Prometheus 6

When I first heard of this stuff I wasn't sure someone wasn't hustling folks. Now I find it not only really exists but that there's varying flavors of it...that it's not so much a matter of the material it's composed of but the physical arrangement of the material that makes it capable of the things that made me doubt its existence.

Back on Earth aerogels may have many other applications. The material is already being crushed up and used as insulation in extreme weather gear like snowsuits as well as spacesuits. Another possibility is developing aerogel-based capacitors--energy storage devices--for powering cell phones and cars; the large surface areas of carbon aerogels could store enormous amounts of electric charge compared with their traditional battery counterparts. In addition, researchers at Lawrence Livermore National Laboratory have made iron oxide aerogels embedded with nanoparticles of aluminum that react with the oxidizing gel, releasing an immense amount of heat that could be useful as rocket propellants, in explosives or for pyrotechnics. Similarly, carbon aerogels impregnated with nanosize particles of precious metals like platinum could serve as catalytic converters in cars that would require a fraction of the rare metal to perform the same function. For such a lightweight substance, aerogels have a lot of heavy-duty applications.

Strange but True: Gossamer Gel Stands Up to Flame, Speeding Space Particles
The next time you want protection from a blowtorch--or space dust--consider an aerogel
By Alison Snyder

Almost as light as air, capable of withstanding a direct flame or catching speeding comet dust like a baseball mitt stops a hardball, aerogels are some of the strangest solids in the world. This "Space Age Styrofoam" was developed in a chemistry lab decades ago but is now appearing in snowsuits, explosives and even energy storage technology.
Aerogels are the lightest and lowest-density class of materials in the world. Up to 99 percent of the dry, rigid gels are air, while the rest consists of silica, carbon, metals and other substances; it feels like a Styrofoam peanut. Yet, some formulations can support close to two thousand times their weight (if it is lowered onto them slowly). "Enough force to crush a Rice Krispie will crush an aerogel," states Stephen Steiner, a nanomaterials graduate student at the Massachusetts Institute of Technology and aerogel researcher.

But when NASA needed something to safely capture particles from Comet Wild 2 traveling at 6,000 meters per second as part of its recent Stardust Mission, the agency turned to the airy substance. A grid of silica aerogel within the spacecraft was able to catch the minuscule particles (smaller than a grain of sand) without damaging them in any way.

In addition, NASA's Mars Rovers were lined with the ultrainsulating material. Silica and carbon aerogels are poor thermal conductors, because there "isn't much matter there to do the job," according to Steiner. The porous, kitchen-sponge-like structure of aerogel forms a labyrinth through which it is nearly impossible for air molecules--and sound waves--to travel. Therefore, silica aerogel can protect a human hand from the direct heat of a blowtorch as well as dampen its roaring sound.