IE 11 is not supported. For an optimal experience visit our site on another browser.

Chemist cooks up ‘solid smoke’

Researcher Steven Jones is a master chef for aerogel, an ultra-lightweight, ultra-strange material used in NASA interplanetary missions.
Steven Jones, a researcher at NASA's Jet Propulsion Laboratory, holds a flask containing a clear liquid that will be turned into aerogel.
Steven Jones, a researcher at NASA's Jet Propulsion Laboratory, holds a flask containing a clear liquid that will be turned into aerogel.Jim Seida /

The cabinets in Steven Jones' laboratory are full of the stuff: black-tinted slabs, whitish domes and cylinders, translucent blocks the size of ice cubes and irregular rocks that almost disappear when you take them down and hold them in your hands.

The stuff, called aerogel, is an ultralight material that's nearly as weird as the flubber from "The Absent-Minded Professor." Guinness World Records recognizes it as the world's lightest solid, consisting of 99.8 percent air and 0.2 percent silica dioxide.

It's been used as a heat insulator on the current Mars rovers and the next probe to visit Jupiter's moons. And on NASA's Stardust spacecraft, it serves as a kind of cosmic flypaper for interplanetary particles.

All that aerogel was cooked up in Jones' lab, around the back of a building at NASA's Jet Propulsion Laboratory.

Jim Seida

The setting — complete with a chest-high pressure cooker, loops of plumbing, dangling sheets of plastic and huge glass flasks — would be perfect for a mad-scientist movie. The fact that the chemist maintains a clean-room environment to eliminate outside contamination only adds to the mystique.

But as he stands amid all that equipment, wearing coveralls, booties and a plastic hairnet, Jones doesn't look at all mad. In fact, he looks like one happy scientist.

"That's the good part of my job," he says. "I get to play around."

For Jones and many other researchers, the opportunity to play around on a scientific frontier provides an important motivation for innovation. And aerogel is the kind of substance that invites playing around.

Jones developed his appetite for scientific play during childhood. He recalls the time he and his brother took apart his mother's broken hair dryer, then put it back together — without the electrical transformer. "When we plugged it in, you should have seen the sparks flying!" he says.

He calls himself a "failed physics major" who went back to school to get his chemistry degree. After getting his Ph.D., he came to specialize in sol-gel chemistry — the science behind aerogels and similar substances. In 1996 he answered an ad looking for "someone knowledgeable in aerogels for Stardust," and he's been at JPL ever since.

Geniuses with gels
Aerogel was invented in the 1930s, and even before Jones arrived on the scene, JPL researcher Peter Tsou was cooking up batches for space shuttle experiments and the 1997 Mars Pathfinder probe.

But today, Jones ranks alongside Tsou as a master aerogel chef. Jones' genius lies in fiddling with the basic recipe of solvents and metal compounds, then drying the concoction just so in the pressure cooker.

Jones recalls a conversation he once had with Tsou about writing down the recipes. Tsou was concerned that they'd be giving away their hard-won secrets, but Jones says he reassured his colleague: "Oh, Peter, don't worry about it. Even if we write out exactly what we do, there are so many little nuances we don't write out that they won't be able to repeat what we do."

If the batch turns out wrong, the aerogel looks like a slice of tofu that's gone bad. But if it turns out right, it looks like "solid smoke," with a faint bluish tinge.

Aerogel can be such a good thermal insulator that you could point a blowtorch on one side and hardly feel the heat on the other side. That's why the Mars rovers are equipped with sheets of aerogel, tinted black to cut down on infrared heat transmission.

Aerogel is so absorbent that it can snag bits of cosmic or cometary dust as they zip through space faster than a bullet. That's why blocks of the stuff were put into Stardust's sample collection trays for analysis when the spacecraft returns in 2006.

NASA says a block of aerogel the size of a human being can weigh less than a pound (455 grams), and yet support an object weighing half a ton.

So if this stuff is so good, why don't we see aerogel at the hardware store? Jones explains that the ultra-lightweight material is just too expensive for everyday use.

"People ask me, 'When is my grandson's house going to be insulated with aerogel?' And I say never," Jones says. "If we decide to build a city in Antarctica, or a moon base, then the efficiency of it overtakes the cost. But contractors building a building couldn't care less what it weighs. They care about the cost."

The future of a space oddity
Not that companies aren't trying: Massachusetts-based Aspen Aerogels, a beneficiary of NASA spin-off technology, has made deals to put aerogel into military satellites, aircraft, energy-saving windows, ski-boot insoles and winter parkas.

Scraps of Jones' aerogel already have been transformed into artwork, and even less conventional applications are on the horizon. For example, aerogel could someday provide the raw material for mass-produced carbon nanotube fibers.

In the meantime, Jones keeps working on his custom-made aerogels. His latest project is to produce thermal insulation material for the nuclear-powered Jupiter Icy Moons Orbiter. He's also been working with researchers at the University of Southern California on adapting aerogel for use in miniaturized vacuum pumps.

Along with some colleagues, Jones has submitted a report to JPL on potential advances in aerogel insulation. He says the laboratory and its parent university, the California Institute of Technology, may well take the commercial route "if something comes out of what we're doing that's innovative and patentable."

But for JPL and Caltech, the patents aren't as important as providing NASA with what it needs for future missions. And as long as NASA needs aerogel, Jones will keep cooking.

It's a vocation worthy of Professor Brainard, the inventor of flubber in "The Absent-Minded Professor." So does Jones see any parallels between flubber fiction and aerogel fact?

"In the oddity of the material, yeah," he says with a laugh. "It's a mixture between art and science. I think there's a grain of truth there."