may change or revoke it at any time before the annual meeting. You may change or revoke your proxy in any one of the following ways:

Your most current vote, whether by telephone, Internet or proxy card, is the vote that will be counted.

What if I Receive More Than One Notice or Proxy Card?

You may receive more than one Notice or proxy card if you hold shares of our common stock in more than one account, which may be in registered form or held in street name. Please vote in the manner described above under “How Do I Vote?” for each account to ensure that all of your shares are voted.

Will My Shares be Voted if I Do Not Vote?

If your shares are registered in your name or if you have stock certificates, they will not be counted if you do not vote as described above under “How Do I Vote?” If your shares are held in street name and you do not provide voting instructions to the bank, broker or other nominee that holds your shares as described above, the bank, broker or other nominee that holds your shares has the authority to vote your unvoted shares only on the amendment to our Restated Certificate of Incorporation to increase the number of shares of our common stock authorized for issuance (Proposal 3 of this proxy statement) and the ratification of the appointment of our independent registered public accounting firm (Proposal 5 of this proxy statement) without receiving instructions from you. Therefore, we encourage you to provide voting instructions to your bank, broker or other nominee. This ensures your shares will be voted at the annual meeting and in the manner you desire. A “broker non-vote” will occur if your broker cannot vote your shares on a particular matter because it has not received instructions from you and does not have discretionary voting authority on that matter or because your broker chooses not to vote on a matter for which it does have discretionary voting authority.

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Your bank, broker or other nominee does not have the ability to vote your uninstructed shares in the election of directors (Proposal 1 of this proxy statement) or approving an amendment to our Restated Certificate of Incorporation to reflect new Delaware law provisions regarding officer exculpation (Proposal 2 of this proxy statement). In addition, your bank, broker or other nominee is prohibited from voting your uninstructed shares on any matters related to our equity compensation or executive compensation (Proposals 4 and 6 of this proxy statement, respectively). Therefore, if you hold your shares in street name, it is critical that you cast your vote if you want your vote to be counted for Proposals 1, 2, 4, and 6 of this proxy statement.

Who Can I Call if I Have Questions?

We have retained The Laurel Hill Advisory Group, LLC (“Laurel Hill”) to assist shareholders. If you have any questions or need assistance with your vote, please reach out to Laurel Hill by phone at 888-742-1305 or email at aspenaerogels@laurelhill.com.

What Vote is Required to Approve Each Proposal and How are Votes Counted?

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Is Voting Confidential?

We will keep all the proxies, ballots and voting tabulations private. We only let our Inspectors of Election, representatives of Broadridge Investor Communication Solutions, Inc., examine these documents. Management will not know how you voted on a specific proposal unless it is necessary to meet legal requirements. We will, however, forward to management any written comments you make on the proxy card or that you otherwise provide.

Where Can I Find the Voting Results of the Annual Meeting?

The preliminary voting results will be announced at the annual meeting, and we will publish preliminary, or final results if available, in a Current Report on Form 8-K within four business days of the annual meeting. If final results are unavailable at the time we file the Form 8-K, then we will file an amended report on Form 8-K to disclose the final voting results within four business days after the final voting results are known.

What Are the Costs of Soliciting these Proxies?

Our directors and employees are soliciting proxies for the annual meeting from stockholders. We will pay these employees and directors no additional compensation for these services. We will ask banks, brokers and other institutions, nominees and fiduciaries to forward these proxy materials to their principals and to obtain authority to execute proxies. We will then reimburse them for their expenses.

Additionally, we have engaged Laurel Hill to act as our proxy solicitor in connection with the proposals to be acted upon at our annual meeting. Pursuant to our agreement with Laurel Hill, Laurel Hill will, among other things, provide advice regarding proxy solicitation issues and solicit proxies from our stockholders on our behalf in connection with the annual meeting. For these services, we will pay a fee of approximately $15,000 plus expenses.

What Constitutes a Quorum for the Annual Meeting?

The presence, at the meeting virtually or by proxy, of the holders of a majority of the voting power of all outstanding shares of our common stock entitled to vote at the annual meeting is necessary to constitute a

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quorum at the annual meeting. Votes of stockholders of record who are present at the annual meeting virtually or by proxy, abstentions, and broker non-votes are counted for purposes of determining whether a quorum exists.

Attending the Annual Meeting

The annual meeting will be held at 9:00 a.m. Eastern Time on Thursday, June 1, 2023. This year, our annual meeting will be held in a virtual meeting format only.

To attend the virtual annual meeting, go to www.virtualshareholdermeeting.com/ASPN2023 shortly before the meeting time, and follow the instructions for downloading the webcast. If you miss the annual meeting, you can view a replay of the webcast at the same location at least six months from the meeting. You need not attend the annual meeting in order to vote.

Householding of Annual Disclosure Documents

SEC rules concerning the delivery of annual disclosure documents allow us or your broker to send a single Notice or, if applicable, a single set of our proxy materials to any household at which two or more of our stockholders reside, if we or your broker believe that the stockholders are members of the same family. This practice, referred to as “householding,” benefits both you and us. It reduces the volume of duplicate information received at your household and helps to reduce our expenses. The rule applies to our Notices, annual reports, proxy statements and information statements. Once you receive notice from your broker or from us that communications to your address will be “householded,” the practice will continue until you are otherwise notified or until you revoke your consent to the practice. Stockholders who participate in householding will continue to have access to and utilize separate proxy voting instructions.

If your household received a single Notice or, if applicable, a single set of proxy materials this year, but you would prefer to receive your own copy, please contact our transfer agent, Computershare Trust Company, N.A., by calling their toll free number, 1-800-368-5948.

If you do not wish to participate in householding and would like to receive your own Notice or, if applicable, set of Aspen Aerogels proxy materials in future years, follow the instructions described below. Conversely, if you share an address with another Aspen Aerogels stockholder and together both of you would like to receive only a single Notice or, if applicable, set of proxy materials, follow these instructions:

TRADEMARKS, TRADE NAMES AND SERVICE MARKS

We own or have rights to use “Aspen Aerogels,” “Cryogel,” “Pyrogel,” “PyroThin”, “Spaceloft,” the Aspen Aerogels logo and other trademarks, service marks and trade names of Aspen Aerogels appearing in this document. Solely for convenience, the trademarks, service marks and trade names referred to in this document are without the ^® and TM symbols, but such references are not intended to indicate, in any way, that the owner thereof will not assert, to the fullest extent under applicable law, such owner’s rights to these trademarks, service marks and trade names.

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SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The following table sets forth certain information with respect to the beneficial ownership of our common stock as of April 1, 2023 for (a) the executive officers named in the Summary Compensation Table on page 34 of this proxy statement, (b) each of our directors and director nominees, (c) all of our current directors and executive officers as a group and (d) each stockholder known by us to own beneficially more than 5% of our common stock.

Beneficial ownership is determined in accordance with the rules of the SEC and includes voting or investment power with respect to the securities. We deem shares of common stock that may be acquired by an individual or group within 60 days of April 1, 2023 pursuant to the exercise of options or warrants or the vesting of restricted stock units (“RSUs”) to be outstanding for the purpose of computing the percentage ownership of such individual or group, but are not deemed to be outstanding for the purpose of computing the percentage ownership of any other person shown in the table.

Except as indicated in footnotes to this table, we believe that the stockholders named in this table have sole voting and investment power with respect to all shares of common stock shown to be beneficially owned by them based on information provided to us by these stockholders. Percentage of ownership is based on 70,069,160 shares of common stock outstanding on April 1, 2023.

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MANAGEMENT AND CORPORATE GOVERNANCE

The Board of Directors

Our Restated Certificate of Incorporation and Restated Bylaws provide that our business is to be managed by or under the direction of our board of directors. Our board of directors is divided into three classes for purposes of election. One class is elected at each annual meeting of stockholders to serve for a three-year term. Our board of directors currently consists of eight members classified into three classes as follows: (1) Steven R. Mitchell, Richard F. Reilly and Donald R. Young constitute the Class III directors and their current terms will expire at the 2023 annual meeting of stockholders, (2) Rebecca B. Blalock and James E. Sweetnam constitute the Class I directors and their current terms will expire at the 2024 annual meeting of stockholders, and (3) Mark L. Noetzel, William P. Noglows and Kathleen M. Kool constitute the Class II directors and their current terms will expire at the 2025 annual meeting of stockholders.

On March 8, 2023, our board of directors accepted the recommendation of the nominating and governance committee and voted to nominate Steven R. Mitchell and Donald R. Young for re-election at the annual meeting for a term of three years to serve until the 2026 annual meeting of stockholders, and until their respective successors have been elected and qualified. Mr. Reilly will not stand for reelection at the end of his current term, which ends at the 2023 annual meeting of stockholders.

Set forth below are the names of those persons nominated for election as directors at the 2023 annual meeting and those directors whose terms do not expire this year, their ages, their positions in the Company, if any, their principal occupations or employment for at least the past five years, the length of their tenure as directors and the names of other public companies in which such persons hold or have held directorships during the past five years. Additionally, information about the specific experience, qualifications, attributes or skills that led to our board of directors’ conclusion at the time of filing of this proxy statement that each person listed should serve as a director is set forth below:

Donald R. Young has been our President, Chief Executive Officer and a member of our board of directors since November 2001. Prior to joining us, Mr. Young worked in the United States and abroad in a broad range of senior operating roles for Cabot Corporation, a leading global specialty chemical company. Prior to Cabot Corporation, Mr. Young worked in the investment business at Fidelity Management & Research. Mr. Young holds a BA from Harvard College and an MBA from Harvard Business School. The board has concluded that Mr. Young possesses specific attributes that qualify him to serve as a member of our board of directors, including the perspective and experience he brings as our Chief Executive Officer, which brings historic knowledge, operational expertise and continuity to our board of directors.

Rebecca B. Blalock has served on our board of directors since June 2016. Ms. Blalock is a partner at Advisory Capital LLC, which provides strategic consulting in the areas of energy and information technology. She has served in that role since October 2011. From October 2002 to October 2011, Ms. Blalock was Senior Vice President and Chief Information Officer of Southern Company, a Fortune 500 energy company. From 1979 to October 2002, Ms. Blalock served in various positions at Georgia Power and Southern Company Services, which are subsidiaries of Southern Company. Ms. Blalock’s management experience during her tenure at

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Georgia Power included serving as Vice President of Community and Economic Development from January 2000 to October 2002 and Director, Corporate Communication from February 1996 to February 2000. She currently serves on the Advisory Boards of Valor Ventures LLC and HData LLC. She is also a board member of 1910 Legacy, which is an employee -owned company, and she chairs the nomination and governance committee of this board. She previously served on the Board of Directors of Hannon Armstrong Sustainable Infrastructure Capital, Inc. (NYSE: HASI), including on its Compensation Committee from March 15, 2017 until July 31, 2019 and on its Finance and Risk Committee from May 15, 2017 until July 31, 2019. She also serves on the Board of Councilors of The Carter Center and was elected to the State of Georgia’s Humanities Board. Ms. Blalock holds a BBA in Marketing from State University of West Georgia and an MBA in Finance from Mercer University. Ms. Blalock also completed the Program for Management Development (PMD) at Harvard Business School, received a cyber-security certificate from the Georgia Institute of Technology in 2017 and a Cyber Risk Oversight Certificate from the National Association of Corporate Directors in 2018. The board has concluded that Ms. Blalock possesses specific attributes that qualify her to serve as a member of our board of directors, including the strategic insight, expertise and experience she has developed in senior executive management at a Fortune 500 company in the energy industry, particularly with information technology, as well as her experience with the business environment in Georgia. In addition, because Ms. Blalock has served on many boards of directors, the board has concluded that she has substantial experience regarding how boards can and should effectively oversee and manage companies as well as a significant understanding of governance issues.

Kathleen M. Kool has served on our board of directors since November 2022. Ms. Kool most recently served as the CEO of Tide Cleaners, a wholly owned subsidiary of Procter & Gamble (“P&G”), until her retirement in June 2022. Under Ms. Kool’s leadership as CEO, Tide Cleaners grew from 35 to 191 stores and was ranked 76th in Entrepreneur’s Franchise 500 ranking, marking the third consecutive year in the top 100. During her 27-year tenure at P&G, Ms. Kool served in a variety of executive leadership roles, including CFO of North America Fabric Care, the largest regional business unit at P&G, with over $8 billion in retail sales, and CFO of the Global P&G Professional business. In addition to her extensive business leadership experience, Ms. Kool was a key member of P&G’s award-winning Investor Relations team, partnering with multiple CEOs and leading the communication for the strategy renewal that spanned two $10 billion productivity programs and a more focused portfolio of strategic brands. Additionally, Ms. Kool led numerous acquisitions, integrations, and business expansions, and navigated Tide Cleaners through the COVID-19 pandemic, growing industry share, opening new stores and overseeing expansion to new campuses. Ms. Kool is also a member of the Board of Directors of Digimarc Corporation, where she chairs the Compensation and Talent Management Committee and serves on the Audit and the Governance, Nominating, and Sustainability Committees. Ms. Kool received her BA, summa cum laude, in Economics from Kalamazoo College and her MBA from Washington University in St. Louis. The board has concluded that Ms. Kool possesses specific attributes that qualify her to serve as a member of our board of directors, including her extensive senior-level management experience in financial reporting and accounting, investor relations, general business operations, complex business integration, corporate governance, and other public company board service.

Steven R. Mitchell has served on our board of directors since August 2009. Mr. Mitchell has served as the Chief Executive Officer of Argonaut Private Capital L.P. since July 2016, prior to which he was the managing director of Argonaut Private Equity, LLC, or Argonaut, since November 2004. Prior to joining Argonaut, Mr. Mitchell was a principal in both Radical Incubation and 2929 Entertainment. He currently serves on the boards of directors of several public and privately owned companies, including Stepstone Group; Alkami Technology, Inc.; S&R Compression, LLC; DMB Pacific, LLC; Downing Wellhead Equipment LLC; The Fred Jones Companies, LLC; JAC Holding Enterprises, Inc.; QRC Valve Distributors LLC; SEF Energy, LLC; Mammoth Carbon Products, LLC; MT Group Holdings, LLC; American Cementing, LLC; McNellies Group LLC; and Mark Young Construction, LLC. From 1996 to 1999, Mr. Mitchell was a corporate attorney at Gibson, Dunn & Crutcher LLP. Mr. Mitchell holds a BBA in Marketing from Baylor University and a JD from University of San Diego School of Law. The board has concluded that Mr. Mitchell possesses specific attributes that qualify him to serve as a member of our board of directors, including his experience building, investing in and growing several manufacturing, technology and product companies and his experience with sophisticated

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transactions as a corporate attorney. In addition, because Mr. Mitchell has served on many boards of directors, the board has concluded that he has substantial experience regarding how boards can and should effectively oversee and manage companies, and a significant understanding of governance issues.

Mark L. Noetzel has served on our board of directors since December 2009. Mr. Noetzel has worked as a consultant to a number of public and private companies since May 2009. From July 2019 to May 2021, he was a Managing Director of Akoya Capital Partners, LLC, working in the specialty chemicals segment. From June 2007 to May 2009, Mr. Noetzel was President and Chief Executive Officer of Cilion, Inc., a biofuels company. Prior to joining Cilion in 2007, he had served in several senior positions at BP plc, including Group Vice President, Global Retail, from 2003 until 2007, Group Vice President, B2B Fuels and New Markets, during 2001 and 2002 and Group Vice President, Chemicals, from 1997 until 2001. Prior to those senior management roles with BP plc, Mr. Noetzel served in other management and non-management roles with Amoco Corporation from 1981 until BP acquired Amoco in 1998. Mr. Noetzel served on the board of directors of Axiall Corporation (NYSE: AXLL) from September 2009 until Axiall was acquired by Westlake Chemical Corporation in August 2016. Mr. Noetzel served as Chairperson of Axiall from January 2010 to March 2016. Mr. Noetzel also previously served on the board of Siluria Technologies Inc., a privately owned technology company until May 2019 and on the board of Dixie Chemical Company Inc., also privately owned, from September 2017 to November 2018. Mr. Noetzel holds a BA in Political Science from Yale University and an MBA from the Wharton School at University of Pennsylvania. The board has concluded that Mr. Noetzel possesses specific attributes that qualify him to serve as a member of our board of directors, including more than ten years of experience in senior executive management roles with large, international businesses within the chemical and fuel industries and his experience as chairperson of the board of a public company.

James E. Sweetnam has served on our board of directors since August 2022. Mr. Sweetnam served as President and CEO, and a member of the board, of Dana Corporation, a Fortune 500 world leader in the design and manufacture of driveline components for light, medium and heavy-duty vehicle manufacturers in the automotive, commercial vehicle and off-highway markets. Previously, he served in various roles of increasing responsibility, including as CEO of Truck Group, at Eaton Corporation, a global, diversified power management company, after serving in a variety of other roles at Eaton Corporation. Prior to joining Eaton, Mr. Sweetnam spent 10 years at Cummins Inc., a diesel and natural gas engine designer, manufacturer, and distributor, where he served as VP, Cummins Engine Company and Group Managing Director of Holset Engineering Co. Ltd., a Cummins subsidiary and manufacturer of turbochargers, headquartered in England. Prior to that, he served as President of Cummins Electronics Company. Mr. Sweetnam has also held management positions with Canadian Liquid Air and engineering positions with Air Products and Chemicals in Allentown, PA and São Paulo, Brazil. He presently serves on the board of directors of Republic Airways Holdings, Inc., an airline holding corporation, on which he is a member of its audit and finance committee and its nominating and governance committee. He previously served on the board of directors of SunCoke Energy, Inc., including as chair of its nominating and

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governance committee and chair of its compensation committee. Mr. Sweetnam received his B.S. in Applied Science and Engineering from the United States Military Academy, West Point, and his MBA from Harvard Business School. The board has concluded that Mr. Sweetnam possesses specific attributes that qualify him to serve as a member of our board of directors, including his extensive senior-level management experience in general business operations, manufacturing and engineering, his automotive industry experience, and his background in international business development, as well as his service on a number of public company boards.

Board of Director Qualifications, Expertise, Attributes and Diversity

Financial – Experience leading or managing the financial function of an enterprise, resulting in proficiency in complex financial management, capital allocation and financial reporting. Experience or expertise in financial accounting and reporting processes or the financial management of a major organization.
Leadership – Experience leading a significant enterprise, resulting in a practical understanding of organizations, processes, strategic planning and risk management. Demonstrated strengths in developing talent planning succession and driving change and long-term growth.
Technology and Cybersecurity – Significant background working in information technology and/or cybersecurity, resulting in knowledge of how to anticipate technological trends, including digital transformation, data governance, information security and development of new business models. Significant expertise and experience in leading information technology and/or cybersecurity functions of an enterprise.
Public Company Governance – Experience serving as a director of public company, which enables one to understand the dynamics and operation of a corporate board, the relationship of a public company board to the CEO and other senior management personnel, the legal and regulatory landscape in which public companies must operate, the importance of particular agenda and oversight issues, and how to oversee an ever-changing mix of strategic, operational and compliance-related matters.
Manufacturing and Project Management – Experience scaling up manufacturing significantly and managing large scale projects, including the construction of plants.

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Director Independence

Our board of directors has reviewed the materiality of any relationship that each of our directors has with Aspen Aerogels, either directly or indirectly. Based upon this review, our board has determined that all of our directors other than Donald R. Young, our President and Chief Executive Officer, are “independent directors” as defined by the New York Stock Exchange.

Committees of the Board of Directors and Meetings

Meeting Attendance. During the fiscal year ended December 31, 2022, there were 14 meetings of our board of directors, and the various committees of the board met a total of 22 times. No director attended fewer than 75% of the total number of meetings of the board and of committees of the board on which he or she served during fiscal year 2022. The board has adopted a policy under which each member of the board is strongly encouraged but not required to attend each annual meeting of our stockholders. All of our directors attended the annual meeting of our stockholders held in 2022.

Audit Committee. Our audit committee met 11 times during fiscal year 2022. This committee currently has five members, Richard F. Reilly (chair), Rebecca B. Blalock, Kathleen M. Kool, Mark L. Noetzel and James E. Sweetnam. Our audit committee’s role and responsibilities are set forth in the audit committee’s written charter and include the authority to retain and terminate the services of our independent registered public accounting

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firm. In addition, the audit committee reviews our annual and quarterly financial statements, considers matters relating to accounting policy and internal controls and reviews the scope of annual audits. All members of the audit committee satisfy the current independence standards promulgated by the SEC and by the New York Stock Exchange, as such standards apply specifically to members of audit committees. Our board of directors has determined that Mr. Reilly and Ms. Kool are an “audit committee financial expert,” as the SEC has defined that term in Item 407 of Regulation S-K.

Our audit committee is authorized to, among other matters:

Our audit committee typically meets quarterly and with greater frequency as necessary. The agenda for each meeting is set by the chair of the audit committee in consultation with the Chief Executive Officer, Chief Financial Officer and Corporate Secretary. The audit committee meets regularly in executive session. However, from time to time, various members of management, and employees, outside advisors or consultants may be invited by the audit committee to make presentations, to provide financial, background information or advice, or to otherwise participate in audit committee meetings.

Please also see the report of the audit committee set forth elsewhere in this proxy statement.

A copy of the audit committee’s written charter is publicly available in the “Investors” section of our website at www.aerogel.com.

Compensation and Leadership Development Committee. Our compensation and leadership development committee (hereafter also referred to as our “compensation committee”) met six times during fiscal 2022. This committee currently has four members, Mark L. Noetzel (chair), Steven R. Mitchell, William P. Noglows and James E. Sweetnam. Robert M. Gervis, a former member of our board of directors, served as chair of the compensation committee until his resignation from our board of directors and all committees thereof, effective November 1, 2022. Our compensation committee’s role and responsibilities are set forth in its written charter and includes reviewing, approving and making recommendations regarding our compensation policies, practices and procedures to ensure that legal and fiduciary responsibilities of the board of directors are carried out and that such policies, practices and procedures contribute to our success. Our compensation committee also administers our 2014 Employee, Director and Consultant Equity Incentive Plan (the “2014 Plan”) and our employee cash bonus plan. The compensation committee is responsible for the determination of the compensation of our executive officers other than our Chief Executive Officer. The compensation of our Chief Executive Officer is determined by our board of directors upon the recommendation of our compensation committee. All members of the compensation committee qualify as independent under the definition promulgated by the New York Stock Exchange.

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Our compensation committee is authorized to, among other matters:

Our compensation committee typically meets quarterly and with greater frequency if necessary. The agenda for each meeting is set by the chair of the compensation committee in consultation with the Chief Executive Officer, the Corporate Secretary and the Senior Vice President of Human Resources. The compensation committee meets regularly in executive session. However, from time to time, various members of management and other employees as well as outside advisors or consultants may be invited by the compensation committee to make presentations, to provide financial or other background information or advice, or to otherwise participate in compensation committee meetings. The Chief Executive Officer does not participate in and is not present during any deliberations or determinations of the board of directors or the compensation committee regarding his compensation.

The compensation committee has the sole authority to obtain, at the expense of the Company, advice and assistance from compensation consultants, legal counsel, experts and other advisors that the compensation committee deems advisable in the performance of its duties. The compensation committee has the sole authority to approve any such consultants’ or advisors’ fees and other retention terms. The compensation committee may select any such consultant, counsel, expert or advisor to the compensation committee, only after taking into consideration factors that bear upon the advisor’s independence. The compensation committee has engaged Meridian Compensation Partners, LLC (“Meridian”) as its compensation consultant since 2014. The compensation committee assessed the independence of Meridian pursuant to SEC rules and other factors and concluded that Meridian’s work for the compensation committee does not raise any conflict of interest nor affect its independence.

Generally, the compensation committee’s process involves the establishment of corporate goals and objectives for the current year and determination of compensation levels. For executives other than the Chief Executive Officer, the compensation committee solicits and considers evaluations and recommendations submitted to the committee by the Chief Executive Officer. In the case of the Chief Executive Officer, the evaluation is conducted by the compensation committee, which recommends any adjustments to his compensation levels and arrangements for approval by the board of directors. For all executives, as part of its deliberations, the compensation committee may review and consider, as appropriate, materials such as financial reports and projections, operational data, tax and accounting information, total compensation that may become payable to executives in various hypothetical scenarios, executive stock ownership information, Company stock performance data, analyses of historical executive compensation levels and current Company-wide compensation levels and recommendations of the compensation committee’s compensation consultant, if any, including analyses of executive compensation paid at other companies.

For 2022, Meridian assisted the compensation committee in fulfilling its responsibilities under its charter, including advising on compensation packages for executive officers, compensation program design and market practices generally. The compensation committee authorized Meridian to interact with management on behalf of the compensation committee, as needed in connection with advising the compensation committee, and Meridian participates in discussions with management and, when appropriate, outside legal counsel with respect to matters under consideration by the compensation committee.

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A copy of the compensation committee’s written charter is publicly available in the “Investors” section of our website at www.aerogel.com.

Nominating, Governance and Sustainability Committee. Our nominating, governance and sustainability committee met five times during fiscal year 2022 and currently has four members, Rebecca B. Blalock (chair), Kathleen M. Kool, Mark L. Noetzel and William P. Noglows. Robert M. Gervis, a former member of our board of directors, served as a member of the nominating, governance and sustainability committee until his resignation from our board of directors and all committees thereof, effective November 1, 2022. The nominating, governance and sustainability committee’s role and responsibilities are set forth in its written charter and include evaluating and making recommendations to the full board as to the size and composition of the board and its committees; monitoring and evaluating legal and regulatory trends and developments relating to corporate governance matters; making recommendations to the full board intended to help us and the board maintain appropriate corporate governance policies and practices; regularly reviewing and evaluating our relevant environmental, sustainability, social and corporate responsibility strategies, policies, programs, practices and reports; evaluating and making recommendations as to potential candidates to serve on our board of directors and its committees; and evaluating current board members’ performance. All members of the nominating, governance and sustainability committee qualify as independent under the definition promulgated by the New York Stock Exchange.

Our nominating, governance and sustainability committee is authorized to, among other matters:

Our nominating, governance and sustainability committee may consider candidates recommended by stockholders as well as from other sources such as other directors or officers, third-party search firms or other appropriate sources. Once identified, the nominating, governance and sustainability committee will evaluate a candidate’s qualifications in accordance with our “Criteria for Nomination as a Director” appended to the committee’s written charter. Threshold criteria include a candidate’s personal integrity and sound judgment, business and professional skills and experience, independence, knowledge of our industry, possible conflicts of interest, diversity, the extent to which the candidate would fill a present need on the board, and concern for the long-term interests of our stockholders.

If a stockholder wishes to propose a candidate for consideration as a nominee for election to our board of directors, the stockholder must follow the procedures described in our restated bylaws and in “Stockholder Proposals and Nominations for Director” at the end of this proxy statement. In general, persons recommended by stockholders will be considered in accordance with our “Policies and Procedures for Shareholders Submitting Nominating Recommendations” appended to our nominating, governance and sustainability committee’s written charter. All stockholder recommendations for proposed director nominees must be addressed in writing to the nominating, governance and sustainability committee, in care of our Corporate Secretary, at our principal offices and must be received by the deadlines set forth in this proxy statement under the heading “Stockholder Proposals and Nominations for Director.” The recommendation must be accompanied by the following information concerning each stockholder making the recommendation and the beneficial owner, if any, on whose behalf the nominations is made:

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The recommendation must be accompanied by the following information concerning the proposed nominee:

The recommending stockholder must also furnish a statement supporting the stockholder’s view that the proposed nominee possesses the minimum qualifications prescribed by the committee for nominees, and describing the contributions that the nominee would be expected to make to the board and to the governance of the Company. The recommending stockholder must state whether, in its view, the proposed nominee, if elected, would represent all stockholders and not serve for the purpose of advancing or favoring any particular stockholder or other constituency of the Company. The recommendation must be accompanied by the written consent of the proposed nominee: (a) to be considered by the committee and interviewed if the committee chooses to do so in its discretion, and (b) if nominated and elected, to serve as a director.

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If a recommendation is submitted by a group of two or more stockholders, the information regarding recommending stockholders set forth above must be submitted with respect to each stockholder in the group.

Our nominating, governance and sustainability committee has not adopted a formal diversity policy in connection with the consideration of director nominations or the selection of nominees. However, the nominating, governance and sustainability committee considers issues of diversity and inclusion among its members in identifying and considering nominees for director, and will strive where appropriate to achieve a diverse and inclusive balance of backgrounds, perspectives, experience, age, gender, ethnicity, sexual orientation and national origin on the board of directors and its committees.

A copy of the nominating, governance and sustainability committee’s written charter and our corporate governance guidelines are publicly available on the Investors section of our website at www.aerogel.com.

Compensation Committee Interlocks and Insider Participation

During our last fiscal year, the members of our compensation committee included Mark L. Noetzel (chair), Steven R. Mitchell, William P. Noglows, James E. Sweetnam and Robert M. Gervis (former chair). No member of our compensation committee has at any time been an employee of the Company. None of our executive officers serves as a member of another entity’s board of directors or compensation committee that has one or more executive officers serving as a member of our board of directors or compensation committee.

Board Leadership Structure and Role in Risk Oversight

The positions of Chairperson of the Board and Chief Executive Officer are presently separated at our Company. We believe that separating these positions allows our Chief Executive Officer to focus on our day-to-day business, while allowing our Chairperson of the Board to lead the board of directors in its fundamental role of providing advice to, and independent oversight of, management. Our board of directors recognizes the time, effort and energy that the Chief Executive Officer is required to devote to his position in the current business environment, as well as the commitment required to serve as our Chairperson of the Board, particularly as the board of directors’ oversight responsibilities continue to expand. Our board of directors also believes that this structure ensures a greater role for the independent directors in the oversight of our Company and active participation of the independent directors in setting agendas and establishing priorities and procedures for the work of our board of directors. Our board of directors believes its administration of its risk oversight function has not affected its leadership structure.

Our board of directors administers its risk oversight function directly and through its committees. The audit committee receives regular reports from members of senior management on areas of material risk to the Company, including operational, financial, legal, regulatory, ethics and compliance, strategic and reputational risks. The audit committee also periodically reviews our enterprise risk management and cybersecurity programs. As part of its charter, our audit committee regularly discusses with management our major risk exposures, their potential financial and other impacts on our Company, and the steps we take to mitigate and manage them. In addition, our compensation committee assists the board of directors in fulfilling its oversight responsibilities with respect to the management and risks arising from our compensation policies and programs. Our nominating, governance and sustainability committee assists the board of directors in fulfilling its oversight responsibilities with respect to the management of risks associated with board organization, membership and structure, succession planning for our directors and executive officers, environmental, social and sustainability initiatives, and corporate governance.

Stockholder Communications to the Board

Generally, stockholders and other interested parties who have questions or concerns should contact our Investor Relations team at 508-691-1111. However, any stockholders and other interested parties who wish to address questions regarding our business directly with the board of directors, or any individual director, must prepare the communication in written form and mail or hand deliver the same to the following address:

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ATTN: SECURITY HOLDER COMMUNICATION

Board of Directors

Aspen Aerogels, Inc.

30 Forbes Road, Building B

Northborough, MA 01532

Such communications should not exceed 500 words in length and must be accompanied by the following information: a statement of the (i) type and amount of the securities of the Company that the person holds or (ii) a description of the person’s interest in the Company; any special interest, meaning an interest not in the capacity as a stockholder of the Company, that the person has in the subject matter of the communication; and the address, telephone number and e-mail address, if any, of the person submitting the communication.

The following types of communications are not appropriate for delivery to directors under these procedures: communications regarding individual grievances or other interests that are personal to the party submitting the communication and could not reasonably be construed to be of concern to security holders or other constituencies of the Company (such as employees, members of the communities in which we operate our businesses, customers and suppliers) generally; communications that advocate engaging in illegal activities; communications that, under community standards, contain offensive, scurrilous or abusive content; and communications that have no rational relevance to the business or operations of the Company.

Communications will be distributed to the board, or to any individual director or directors as appropriate, depending on the facts and circumstances outlined in the communications. Items that are unrelated to the duties and responsibilities of the board may be excluded, such as: junk mail and mass mailings; resumes and other forms of job inquiries; surveys; and solicitations or advertisements.

In addition, any material that is unduly hostile, threatening, or illegal in nature may be excluded, in which case it will be made available to any outside director upon request.

Executive Officers

The following table sets forth certain information regarding our executive officers who are not also directors, as of April 1, 2023. We have employment agreements with our Chief Executive Officer and the following executive officers:

Kelley W. Conte has been our Senior Vice President, Human Resources, since March 2021 and has previously served as our Vice President of Human Resources. Prior to joining Aspen Aerogels in September 2015, Ms. Conte was a Senior Director, Human Resources at EMC Corporation where she was the global head of Human Resources for the Enterprise Storage Division, as well as a global lead for the company-wide deployment of a cloud based HRIS solution. Ms. Conte has over 30 years of experience as a Human Resources leader in both large and small companies across the high tech and financial services industries. She holds a BS in Business Management with a concentration in Human Resources from Fairfield University.

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Virginia H. Johnson is our Chief Legal Officer, General Counsel, Corporate Secretary and Chief Compliance Officer. Prior to joining us in May 2022, Ms. Johnson was General Counsel of Schneider Electric North America, and before that, she served as Senior Vice President, Associate General Counsel & Secretary of Global Atlantic Financial Group. Ms. Johnson has 20 years of legal experience spanning both private practice and in-house executive leadership roles in the energy and financial services industries. Prior to moving in-house as corporate counsel, Ms. Johnson was a partner in the Litigation Department of Prince Lobel Tye LLP in Boston, and before that, she was an Associate in the Litigation/Regulatory Department, Securities/Corporate Governance Group, in the New York and Boston offices of Weil, Gotshal & Manges LLP. Ms. Johnson holds a Juris Doctor from the Cardozo School of Law, Yeshiva University, and a B.A. in Political Science from Boston University.

Gregg R. Landes has been with us since September 2016 and has served as Senior Vice President, Operations and Strategic Development since October 2019. Mr. Landes has previously served in a variety of positions with us, as our Vice President, Strategic Development and Operational Excellence from May 2018 to October 2019, Vice President, Innovation and Strategic Development from February 2018 to May 2018 and our Vice President, Finance and Corporate Development from September 2016 to February 2018. Prior to joining us, Mr. Landes was a principal at the consulting firm, Tetra Tech, Inc., where he focused on LNG and Environmental Bankruptcy trusts from July 2013 to August 2016. Prior to Tetra Tech, Mr. Landes was employed by Hess Corporation, where he served as Vice President, Business Development for Hess LNG from June 2007 to July 2013. Prior to Hess Corporation, Mr. Landes worked in a broad range of senior financial and business leadership roles for Cabot Corporation. Mr. Landes holds a BSBA in Finance from the University of Florida and an MBA from the F.W. Olin Graduate School of Business at Babson College. 

Ricardo C. Rodriguez has been our Chief Financial Officer since April 2022. Mr. Rodriguez previously served as our Chief Strategy Officer from November 2021. Prior to joining Aspen, from February 2019 to November 2021, Mr. Rodriguez was a Corporate Strategy Director at Aptiv, a $15 billion automotive technology company where he led the establishment of its Vehicle Electrification Systems group, among other value-adding initiatives. From April 2010 to February 2019, he served in a variety of finance, planning and P&L leadership roles at ClearMotion, GM’s OnStar division, Amazon and Fiat Chrysler Automobiles (now Stellantis). In addition, Mr. Rodriguez worked as an investment banker at Lazard, where he focused on automotive M&A and restructuring advisory. Mr. Rodriguez received his Bachelor of Science degree in Mechanical Engineering from General Motors Institute / Kettering University while working at Magna International and holds an MBA from Harvard Business School.

Keith L. Schilling has been our Senior Vice President, Technology since January 2022. Mr. Schilling previously served as our Vice President, Sales from October 2021 to January 2022. Currently, Mr. Schilling continues to lead the sales function for Energy Industrial and Thermal Barrier in addition to the technology function. Prior to joining Aspen, from December 2019 to October 2021, Mr. Schilling served as Chief Executive Officer of Basic Energy Services, Inc., an upstream oil and gas services provider. From September 1995 to December 2019, Mr. Schilling held senior level commercial and technology leadership roles at Schlumberger, Tetra Technologies, the combined Baker Hughes and GE Oil & Gas Companies, both domestically and internationally. Mr. Schilling received his Bachelor of Science degree in Chemical Engineering from Texas A&M University and holds an MBA from Erasmus University in the Netherlands.

Corby C. Whitaker has been our Senior Vice President, Sales and Marketing since joining us in February 2012. Prior to that, Mr. Whitaker worked in senior sales, marketing and business development leadership roles in the energy, renewable energy, building materials and industrial equipment industries. From July 2010 to December 2011, Mr. Whitaker was Vice President, Sales at Solyndra LLC and from December 2007 to July 2010, Mr. Whitaker served as Vice President, Global Sales at United Solar Ovonic LLC, each a solar technology company. Prior to that, from March 2004 to December 2007, Mr. Whitaker served as Director of Sales at Johns Manville. Mr. Whitaker received his Bachelor of Science degree in Mechanical Engineering from Texas A&M University.

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COMPENSATION DISCUSSION AND ANALYSIS

This section discusses the principles underlying our policies and decisions with respect to the compensation of our executive officers who are named in the Summary Compensation Table below, or our “named executive officers,” and all material factors relevant to an analysis of these policies and decisions. During 2022, the following were our named executive officers:

Compensation Overview

This “Compensation Overview” section discusses the compensation programs and policies for our executive officers and the roles of our compensation and leadership development committee, or the compensation committee, and our board in the design and administration of these programs and policies, including specific compensation decisions in connection with our executive officers, including our named executive officers.

Our compensation committee has the sole authority and responsibility to review and determine, or recommend to the board for approval in the case of our Chief Executive Officer, the compensation of each of our named executive officers. Our compensation committee also considers the design and effectiveness of the compensation program for our executive officers and approves the final compensation package, employment agreements and equity-based compensation awards for all of our executive officers, except our Chief Executive Officer, whose compensation is approved by the board upon the recommendation of the compensation committee. Our compensation committee is composed entirely of independent directors who have never served as officers of the Company.

Set forth below is a discussion of the policies and decisions that shape our executive compensation program, including the specific objectives and elements. Information regarding director compensation is included under the heading “Director Compensation” below.

Executive Summary

Fiscal year 2022 was a transformational year for Aspen. The significant adoption of our PyroThin^® thermal barriers in the EV market, along with an improving energy infrastructure market, has propelled our Company forward in significant ways. During 2022 and more recently, we achieved several important business milestones, including the following:

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General Executive Compensation Philosophy and Principles

The objective of our executive compensation program is to attract, retain and motivate talented executives who are critical to our continued growth and success of building a profitable business, and to align the interests of these executives with those of our stockholders. To achieve this objective, besides annual base salaries, our executive compensation program utilizes a combination of annual incentives through cash bonuses based on a mix of pre-determined criteria and long-term incentives through equity-based compensation. In establishing overall executive compensation levels, our compensation committee considers a number of criteria, including the executive’s scope of responsibilities, prior and current period of performance, attainment of overall Company performance objectives and retention concerns. The overall compensation program is conceived to be generally competitive with the market median of peer companies with no specific percentile being targeted. The program combines the base salary with at-risk elements to achieve the Company’s mix of pay objectives.

2022 Executive Compensation Policies and Practices

During 2022, our executive compensation policies and practices included the following:

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The Role of Our Compensation Committee and Compensation Consultant

Generally, our compensation committee designs and administers the executive compensation program with the help of the management and an independent compensation consultant. In connection with the compensation of our Chief Executive Officer, our compensation committee further recommends the overall and specific elements to our board for consideration and final determination. While the compensation committee addresses the matters related to its responsibilities under its charter throughout the year, annual reviews and, as appropriate, modifications of compensation arrangements for executive officers typically take place during a period starting from the last quarter of the prior fiscal year through the first quarter of the current fiscal year.

While the compensation committee or the board, in the case of our Chief Executive Officer, ultimately makes all final decisions on executive compensation, the compensation committee engages the services of outside advisors for assistance. In 2020, 2021 and 2022, the compensation committee directly engaged Meridian Compensation Partners LLC (“Meridian”) as its independent compensation consultant. The compensation committee utilized Meridian throughout these periods to provide independent, objective research, analysis, and advice and to assist the compensation committee generally in the performance of its duties. The compensation committee will typically request information and recommendations directly from the compensation consultant as it deems appropriate to structure and evaluate our executive compensation program. During these periods, the compensation committee also enlisted the assistance of external legal counsel to advise concerning its compensation decisions through contracts and other written documents. The compensation committee assesses the independence of its compensation consultant and external legal counsel each year, considering the amount of fees paid to them, the policies designed to prevent conflicts of interest, any Company stock owned by the consultant or the law firm, and other factors that may be relevant to the compensation committee.

The compensation committee considers external market data when making compensation decisions concerning executive pay levels and program design. The committee has formally approved a peer group for this purpose (and also considers other market data sources as appropriate). The peer group was originally developed by Meridian out of a candidate pool of size (as measured principally by revenue and market capitalization) and industry-appropriate publicly-traded companies. Our compensation committee periodically reviews and, as appropriate, revises the peer group in coordination with input from our Chief Executive Officer and Meridian to ensure the group remains appropriate for the purposes of comparing executive compensation. As a basis for the source market data for setting executive compensation for fiscal year 2022, our peer group consisted of the following 17 companies:

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Additional information about the compensation committee’s executive compensation decisions for fiscal year 2023 will be provided in our proxy statement for the 2024 annual meeting of stockholders.

We believe our peer group provides useful information to help us establish competitive compensation practices and allows us to set compensation levels to attract, retain and motivate a talented executive team while aligning the interests of our executives with those of our stockholders. The group is subject to change over time, and we expect that the compensation committee will continue to periodically review and update the list.

Role of Management

In making compensation decisions, our compensation committee considers the recommendations of our Chief Executive Officer, Mr. Young, and our Senior Vice President, Human Resources, Ms. Conte, who work together to make recommendations to our compensation committee with respect to our executive officers, but do not participate in the deliberations or determination of their own compensations. Our compensation committee may review and approve the corporate objectives and goals pursuant to the powers delegated pursuant to its charter. Mr. Young annually leads the development of our corporate objectives and goals, which are reviewed and approved by the compensation committee and then our board. Mr. Young provided the Company’s business and operational perspective for our compensation committee’s final review of progress made on the goals set for 2022. Other than as described above, no other executive officer participates in the determination or recommendation of the amount or form of executive officer compensation.

Say-on-Pay Results

At our last annual meeting of stockholders in June 2022, we held a stockholder advisory vote on the fiscal year 2021 compensation of our named executive officers. This is generally referred to as a “Say-on-Pay” vote. Our stockholders approved the fiscal year 2021 compensation of our named executive officers with approximately 93% of stockholder votes cast in favor of our Say-on-Pay resolution. This stockholder feedback was considered in the compensation committee’s decisions on fiscal year 2022 compensation, discussed below. The compensation committee continues to monitor further stakeholder feedback, Company performance, and market developments for potential further improvements to the Company’s compensation structure for executive officers.

Main Elements of Our Executive Compensation Program

Base Salary

Annual base salaries compensate our executive officers for fulfilling the requirements of their respective positions and provide them with a level of cash income predictability and stability with respect to a portion of their total compensation. We believe that the level of an executive officer’s base salary should reflect the executive’s performance, experience and breadth of responsibilities, our understanding of salaries for similar positions within our industry and any other factors relevant to that particular job. Our salaries are designed to be generally competitive with the market median of our peer group.

Base salaries are typically negotiated at the outset of an executive’s employment. Salary levels are considered annually as part of our performance review process, but also in cases including promotion or other change in the job responsibilities of an executive officer. For named executive officers, initial base salaries generally are established in connection with negotiation of an offer of employment and employment agreement. Increases in base salary have several elements. In addition to promotion and increased responsibilities, merit and Company-wide general increases are also taken into consideration. Salaries of our named executive officers for fiscal years 2022, 2021 and 2020 are also reported in the Summary Compensation Table.

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The 2022 base salaries for our Named Executive Officers were as follows:

Cash Bonus Plan

Our employee cash bonus plan is designed to motivate and reward our executives for achieving certain corporate, financial and other business performance goals during the fiscal year, and the plan is administered by the compensation committee. The plan provides that executives are eligible to receive a cash bonus over an annual performance period based on goals established by the compensation committee, which may include revenue goals, an adjusted EBITDA goal and/or such other performance goals as may be established by the compensation committee from time to time. The compensation committee determines the percentage of annual base salary as target bonus opportunity for each executive. Each executive receives a bonus plan participation letter that sets forth, among other things, the minimum threshold achievement levels applicable to each goal. Following completion of the performance period, the administrator determines the level of performance achieved for each goal and approves the amount of the cash payments to be made. The maximum bonus that can be earned is limited to 225% of the target bonus. The compensation committee also reserves the right to pay discretionary bonuses to account for unanticipated, unusual or extraordinary circumstances or performance.

Upon the recommendation of our compensation committee, our board approved the target bonus amounts and goals under the bonus plan for fiscal year 2022 for the named executive officers. We do not disclose specific financial performance goals due to potential competitive harm. Each named executive officer’s 2022 bonus award amount, calculated as a percentage of year-end base salary, was based on achieving and exceeding certain performance metrics. For 2022, these performance metrics were revenue and adjusted EBITDA. Calculation of the achievement of the adjusted EBITDA target was made in a manner that excluded the impact of any costs incurred in 2022 associated with intellectual property enforcement litigation and certain other strategic activities, as determined by our board or compensation committee. For revenue and adjusted EBITDA, the 2022 performance metrics established, for each metric, a threshold value that must be achieved before any bonus amount would be paid out, a target value (the “Target”) associated with a target bonus amount, and an incentive amount if the Target is exceeded (up to the maximum potential award of 225% of the Target). In August 2022, the board approved management’s suggested updates to the Company’s 2022 annual operating plan, based on significant changes in the Company’s financial condition and the demand profile for the Company’s products that occurred throughout the year. Accordingly, the 2022 cash bonus plan goals for revenue and adjusted EBITDA performance were correspondingly revised, and bonus payouts were determined based on actual performance relative to the revised goals and restated annual operating plan.

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In addition, a component of the bonus (the Management by Objective Component, or “MBO Component”), expressed as a percentage, usually an additional 10% of each named executive officer’s target bonus, may be added to or deducted from an otherwise earned bonus based upon the relative achievement, or lack thereof, of certain additional strategic or operational performance goals, as determined by our board or compensation committee. The target bonus amounts for fiscal year 2022 for Messrs. Young, Rodriguez, Fairbanks, Whitaker, Landes and Schilling, expressed as a percentage of their year-end base salary, are presented below.

The actual bonuses varied depending on our percentage achievement of the Target set by the compensation committee.

On March 7, 2023, the compensation committee awarded bonus payments to the named executive officers other than the Chief Executive Officer, and on March 8, 2023, the board awarded a bonus payment to our Chief Executive Officer. The 2022 bonus payments under the cash bonus plan and the additional discretionary bonus payments are set forth below:

Long Term Equity Incentive Plan

Our board established the 2014 Employee, Director and Consultant Equity Incentive Plan (the “2014 Plan”), in 2014, prior to the Company’s initial public offering. Our board is the administrator of the 2014 Plan, as provided by our compensation committee charter. The compensation committee, based on its annual review of compensation levels for each of our executives, determines a dollar amount value of the annual equity grants. The compensation committee also determines the mix of equity instruments for equity grants issued pursuant to the 2014 Plan, such as options to purchase our common stock, restricted stock units (“RSUs”), or restricted stock awards, as well as a vesting schedule. For 2022, the mix for equity grants was set at 75% stock options and 25% RSUs for our named executive officers. Except in special circumstances, time-based vesting is used. The stock options and RSUs granted by the Company in recent years vest in equal installments on an annual basis during the three years following the grant. Pursuant to our 2014 Plan, the exercise price of the stock options is the closing price of our stock at the New York Stock Exchange on the grant date. Similar to other components of compensation, the compensation committee recommends the equity grants for our Chief Executive Officer to our board for approval.

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The equity awards granted to our named executive officers during 2022 were as follows:

Other Aspects of Executive Compensation

Benefits and Perquisites—In addition to the components described above, our executives are eligible to participate in other benefits available to all of our employees. These benefits include a 401(k) plan with a Company match element, healthcare insurance with a Company contribution to the premium, short-term and long-term disability insurance, term-life insurance, a dental plan and a vision plan. We generally do not provide perquisites or personal benefits to our named executive officers. However, we do pay a portion of the premiums for medical, dental, group term life, disability and accidental death and dismemberment insurance for all of our full-time employees.

Section 401(k) Plan—We maintain a defined contribution employee retirement plan, or the 401(k) Plan, for our employees. Our executive officers are eligible to participate in the 401(k) Plan on the same basis as our other employees. The 401(k) Plan is intended to qualify as a tax-qualified plan under Section 401(a) of the Code. The 401(k) Plan provides that each participant may contribute up to the lesser of 100% of their compensation or the statutory limit, which was $20,500 for calendar year 2022. Participants that are 50 years or older can also make “catch-up” contributions, which in calendar year 2022 may have been up to an additional $6,500 above the statutory limit. We currently make matching contributions into the 401(k) Plan on behalf of participants. We match 50% of eligible contributions up to the first 6% of eligible compensation. Participant contributions are held and invested, pursuant to the participant’s instructions, by the plan’s trustee.

Employment Contracts—We have entered into an executive employment agreement with our Chief Executive Officer, Mr. Young, effective January 1, 2022. We have also entered into executive employment agreements with Messrs. Rodriguez, Whitaker, Landes and Schilling.

Special Named Executive Officer Compensation Arrangements

In addition to the compensation elements discussed above, we have entered into certain special arrangements related to the compensation of our Chief Executive Officer and other named executed officers. In order to encourage ownership of shares, reward our named executive officers for their performance, retain our named executive officers, and encourage their alignment with our longer-term value and our shareholders, and to support the Company’s ambitious growth agenda requiring multiple new investments, strengthening relationships with new investors and strategic partners in the EV market and growing our executive team and employee base, the board, upon recommendation of the compensation committee, granted to Mr. Young 461,616 shares in 2021, and to each of Messrs. Rodriguez, Whitaker, Landes and Schilling, 53,590 shares in 2022, of performance-based restricted stock, pursuant to Performance-Based Restricted Stock Agreements by and between the Company and the named executed officers. Additional details of these awards are found under the section below, titled “Narrative Disclosure to Summary Compensation Table—Performance-Based Restricted Stock Awards.”

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Compensation Recoupment Policy

In December 2018, our board adopted a compensation recoupment policy, which applies to certain designated employees, including our named executive officers. The policy permits us to recoup incentive compensation paid to the designated employees in the event of an accounting restatement of any of the unaudited interim quarterly or audited annual consolidated financial statements of the Company due to significant non-compliance with financial reporting requirements under applicable laws, rules and regulations or upon certain forms of misconduct by a designated employee. As noted above, our compensation recoupment policy is currently under review in light of the proposed rule changes by the SEC and the NYSE, and we expect to timely promulgate an amended policy consistent with final rulemaking.

Prohibition on Hedging and Pledging

Our insider trading policy prohibits members of the board, the named executive officers, and all other employees from purchasing financial instruments designed to hedge the economic risk of owning our securities (or entering any transaction that has the same economic effect), and prohibits certain persons, including members of the board and the named executive officers, from pledging our securities.

Stock Ownership Guidelines

Our board established stock ownership guidelines for the executive officers and directors effective November 1, 2017, which provide target levels of stock ownership that executive officers and directors must attain. The target ownership level for our Chief Executive Officer is three-times the base salary; for our other executive officers, the target level is one-times their respective base salary; and for our non-employee directors, the target level is three-times the annual cash retainer for service to the board.

Risk Analysis of Our Compensation Plans

Company management assesses and discusses with the compensation committee of the board our compensation policies and practices for our employees as they relate to risk management. Based on this assessment, we do not believe that any risks arise from such policies and practices that are reasonably likely to have a material adverse effect on the Company now or in the future.

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COMPENSATION COMMITTEE REPORT*

Our compensation committee has reviewed and discussed the Compensation Discussion and Analysis required by Item 402(b) of Regulation S-K with management, and based on such review and discussion, our compensation committee recommended to our board that the Compensation Discussion and Analysis be included in this proxy statement.

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RISKS RELATED TO COMPENSATION PRACTICES AND POLICIES

Consistent with SEC disclosure requirements, we have assessed our compensation policies, practices and awards, and have concluded that our compensation policies, practices and awards do not create risks that are reasonably likely to have a material adverse effect on the Company. Our compensation committee assessed our compensation and benefits programs to determine if the programs’ provisions and operations create undesired or unintentional risk of a material nature. Our compensation programs include a combination of fixed base salaries, cash bonuses, long-term incentive awards, and benefits that are generally uniform in design and operation throughout the Company and with all levels of employees.

We also believe that our incentive compensation arrangements provide incentives that do not encourage risk-taking beyond the organization’s ability to effectively identify and manage significant risks, are compatible with our effective internal controls and our risk management practices, and are supported by the oversight and administration of the compensation committee and board with regard to executive compensation programs.

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EXECUTIVE AND DIRECTOR COMPENSATION

Summary Compensation Table

The following table shows the total compensation paid or accrued during the last three fiscal years ended December 31, 2022, 2021 and 2020 to (1) our President and Chief Executive Officer, (2) our Chief Financial Officer and Treasurer, (3) our former Chief Financial Officer and Treasurer, who served in that capacity during a portion of 2022, and (4) the next three most highly compensated executive officers who earned more than $100,000 during the respective fiscal year and were serving as executive officers as of year-end.

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Narrative Disclosure to Summary Compensation Table

Employment Arrangements with Our Named Executive Officers

Donald R. Young

Effective January 1, 2022, we entered into an executive agreement with Mr. Young with a three-year term, or the 2022 CEO Agreement. Pursuant to 2022 CEO Agreement, Mr. Young’s annual base salary was $515,000 per year and Mr. Young was eligible to receive an annual performance-based bonus as determined by our board with a target of 110% of his year-end base salary. Previously, in November 2018, we entered into an executive agreement with Mr. Young effective January 1, 2019 with a three-year term, or the 2018 CEO Agreement. Mr. Young serves as our Chief Executive Officer on an at-will basis. Pursuant to the 2018 CEO Agreement, Mr. Young’s annual base salary for fiscal year 2019 was set to $515,000 per year and Mr. Young was eligible to receive an annual performance-based bonus as determined by our board with a target of 100% of his year-end base salary. Mr. Young’s target bonus for each of fiscal 2020, 2021 and 2022 was set at 110% of his year-end base salary.

Mr. Young’s base salary may be increased, but not decreased without his consent, at the discretion of our board. On August 1, 2019, we entered into an amendment (the “Amendment”) to the 2018 CEO Agreement. Effective January 1, 2020, we amended the 2018 CEO Agreement to provide for at least a year of time to exercise all vested stock options in connection with termination of employment in certain circumstances under the 2018 CEO Agreement.

Mr. Young has also entered into a confidentiality and non-competition agreement. Among other things, this agreement obligates Mr. Young to refrain from disclosing any of our proprietary information received during the course of employment and to assign to us any inventions conceived or developed during the course of employment. Additionally, following termination of employment, Mr. Young is prohibited from (i) competing with us for a period of one year and (ii) soliciting or interfering with our business relationship with any of our existing clients, customers, business partners or employees for a period of two years.

Mr. Young is entitled to certain benefits in connection with a termination of his employment or a change of control as discussed below under “— Potential Payments Upon Termination or Change of Control.”

Other Named Executive Officers

Effective January 1, 2023, we entered into executive agreements with Messrs. Rodriguez, Whitaker, Landes and Schilling (the “2023 Executive Agreements”). Pursuant to the 2023 Executive Agreements, the annual base salaries effective as of April 1, 2023 of each of Messrs. Rodriguez, Whitaker, Landes and Schilling are $400,000, and they are each eligible to receive an annual bonus as determined by our board or a committee thereof with a target bonus of 55%, 55%, 55% and 50%, respectively, of their respective year-end base salaries. The 2023 Executive Agreements include an automatic renewal provision for each calendar year, unless either the Company or the executive provides written notice of non-renewal at least 60 days before the applicable annual expiration date, and also contain customary confidentiality, non-disclosure, non-competition, non-solicitation, non-recruitment, trade secrets, intellectual property ownership, and cooperation provisions.

Messrs. Rodriguez, Whitaker, Landes and Schilling are entitled to certain benefits in connection with a termination of their employment or a change of control as discussed below under “— Potential Payments Upon Termination or Change of Control.”

In January 1, 2022, we entered into executive agreements with Messrs. Fairbanks, Whitaker and Landes for a one-year term (the “2022 Executive Agreements”). Pursuant to the 2022 Executive Agreements, the annual base salaries of Messrs. Fairbanks, Whitaker and Landes for fiscal year 2022 were $300,005, $400,000 and $400,000, respectively and they were eligible to receive an annual bonus as determined by our board or a

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committee thereof with a target bonus of 55%, each, of their respective year-end base salaries. The 2022 Executive Agreements expired on December 31, 2022, except with respect to Mr. Fairbanks, whose agreement terminated effective April 1, 2022. See below – Separation Arrangements with Mr. Fairbanks.

Separation Arrangements with Mr. Fairbanks

On March 29, 2022, Mr. Fairbanks, the former Chief Financial Officer and Treasurer of the Company, entered into a Separation Agreement and Release with the Company (the “Separation Agreement”), effective as of April 1, 2022 (the “Transition Date”). Effective as of the Transition Date, Mr. Fairbanks transitioned to providing consulting and advisory services to the Company for a period ending on March 31, 2023 (the “Consulting Period”) pursuant to a Consulting Agreement and incorporated Statement of Work, dated as of March 29, 2022, by and between Mr. Fairbanks and the Company (the “Consulting Agreement”). Mr. Fairbanks retired and resigned from his position as Chief Financial Officer and Treasurer of the Company effective as of the Transition Date. Pursuant to the terms of the Separation Agreement, in consideration for, among other things, his compliance with certain restrictive covenants, including customary non-competition and non-solicitation covenants, and a typical release of claims, Mr. Fairbanks is permitted to exercise any vested options held by Mr. Fairbanks until the later of (i) one year from the Transition Date or (ii) one year from the date on which Mr. Fairbanks ceases to provide services under the Consulting Agreement, but in no event beyond April 1, 2024. Furthermore, pursuant to the terms of the Consulting Agreement, any previously granted unvested equity awards will continue to vest through the Consulting Period, subject to Mr. Fairbanks continuing to provide consulting and advisory services to the Company through each such vesting date.

2022 Time-Based Equity Awards

On February 23, 2022, Messrs. Young, Fairbanks, Rodriguez, Whitaker, Landes and Schilling were each granted stock options and RSUs. Specifically, Mr. Young was granted an option to purchase 49,795 shares of our common stock at an exercise price of $26.29 per share and 9,509 RSUs. Mr. Fairbanks was granted an option to purchase 14,938 shares of our common stock at an exercise price of $26.29 per share and 2,852 RSUs, Mr. Rodriguez was granted an option to purchase 13,693 shares of our common stock at an exercise price of $26.29 and 2,615 RSUs. Mr. Whitaker was granted an option to purchase 22,408 shares of our common stock at an exercise price of $26.29 per share and 4,279 RSUs, Mr. Landes was granted an option to purchase 22,408 shares of our common stock at an exercise price of $26.29 per share and 4,279 RSUs, and Mr. Schilling was granted an option to purchase 22,408 shares of our common stock at an exercise price of $26.29 per share and 4,279 RSUs. The stock options and RSUs vest in equal annual installments over a three-year period from the date of grant, subject to the recipient continuing to provide services to the Company through each vesting date.

On February 25, 2022, Mr. Rodriguez was granted an option to purchase 7,762 shares of our common stock at an exercise price of $29.51 and 1,482 RSUs. The stock options and RSUs vest in equal annual installments over a three-year period from the date of grant, subject to the recipient continuing to provide services to the Company through each vesting date.

Performance-Based Equity Awards Modifications to 2015 Special Equity Incentive Grants

On December 11, 2015, our board granted to Mr. Young, (i) 78,125 shares of restricted common stock which vest based on the achievement of a Company performance target for fiscal year 2020 (the “SEIG Restricted Shares”), (ii) a nonqualified stock option to purchase 84,745 shares of common stock which vest in full on the third anniversary of the grant date (the “SEIG Time-Based Option”); and (iii) a nonqualified stock option to purchase 370,181 shares of common stock, which vest in multiple tranches upon the achievement of certain milestones (the “SEIG Performance Option”). The SEIG Time-Based Option and the SEIG Performance Option were granted with an exercise price equal to $6.40, which was above the fair market value of our common stock on the date of grant and was equal to the 30 day VWAP on the grant date. The stock options would vest provided Mr. Young continued to provide services to the Company on the applicable vesting date. On December 10, 2020, our board extended the performance period of certain of the SEIG Performance Option

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through December 18, 2020. The SEIG Performance Options with respect to 238,603 shares met the specified criteria and vested on December 11, 2020 and December 18, 2020, respectively. The remainder of the SEIG Performance Options and the SEIG Restricted Shares failed to vest and were forfeited due to the performance criteria not having been met. Accordingly, as of December 31, 2020, all components of the 2015 SEIG awards were either earned and thus vested or forfeited.

Performance-Based Restricted Stock Awards

Chief Executive Officer

On June 29, 2021, as recommended by the compensation committee, the board granted to Mr. Young 461,616 shares of performance-based restricted stock, pursuant to a Performance-Based Restricted Stock Agreement by and between us and Mr. Young (the “CEO Performance Agreement”).

In order for a tranche of this award to vest, both time and performance vesting conditions must be satisfied. For the time vesting condition, a tranche will vest at the later of (i) three years from the grant date or (ii) one year from the date when an applicable performance hurdle is achieved, subject to a maximum five-year vesting period for shares with respect to which the performance hurdle has been achieved. With respect to the performance vesting condition, as noted in the table below, there are three tranches with different share price hurdles and a five-year total performance period. The hurdles reflect share prices of 2X, 3X, and 4X of the baseline price that was established at the time of the award, which is $21.663. If a share price hurdle is not met after five years, the applicable tranche is forfeited. The share price hurdle is met by reference to a 30-day volume weighted average price, or the VWAP, that is maintained for 60 days. In the event of a Change of Control Sale of the Company, as defined in the CEO Performance Agreement, the share price hurdle is valued based on the per share value received by our shareholders, with cash consideration valued at par, any publicly traded securities received as consideration valued at their 60-day VWAP as of the closing date of the Change of Control Sale of the Company, and any securities that are not publicly traded or for which a 60-day VWAP cannot be valued by the board. Any of the tranches below could be earned at any point over the five-year period.

In the event of a Change of Control Sale of the Company, a portion, capped at 100%, of the next unearned tranche would be earned in proportion to the excess of the Change of Control Sale of the Company price above $21.663, and any unearned tranches would be forfeited. The calculation of the earned portion of the next unearned tranche would be based on the following formula:

In the event of a Change of Control Sale of the Company, any earned shares would continue to be subject to the time-based vesting condition, provided, however, that if the successor company in the Change of Control Sale of the Company did not assume our obligations under the CEO Performance Agreement, all earned shares would become vested as of immediately prior to the closing of the Change of Control Sale of the Company.

In the event we terminate Mr. Young’s service as our employee, director, or consultant for Cause, as defined in Mr. Young’s employment agreement with us, as amended, or if the board determines, within one year after Mr. Young is terminated, that either prior or subsequent to Mr. Young’s termination that he engaged in conduct

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that would constitute Cause, or if Mr. Young resigns without Good Reason, as defined in his employment agreement, all shares granted pursuant to this award that remain unvested will be forfeited to the Company immediately as of the time Mr. Young is notified that he has been terminated for Cause, that he engaged in conduct that would constitute Cause, or as of the effective time of Mr. Young’s resignation without Good Reason.

In the event we terminate Mr. Young without Cause or Mr. Young resigns for Good Reason, or in the event of Mr. Young’s death or disability, all earned shares for which the performance vesting condition has been met and which are subject to the continued time vesting condition will vest. Further, in the event we terminate Mr. Young without Cause or Mr. Young resigns for Good Reason, a pro rata fraction, capped at 100%, of the next unearned tranche will be earned and vest based on the following formula. Any other unearned tranches will be forfeited.

Otherwise, in the event Mr. Young is no longer our employee, director, or consultant or an affiliate prior to the achievement of a performance goal listed above, or we do not achieve a performance goal by the fifth anniversary of the grant date, Mr. Young will immediately forfeit to us the number of shares granted that have not yet vested pursuant to the table above.

Non-CEO Named Executive Officers

On June 2, 2022, as recommended by the compensation committee, the board granted to each of Messrs. Rodriguez, Whitaker, Landes and Schilling 53,590 shares of performance-based restricted stock, pursuant to a Performance-Based Restricted Stock Agreement by and between us and each of the executives (the “Executives’ Performance Agreements”).

In order for a tranche of this award to vest, both time and performance vesting conditions must be satisfied. For the time vesting condition, a tranche will vest at the later of (i) three years from the grant date or (ii) one year from the date when an applicable performance hurdle is achieved, subject to a maximum five-year vesting period for shares with respect to which the performance hurdle has been achieved. With respect to the performance vesting condition, as noted in the table below, there are three tranches with different share price hurdles and a five-year total performance period. If a share price hurdle is not met after five years, the applicable tranche is forfeited. The share price hurdle is met by reference to a 30-day volume weighted average price, or the VWAP, that is maintained for 60 days. In the event of a Change of Control Sale of the Company, as defined in the Executives’ Performance Agreements, the share price hurdle is valued based on the per share value received by our shareholders, with cash consideration valued at par, any publicly traded securities received as consideration valued at their 60-day VWAP as of the closing date of the Change of Control Sale of the Company, and any securities that are not publicly traded or for which a 60-day VWAP cannot be valued by the Board. Any of the tranches below could be earned at any point over the five-year period.

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In the event of a Change of Control Sale of the Company, a portion, capped at 100%, of the next unearned tranche would be earned in proportion to the excess of the Change of Control Sale of the Company price above $18.66, and any unearned tranches would be forfeited. The calculation of the earned portion of the next unearned tranche would be based on the following formula:

In the event of a Change of Control Sale of the Company, any earned shares would continue to be subject to the time-based vesting condition, provided, however, that if the successor company in the Change of Control Sale of the Company did not assume our obligations under the Executives’ Performance Agreements, all earned shares would become vested as of immediately prior to the closing of the Change of Control Sale of the Company.

In the event we terminate an executive’s service as our employee, director, or consultant for Cause, as defined in the executive’s employment agreement with us or if the board determines, within one year after the executive is terminated, that either prior or subsequent to the executive’s termination that the executive engaged in conduct that would constitute Cause, or if the executive resigns without Good Reason, as defined in the executive’s employment agreement, all shares granted pursuant to this award that remain unvested will be forfeited to us immediately as of the time the executive is notified that the executive has been terminated for Cause, that the executive engaged in conduct that would constitute Cause, or as of the effective time of the executive’s resignation without Good Reason.

In the event we terminate an executive without Cause or an executive resigns for Good Reason, or in the event of an executive’s death or disability, all earned shares for which the performance vesting condition has been met and which are subject to the continued time vesting condition will vest. Further, in the event we terminate an executive without Cause or the executive resigns for Good Reason, a pro rata fraction, capped at 100%, of the next unearned tranche will be earned and vest based on the following formula. Any other unearned tranches will be forfeited.

Otherwise, in the event an executive is no longer our employee, director, or consultant or an affiliate prior to the achievement of a performance goal listed above, or we do not achieve a performance goal by the fifth anniversary of the grant date, the executive will immediately forfeit to us the number of shares granted that have not yet vested pursuant to the table above.

Cash Bonus Plan

Upon the recommendation of our compensation committee, our board initially approved our employee cash bonus plan in April 2012. The plan is administered by the compensation committee. The plan provides that

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participants are eligible to receive a cash bonus over an annual performance period based on goals established by the administrator, which may include attaining revenue goals, an adjusted EBITDA goal, an individual goal and/or such other performance goals as may be established by the administrator from time to time. Each participant receives a participant letter setting forth, among other things, a percentage allocation of a target award based upon a percentage of base salary or set forth as a dollar amount. The participation letters also set forth minimum threshold achievement levels applicable to each goal. Following completion of the performance period, the administrator determines the level of performance achieved for each goal and approves the amount of the cash payments to be made.

2020 Bonus Plan and Payments

Upon the recommendation of our compensation committee, our board approved the target bonus amounts and goals under the bonus plan for fiscal year 2020 for Mr. Young on December 11, 2019. Our compensation committee approved the target bonus amounts and goals under the bonus plan for fiscal year 2020 for Messrs. Fairbanks, Whitaker and Landes on December 11, 2019. Each named executive officer’s 2020 bonus award amount, calculated as a percentage of year-end base salary, was based on achieving and exceeding certain performance metrics. For 2020, these performance metrics were revenue and adjusted EBITDA. Calculation of the achievement of the adjusted EBITDA target was made in a manner that excluded the impact of any costs incurred in 2020 associated with intellectual property enforcement litigation and certain other strategic activities, if so determined by our board or compensation committee. For revenue and adjusted EBITDA, the 2020 performance metrics specified a threshold value that must be achieved before any bonus amount was to be paid under that metric, a target value associated with a target bonus amount, and an incentive amount if the target value was exceeded. In addition, a component of the bonus, expressed as a percentage of the target bonus amount, was to be added to or deducted from otherwise earned bonus based upon the relative achievement, or lack thereof, of certain additional performance goals, as determined by our board or our compensation committee, or the 2020 MBO Component. The target bonus amounts for fiscal year 2020 for Messrs. Young, Fairbanks, Whitaker and Landes expressed as a percentage of their year-end base salary, were 110%, 55% and 55%, respectively. The maximum bonus that could have been earned was limited to 225% of the target bonus. The performance metrics were not achieved during fiscal year 2020 and no payouts were made to the named executive officers under the 2020 bonus plan. In addition, the named executive officers consented to the termination of the 2020 MBO Component of the 2020 bonus plan, and therefore no bonus payouts were made in connection with the 2020 bonus plan.

2021 Bonus Plan and Payments

Upon the recommendation of our compensation committee, our board approved the target bonus amounts and goals under the bonus plan for fiscal year 2021 for Mr. Young on February 24, 2021. Our compensation committee approved the target bonus amounts and goals under the bonus plan for fiscal year 2021 for Messrs. Fairbanks, Whitaker and Landes on February 23, 2021. Each named executive officer’s 2021 bonus award amount, calculated as a percentage of year-end base salary, was based on achieving and exceeding certain performance metrics. For 2021, these performance metrics were annual revenue and adjusted EBITDA. Calculation of the achievement of the adjusted EBITDA target was made in a manner that excluded the impact of any costs incurred in 2021 associated with intellectual property enforcement litigation and certain other strategic activities, if so determined by our board or compensation committee. For revenue and adjusted EBITDA, the 2021 performance metrics specify a threshold value, or the Target, that must be achieved before any bonus amount will be paid under that metric, a target value associated with a target bonus amount, and an incentive amount if the target value is exceeded. In addition, a component of the bonus, expressed as a percentage of the target bonus amount, could be added to or deducted from otherwise earned bonus based upon the relative achievement, or lack thereof, of certain additional performance goals, as determined by our board or our compensation committee. The Company did not fully achieve the Target required for a 100% target bonus payout. Based on the achievement formula, the executives were entitled to 70% of their target bonus. The compensation committee reserves the right to pay discretionary bonuses for fiscal year 2021 to account for

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unanticipated, unusual or extraordinary circumstances or performance. On February 23, 2022, the compensation committee, and with respect to the Chief Executive Officer, the board awarded bonus payments to the named executive officers as well as an additional discretionary amount, such that each named executive officer received the same total bonus amount as he or she would have received had 100% of the Target been achieved. The compensation committee and the board made this decision to award the additional discretionary amounts after thorough analysis and discussion of the Company’s fiscal 2021 financial performance, the reasons why the Target was not achieved including but not limited to, the Company’s decision, in consultation with the board, to allocate resources strategically to the emerging EV thermal barrier business that is expected to benefit the Company’s performance in the future, as well as COVID-19 related disruptions and supply chain disruptions, and a recognition of the level of performance throughout the year. When establishing the Target for 2021, the compensation committee did not anticipate the additional expenditure and resources that would be allocated to the EV thermal barrier business or the COVID-related disruptions to its business. In light of these circumstances and the compensation committee’s and the board’s assessments of the Company’s opportunity that was created in the EV market, the compensation committee and the board believed it was appropriate to pay the additional discretionary bonuses to reward and incentivize management. The compensation committee and the board believed that doing so was also consistent with the policy of aligning the interests of the Company’s employees with the interests of its stockholders. Based on the 2021 performance, Messrs. Young, Fairbanks, Whitaker and Landes received bonus payments of $617,485, $181,503, $242,000 and $242,000, respectively, which included discretionary bonus payments of $169,950, $49,501, $66,000 and $66,000, respectively.

2022 Bonus Plan and Payments

Upon the recommendation of our compensation committee, our board approved the target bonus amounts and goals under the bonus plan for fiscal year 2022 for the named executive officers. Each named executive officer’s 2022 bonus award amount, calculated as a percentage of year-end base salary, was based on achieving and exceeding certain performance metrics. For 2022, these performance metrics were revenue and adjusted EBITDA. Calculation of the achievement of the adjusted EBITDA target was made in a manner that excluded the impact of any costs incurred in 2022 associated with intellectual property enforcement litigation and certain other strategic activities, if so determined by our board or compensation committee. In 2022, the board approved management’s proposed revisions to the annual operating plan mid-year, based on material changes in business circumstances and in the demand profile for our output. Accordingly, the 2022 cash bonus plan goals for revenue and adjusted EBITDA performance were also revised, and bonus payouts were determined based on actual performance relative to the revised goals. For revenue and adjusted EBITDA, the 2022 performance metrics specified a threshold value that must be achieved before any bonus amount was to be paid under that metric, a target value associated with a target bonus amount, and an incentive amount if the target value was exceeded. In addition, a component of the bonus, expressed as a percentage of the target bonus amount, was to be added to or deducted from otherwise earned bonus based upon the relative achievement, or lack thereof, of certain additional performance goals, as determined by our board or our compensation committee, or the 2022 MBO. The target bonus amounts for fiscal year 2022 for Messrs. Young, Rodriguez, Fairbanks, Whitaker, Landes and Schilling expressed as a percentage of their year-end base salary, were 110%, 50%, 55%, 55%, 55% and 50%, respectively. The maximum bonus that could have been earned was limited to 225% of the target bonus. As a result of achieving and exceeding the 2022 performance thresholds, our compensation committee recommended and our board approved, as necessary, bonus payments for fiscal year 2022 under our cash bonus plan to Messrs., Young, Rodriguez, Whitaker, Landes and Schilling of $804,011, $249,246, $313,338, $313,338 and $283,852, respectively. Mr. Fairbanks did not receive a bonus for fiscal year 2022 because he was no longer employed by the Company.

2023 Conditional Equity Awards

As a result of factors such as the volatility of the Company’s stock price and market conditions in recent years, the share reserve under the 2014 Plan has been utilized more rapidly than we had expected. Accordingly, due to the lack of sufficient shares available under the 2014 Plan to fully fund the annual equity awards for our

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regular 2023 grant cycle, in March 2023, the compensation committee (or, in the case of awards to our Chief Executive Officer, the board) approved the grant of stock options and restricted stock units under the proposed 2023 Plan (as defined below) to our executive officers and certain other key employees (the “executive team”), with those grants to be effective on the date of approval of the 2023 Plan by our stockholders at the Annual Meeting, but only to the extent the 2023 Plan is approved by the Company’s stockholders. We refer to such awards as “Conditional Awards.” If the 2023 Plan is approved by stockholders, the Conditional Awards will be granted 75% by value as stock options, and 25% by value as RSUs. This mix of vehicles is the same as the Company’s historical long-term incentive mix for the last several years and reflects the compensation committee’s view that the best measure of the Company’s long-term performance is the appreciation of the stock price. See “Approval of the Aspen Aerogels, Inc. 2023 Equity Incentive Plan” for additional information. The table below provides more information regarding the total dollar value of Conditional Awards that will be granted to each of the named executive officers under the 2023 Plan if stockholders approve the 2023 Plan.

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2022 Fiscal Year Grants of Plan-Based Awards

The following table sets forth information relating to the grant of plan-based incentive awards to our named executive officers in 2022.

Outstanding Equity Awards at 2022 Fiscal Year-End

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