ScienceDaily (May 13, 2002) — A new version of aerogel, the particle-collecting substance on NASA's Stardust spacecraft, has been recognized by Guinness World Records as the solid with the lowest density.

Dr. Steven Jones of NASA's Jet Propulsion Laboratory, Pasadena, Calif., a materials scientist who created the aerogel used by Stardust, also created a lighter version that weighs only 3 milligrams per cubic centimeter (.00011 pounds per cubic inch.) The team received the official certificate yesterday.

Guinness World Records approved the new aerogel's application for the least dense solid in March. Astronomer David Hawksett, Guinness World Records' science and technology judge, decided that Jones' aerogel beat out the previous record holder, an aerogel that weighed 5 milligrams per cubic centimeter (.00018 pounds per cubic inch.)

Aerogel is pure silicon dioxide and sand, just as is glass, but aerogel is a thousand times less dense than glass because it is 99.8 percent air. It is prepared like gelatin by mixing a liquid silicon compound and a fast-evaporating liquid solvent, forming a gel that is then dried in an instrument similar to a pressure cooker. The mixture thickens, and then careful heating and depressurizing produce a glassy sponge of silicon.

What remains is sometimes called "solid smoke," for its cloudy translucent color and super-light weight. Surprisingly, this seemingly brittle substance is durable and easily survives launch and space environments.

"It's probably not possible to make aerogel any lighter than this because then it wouldn't gel," Jones said. "The molecules of silicon wouldn't connect. And it's not possible to make it lighter than the density of air, 1.2 milligrams per cubic centimeter (.00004 pounds per cubic inch), because aerogel is filled with air." To change the density, Jones simply changes the amount of silicon in the initial mixture.

Stardust will use aerogel to capture particles from comet Wild 2 in 2004. NASA used aerogel for thermal insulation on the Mars Pathfinder mission. It will also be used on the 2003 Mars Exploration Rover, and may aid a proposed fundamental-physics testing mission and the Mars Scout Program.

More information is available at: http://stardust.jpl.nasa.gov/tech/aerogel.html .

JPL is a division of the California Institute of Technology, Pasadena, Calif.

Email or share this story:  

Related Stories

Naval Research Laboratory Scientists Analyze Comet Wild 2 Samples (Dec. 24, 2006) — Scientists at the Naval Research Laboratory have analyzed samples from Comet Wild 2, as part of NASA's Stardust mission, the first solid sample return mission since Apollo. Over 100 scientists at ...  > read more

Guinness World Records Recognizes NASA Speed Record (Aug. 31, 2004) — Guinness World Records has recognized the world speed record set by NASA's hypersonic X-43A aircraft earlier this year in an experimental flight over the Pacific Ocean. Using a scramjet engine, ...  > read more

Faster Than A Speeding Bullet: Guinness Recognizes NASA Scramjet (June 23, 2005) — NASA has been officially recognized for setting the speed record for a jet-powered aircraft by Guinness World Records. NASA set the record in November during the third and final flight of the ...  > read more

Scientists Determine Strength Of 'Liquid Smoke' (July 31, 2008) — Researchers have created a 3-D image of a material referred to as "liquid smoke." Aerogel, also known as liquid smoke or "San Francisco fog," is an open-cell polymer with pores smaller than 50 ...  > read more

Search ScienceDaily

Medical Records on Your Cell Phone