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Exhibit 99.1 Aspen Aerogels , Inc. Reports Second Quarter 2021 Financial Results and Recent Business Developments NORTHBOROUGH , Mass . , July 29 , 2021 - Aspen Aerogels , Inc. ( NYSE : ASPN ) ( " Aspen " ) today announced financial results for the second quarter and first half of 2021 , which ended June 30 , 2021 , and discussed recent business developments . Total revenue for the second quarter was $ 31.7 million compared to $ 24.6 million in the second quarter last year . Second quarter net loss was $ 6.7 million compared to a net loss of $ 5.7 million in the second quarter of 2020. Net loss per share for the second quarter was $ 0.23 compared to $ 0.21 in the second quarter last year . Total revenue for the first half of 2021 was $ 59.8 million compared to $ 53.1 million in the first half last year . Net loss for the first half of 2021 was $ 12.9 million compared to a net loss of $ 8.9 million in the first half of 2020. Net loss per share for the first half the year was $ 0.46 in 2021 and $ 0.34 in 2020 . Adjusted EBITDA for the second quarter was $ ( 3.4 ) million compared to $ ( 2.1 ) million in the second quarter of 2020. Adjusted EBITDA for the first half was $ ( 6.0 ) million compared to $ ( 1.6 ) million in the first half of 2020. A reconciliation of non - GAAP Adjusted EBITDA to net loss is provided in the financial schedules that are part of this press release . An explanation of this non - GAAP financial measure is also included below under the heading “ Non - GAAP Financial Measures . " Second Quarter Highlights and Recent Business Developments • Total revenue grew 29 % to $ 31.7 million • Gross profit grew 61 % year - over - year to $ 4.6 million Won additional PyroThinTM scope with existing U.S. automotive customer Closed $ 75.0 million private placement with Koch Strategic Platforms Ended second quarter with cash of $ 102.3 million " Second quarter revenue growth of 29 % was driven by the beginning phase of the post - COVID recovery in our maintenance related business in the global petrochemical and refinery markets , solid growth in our European green building business and continued shipments to the Arctic LNG project . As a result of this strong growth , we experienced improvement in gross profit and gross margin versus the second quarter of 2020. During the quarter , we also increased investment in personnel , infrastructure and related activities to support our PyroThin ™ thermal barrier and battery materials businesses . These planned investments contributed to a decrease in Adjusted EBITDA and an increase in net loss versus 2020 , " stated Don Young , President and CEO of Aspen . " We continue to make strong progress in developing our PyroThin ™ thermal barrier business . During the second quarter , we won additional scope for PyroThinTM thermal barriers in the battery platform of our major U.S. automotive customer . Based on this customer's forecasts , we project that the cumulative revenue potential through 2030 from this customer has grown by 30 % to $ 1.3 billion . In addition , we are on the cusp of an important design win with a leading Asian automotive OEM . , " continued Mr. Young . " We are focused on securing additional design wins for PyroThin ™ thermal barriers as we strive to become the EV industry standard for the management of thermal runaway . " " In addition , Aspen Battery Materials ( ABM ) is deploying a three - pronged strategy to develop and commercialize our carbon aerogel battery materials . First , ABM is ramping capacity to meet 2021 demand from prospective battery and EV development partners for evaluation samples of our silicon - rich anode materials . Second , ABM is exploring the use of our patented carbon aerogels as a host scaffolding for the silicon programs of other companies . And , third , ABM has expanded the scope of its efforts with two prospective customers to include the exploration of the use of our carbon nanomaterials in solid state battery applications , " said Mr. Young . " On June 30 , 2021 , we successfully closed our $ 75.0 million private placement with an affiliate of Koch Strategic Platforms ( KSP ) . With KSP's investment , we now have the financial resources to demonstrate to prospective EV manufacturers that Aspen will be an outstanding long - term partner and supplier . These funds will also allow us to remain aggressive in making strategic investments including the construction of a second manufacturing facility . We are currently completing site selection , engaged in facility design and engineering and are preparing to purchase long lead - time equipment and initiate construction of the plant , ” concluded Mr. Young .