Why Use Silica Aerogels and Silica Gels in Aerospace Applications?

By Ibtisam AbbasiReviewed by Louis CastelJul 8 2026

Understanding Silica Aerogels and Silica Gels
Why Spacecraft Depend on Silica Aerogels
How Silica Aerogels Are Used in Space Missions
Companies Driving Aerogel Innovation
Why Aerogels Outperform Conventional Insulation
Current Challenges Facing Silica Aerogels
Recent Advances in Aerogel Technology
The Future of Aerogels in Space Exploration
Further Reading

Aerospace vehicles, particularly those designed for supersonic and hypersonic travel as well as space exploration, are exposed to extremely high temperatures. To manage these thermal conditions effectively, silica-based materials such as silica aerogels and silica gels are widely used. Silica gels are highly effective for moisture control, while silica aerogels are lightweight solids composed of more than 90% air, offering exceptional thermal insulation. Their high porosity and low density make them well suited for thermal management and weight reduction in aerospace systems. As a result, they are increasingly being used in ultrahigh-speed vehicles, next-generation spacecraft, satellites, and rovers.

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Understanding Silica Aerogels and Silica Gels

Nano-porous silica-based materials, with their exceptionally low thermal conductivity, low dielectric constant, and low surface energy, along with superior surface area and higher contact angle compared to conventional materials, have become a preferred choice for thermal regulation, optical, and microelectronic applications.¹

Silica gels, the most common type of silica nano-porous material, are used as desiccants and adsorbents for moisture control.² Silica aerogel, on the other hand, comprising almost 95% air, with a smaller size of mesopores, is a structurally insulating material.³

In addition to the thermal insulation and surface area attributes, the choice of raw material, synthesis process, and drying methods can impart optical transparency to these critical materials. Transparent, highly porous sol-gel materials with high visible light transparency minimize the scattering of incident light, making them essential for specialized applications such as transparent super-insulated windows in spacecraft, solar energy collectors in rovers and satellites, and Cherenkov radiators used in particle physics research.⁴

Why Spacecraft Depend on Silica Aerogels

Objects and equipment in space undergo extreme temperature fluctuations, with temperature changing rapidly from -220  to -270 , depending on the solar irradiance. Such extreme temperature swings lead to instrument damage, noise, and thermal cycling damage to the mechanical structures.⁵ Furthermore, the perfect vacuum with near-absence of air leads to no convective heat transfer, making Thermal Management Systems (TMS) and Thermal Protection Systems (TPS) integrated with insulation materials like silica aerogels a necessity.

The ultralight and translucent aerogels, made of gas, are perfect for thermal insulation in aerospace applications.⁶ They are also extremely lightweight, significantly reducing the vehicle’s gross weight, reducing fuel consumption and drag, and can also efficiently absorb, reflect, and scatter infrared radiation.⁷

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How Silica Aerogels Are Used in Space Missions

Aerogels have become an integral material in aerospace applications, with NASA using them to provide thermal insulation for its Mars rovers. Often referred to as "frozen smoke," these ultra-lightweight materials were incorporated into the thermal management system (TMS) of the Pathfinder mission, where they insulated the Sojourner rover and protected its equipment from malfunctioning during the extremely cold Martian nights.⁸ The Perseverance rover also incorporates ultra-lightweight aerogel insulation to maintain the required operating temperature within its electronics compartment, reducing the power required for thermal management and improving overall energy efficiency.

NASA has also used aerogels for maintaining cryogenic temperatures of rocket fuels, while working with industrial experts to develop the first flexible aerogel blanket in the 1990s.⁹ In recent years, aerogels have been key to developing the Multi-Layer Aerogel Insulation (MLAI) system, essential for the efficient functioning of active and passive cryogenic fluid management (CFM) in NASA spacecraft. Its lightweight nature, ease of integration, and excellent thermo-mechanical performance make it a significant improvement over the traditional multi-layer insulation (MLI) spacer materials used in previous missions. The novel material is well suited for a wide range of cryogenic applications, including cryogenic storage tanks and transfer lines for liquefied natural gas (LNG).¹⁰

Aerogels were also key in the Stardust mission in the 2000s, capturing dust samples from the comet and returning the specimens to Earth for detailed analysis. Silica aerogel has been used for hypervelocity particle capture by NASA, proving to be an excellent capture medium, allowing for full recovery of analyzable projectile residues.¹¹

Companies Driving Aerogel Innovation

Several companies are working constantly to develop sustainable, highly flexible aerogels, removing the barriers in commercial space flights. Aspen Aerogel is a leading player in the industry, having collaborated with NASA on multiple projects to provide advanced thermal insulation, maintain optimal operating temperatures, and protect critical instruments from thermal damage. The MLAI system for modern NASA missions has also been developed by Aspen Aerogels, who are the leader in industrial insulation aerogel blanket manufacturing, with popular products like Pyrogel^® industrial insulation.¹²

Cabot Corporation is another frontrunner in industrial-grade aerogel particles, with their ENTERA^® aerogel particle additives easily integrated into blankets, sheets, films, and coatings.¹³

Aerogel Technologies, LLC stands out as the top manufacturer of monolithic and mechanically strong aerogels. They have developed Airloy^® Ultramaterials aerogel, 15 times lighter than composites; yet, with 50% better insulation and 1000 times better soundproofing attributes. Aerogel has been collaborating with NASA Glenn Research Center for the last decade to provide innovation and commercialize modern aerogel technology.¹⁴

While organizations like NASA and the European Space Agency (ESA) are constantly researching modern and better aerogels and collaborating with companies, the high cost of aerogel manufacturing is a big hurdle. The partnerships between private companies and space agencies are the only possible way for scaling the manufacturing and production of aerogels while balancing the cost and performance issues.

Why Aerogels Outperform Conventional Insulation

Traditionally, materials like fiberglass were utilized for insulation applications. However, aerogels have proven to be a much more viable option as they ensure weight and cost savings for aerospace applications. The thermal conductivity of silica aerogels (around 0.01 to 0.02 ) is much lower than fiberglass (0.03 – 0.045 ), with silica aerogels providing superior thermal insulation in much thinner layers, while traditional materials require heavy insulating layers. Furthermore, silica aerogels have a much higher melting point (1,200  ), in comparison to fiberglass (760  ), enabling them to withstand much higher temperatures.

Current Challenges Facing Silica Aerogels

Aerogels have been quite revolutionary; however, traditional silica aerogels are extremely brittle like glass, with catastrophic fracture occurring under tensile loads.¹⁵ Another major problem with aerogels is the pretty high manufacturing cost, especially when special supercritical drying methods are employed.¹⁶ Scaling aerogels for large structures has also been a major problem, along with damage due to extreme vibrational stresses associated with the launch of space vehicles.

Recent Advances in Aerogel Technology

Experts have performed extensive research to overcome traditional limitations of aerogel material. Utilizing innovative materials and fabrication techniques like the freeze-drying fabrication method and phase separation, flexible polymers have been developed, which have improved mechanical attributes along with enhanced thermal insulation.¹⁷

Additive manufacturing or 3D printing techniques have been adopted to ensure a reduction in manufacturing costs. 3D printed polyimide/silica composite aerogel has been developed with outstanding shape memory and unmatched intelligent thermal insulation.¹⁸ The composite and hybrid materials developed by combining aerogels with specific fibers or polymers have been revolutionary, ensuring superior performance and durability.

The Future of Aerogels in Space Exploration

Aerogels are becoming a popular choice when it comes to space exploration missions. Experts believe that a geodesic dome shield composed of Kevlar and silica aerogel could be the best choice to provide shelter to the first human colony on Mars.¹⁹ Additionally, silica aerogels are the prime candidate for building specialized insulated greenhouses on Mars to trap heat, necessary for survival.

Silica aerogels are already being optimized to ensure unmatched radiation shielding and allow easy integration with spacecraft systems. The unique attributes offered by these materials have made them critical, as deep space exploration probes and rovers can’t survive without aerogels, which protect all the electro-mechanical equipment on board. With companies continuing to invest heavily in aerogel technology, the material is expected to play an increasingly important role in future deep-space aerospace missions, driven by its exceptional thermal insulation, lightweight nature, and overall performance.

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Further Reading

1. Wu, G., Wang, J., Shen, J., Yang, T., Zhang, Q., Zhou, B., Deng, Z., Fan, B., Zhou, D. and Zhang, F. (2001). A new method to control nano-porous structure of sol-gel-derived silica films and their properties. Materials Research Bulletin. 36(12). 2127–2139. DOI: doi.org/10.1016/s0025-5408(01)00691-2 https://www.sciencedirect.com/science/article/abs/pii/S0025540801006912
2. Bharath Gandu, A. Gangagni Rao and Cahan, R. (2021). Air pollution control by using different types of techniques and sorbents. Elsevier eBooks. Chapter 22. 978-0-12-820042-1. 575–594. DOI: doi.org/10.1016/b978-0-12-820042-1.00002-x.
   https://www.sciencedirect.com/science/chapter/edited-volume/abs/pii/B978012820042100002X
3. Lei, J., Zheng, S., Han, Z., Niu, Y., Pan, D., Liu, H., Liu, C. and Shen, C. (2024). A Brief Review on the Preparation and Application of Silica Aerogel. Engineered Science. DOI: doi.org/10.30919/es1214. https://www.espublisher.com/journals/articledetails/1214
4. Xie, J., Wang, L., Li, G., Liao, J. and Zhang, X. (2024). Transparent Silica Aerogels: Optical and Chemical Design, Controlled Synthesis, and Emerging Applications. Chemistry - An Asian Journal. DOI: doi.org/10.1002/asia.202400492. https://aces.onlinelibrary.wiley.com/doi/abs/10.1002/asia.202400492
5. Dong, K., Tseng, D., Li, J., Warkander, S., Yao, J. and Wu, J. (2022). Reducing temperature swing of space objects with temperature-adaptive solar or radiative coating. Cell Reports Physical Science, 3(10), p.101066. DOI: doi.org/10.1016/j.xcrp.2022.101066. https://www.sciencedirect.com/science/article/pii/S2666386422003605
6. NASA (2011). Aerogels: Thinner, Lighter, Stronger - NASA. [online] NASA. Available at: https://www.nasa.gov/aeronautics/aerogels-thinner-lighter-stronger/. [Accessed on: April 20, 2026].
7. Jin, R., Zhou, Z., Liu, J., Shi, B., Zhou, N., Wang, X., Jia, X., Guo, D. and Xu, B. (2023). Aerogels for Thermal Protection and Their Application in Aerospace. Gels. 9(8). 606. DOI: doi.org/10.3390/gels9080606. https://www.mdpi.com/2310-2861/9/8/606
8. NASA. (2020). Frozen Smoke | NASA Spinoff. [online] Available at: https://spinoff.nasa.gov/spinoff1998/ip3.htm. [Accessed on: April 21, 2026].
9. Borella, L., Rozo, A., Perfetti, C. and Carlo Saverio Iorio (2023). Characterization of Composite Freeze-Dried Aerogels with Simulant Lunar Regolith for Space Applications. Materials. 16(17). 5797–5797. DOI: doi.org/10.3390/ma16175797. https://www.mdpi.com/1996-1944/16/17/5797
10. Nasa.gov. (2025). Thin Aerogel as a Spacer in Multi-Layer Insulation for Cryogenic Space Applications. Small Business Innovation Research/Small Business Tech Transfer. NASA TechPort. [online] Available at: https://techport.nasa.gov/projects/9760 [Accessed on: April 21, 2026].
11. Bernhard, R.P., Hörz, F., See, T.H. and Warren, J.L. (2001). Soft capture of earth-orbiting hypervelocity particles with aerogel. International Journal of Impact Engineering, 26(1-10). 39–51. DOI: doi.org/10.1016/s0734-743x(01)00076-8. https://ntrs.nasa.gov/api/citations/19980137657/downloads/19980137657.pdf
12. Aspen Aerogels. (2026). About Aspen Aerogels: A Technology Leader in Sustainability. [Online] Available at: https://www.aerogel.com/company/. [Accessed on: April 21, 2026].
13. Cabot. (2026). Aerogel Particles. [Online]. Available at: https://www.cabotcorp.com/solutions/products-plus/aerogel/particles [Accessed on: April 22, 2026].
14. Aerogeltechnologies.com. (2024). Aerogel Technologies, LLC | Engineer Limitless Possibilities(TM). [Online] Available at: https://www.aerogeltechnologies.com/. [Accessed on: April 22, 2026].
15. Woignier, T., Primera, J., Alaoui, A., Etienne, P., Despestis, F. and Calas-Etienne, S. (2015). Mechanical Properties and Brittle Behavior of Silica Aerogels. Gels. 1(2). 256–275. DOI: doi.org/10.3390/gels1020256. https://www.mdpi.com/2310-2861/1/2/256
16. Lerner, Eric J. (2004). "Less is more with aerogels." Industrial Physicist 10(5). 26-27. Available at: https://www.researchgate.net/profile/Eric-Lerner/publication/244425974_Less_is_more_with_aerogels/links/0a85e538a42f78361a000000/Less-is-more-with-aerogels.pdf [Accessed on: April 22, 2026]
17. Lin, P., Qing, X., Liu, Q. and Yang, Y. (2025). Flexible Aerogels for Thermal Insulation: Fabrication and Application. ACS Applied Materials & Interface. 17(40). 55706–55719. DOI: doi.org/10.1021/acsami.5c12107. https://pubs.acs.org/doi/full/10.1021/acsami.5c12107
18. Fu, Z., Yu, D., Xue, T., Zhang, X. and Fan, W. (2025). 3D printed polyimide-based composite aerogels with shape memory and thermal insulation properties. Composites Communications. 56. 102335. DOI: doi.org/10.1016/j.coco.2025.102335. https://www.sciencedirect.com/science/article/abs/pii/S2452213925000889
19. Platt, K.H. (2025). NASA, SpaceX And Scientists Speed Up Human Race To Colonize Mars. Forbes. [online]. Available at: https://www.forbes.com/sites/kevinholdenplatt/2025/05/24/nasa-spacex-and-scientists-speed-up-human-race-to-colonize-mars/ [Accessed on: April 23, 2026].

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