The Stars of Mars
AS THE MARTIAN rover paid courtesy calls up and down Ares Vallis last week, she showed the exemplary manners expected of any ambassador. Before reaching out with her Alpha Proton X-Ray Spectrometer for a 10-hour handshake with ""Barnacle Bill,'' the rover first rolled toward this blue-gray stone at a stately half inch per second. Tipping a bit as she went over a small rock, she recovered gracefully, backed up about 12 inches and stuck her spectrometer onto Bill. She collected data on what he was made of. Then, commanded by controllers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., 119 million miles away, she set off on her next visit: to Yogi. Despite a slight fender bender en route that left her hung up on Yogi's face for two days, she was expected to relay more data to JPL. Those results, and the stark photos of the rock-strewn Ares Vallis region, made the Pathfinder mission seem like the best thing to ever hit NASA's Mars program. Except that some NASA officials believe that honor belongs to a very unlikely candidate. In August 1993, just three days short of its orbital rendezvous with the Red Planet, the Mars Observer spacecraft mysteriously disappeared. It had been, as NASA Administrator Daniel Goldin puts it, ""the last ship out of port.'' Stuffed with scientific instruments, the $980 million mission exemplified the old NASA: loading up a spacecraft with every instrument scientists could think of, but then not sending another probe for a decade or more. A few months after the loss, Goldin visited a lab at Arizona State University. The scientists and graduate students there had just seen eight years of hard work on Mars Observer vanish. As the students stood around looking glum, Goldin announced the dawn of a new era, his listeners recalled. The loss of Observer, he declared, was the best thing ever to happen to America's Mars program. Now NASA had an open field to explore the solar system in a new way.
That new way is encapsulated by three words that Goldin has made the agency's mantra under his five-year reign: better, faster, cheaper. Pathfinder's success, from its never-before-attempted landing on 17-foot airbags through the first-ever mobile exploration of another world, shows that the right stuff can be bought for a supersaver fare. It can also pump up public, media and presidential interest in the space program. Pathfinder Web sites recorded 220 million hits the first five days. CNN seemed to be gunning for the position of official Martian network. Bill Clinton, channel-surfing in Warsaw, ""could not turn it off. It's just thrilling.'' And suddenly, there was serious talk about sending astronauts to Mars early in the 21st century.
At first many NASA vets were skeptical of the cut-rate approach. ""When we got close to launch and were still under the [budget] cap,'' said Pathfinder manager Tony Spear, ""other [NASA] managers told me they hadn't thought we'd make it.'' But they did, even returning hundreds of thousands of dollars to the NASA kitty. It helped the bottom line to let well-paid, long-serving space jocks retire and make way for kids happy to work long hours, to put their personal lives on hold, and even to plan things so their first baby isn't born for a good two months after Pathfinder landed. ""The idea was to grab young scientists who didn't know the job was "impossible','' says flight-software engineer Steve Stolper of JPL. Can this ""better, faster, cheaper'' be replicated on future missions?
Like Pathfinder, tomorrow's missions will be designed in NASA's new risk-taking culture. ""We can tolerate failures,'' says Goldin. ""We want to encourage people to take risks in spacecraft design.'' Risk means that NASA's days of quintuple redundancy are gone. There is only one radio receiver on the Pathfinder lander, for instance. If it fails, the rover cannot execute commands radioed up from JPL to the lander and then relayed. A tolerance for risk also means forgoing some certainty. Every previous lunar or planetary lander had been carried up to 120,000 feet at Mach 2 and then dropped to see how the parachutes worked. Viking, which touched down on Mars in 1976, underwent such tests, at $10 million a pop. Partly because Pathfinder was using the same parachute design as Viking, and partly to save money, ""we didn't do these tests,'' says JPL's Brian Muirhead.
But accepting risk didn't mean that the rover team would take a chance that Sojourner would get stuck in some Martian cul-de-sac, or flip over and become as immobile as a supine turtle. Every Sunday night David (The Gremlin) Gruel locked himself inside Pathfinder's test bed - a sandbox - and pulled the blinds. There, alone, he took out his shovel and bag of rocks and did his worst. He built sand piles, rocky hills and boulder clusters, practically taunting the rover engineers to navigate them safely the next week. ""The one that stumped the guys the most,'' says Gruel, 27, ""actually happened.'' That was when he inflated the airbags under the lander's ""petals'' so they blocked the rover's exit down the ramp. The Sojourner team solved the puzzle by repeatedly lifting and lowering the petals and deflating the bag - exactly as they had to do the day after landing.
Another cost-saving move is to buy more parts off the shelf (diagram). The telecommunications team for the Sojourner rover realized that they couldn't design and make modems any better than the Motorola RNET 9600 and still meet the cost cap and launch date. In 1995 they bought 30. The engineers subjected them to frigid Martian temperatures, replaced plastic connectors with wires and substituted fiberglass and aluminum tape for the original metallic outer box. The $695 Spacetech IMC ""spaceball'' used to control the rover from JPL like a character in a videogame didn't even have to be modified.
Upcoming missions to Mars - one orbiter and one lander every 26 months - follow the Pathfinder script. Take the Global Surveyor, which begins mapping Mars next March 15. Its infrared camera captures unique radiation signatures emitted by different minerals, says Arizona State's Philip Christensen. Among the targets: carbonates, cherts and opals - all characteristic of thermal hot springs. Thermal springs may be the likeliest places to find signs of life on Mars. But not even a goal as grand as finding where life lived on Mars meant Christensen could spend like a teenager with his father's credit card. He had to design, build and deliver the camera for $8 million, compared with $22 million for an identical one on the lost Mars Observer. Why the big differential? First, says Christensen, ""this is just a copy. So that argues for flying the same [kind of] instruments on several missions.'' Second, the price of the first spectrometer shot up when NASA, at the last minute, ordered the Arizona team working on Observer to use better quality parts. ""We were told, "This is a very expensive mission. It has to work','' recalls Christensen. ""So I bought thousands of spare parts and tested them all. That raised [the camera's] odds of success from 95 percent to 98 percent - at a cost of several million dollars.''
David Paige has also felt NASA's belt-tightening. The UCLA geologist and colleagues are providing the scientific payload for the next Martian lander, due to touch down on the Red Planet's equivalent of Antarctica in December 1999. The Mars Volatiles and Climate Surveyor would be the first Martian prospector cum chef. A six-foot robot arm will dig as deep as 18 inches, scoop up soil and feed it into an oven. The guiding principle here is that you can tell what's in something by smelling what wafts out when you cook it. (Paige's instrument will determine the chemical composition of emissions from the heated sample.) ""We had $20 million to build and deliver it,'' says Paige. ""We managed to do it with off-the-shelf technology and our own inventions.'' They had to invent the oven, but are adapting the rover's electronic controls and motors for the robot arm. And in a tectonic cultural shift, the 1999 mission will be run from several sites - JPL, but also UCLA. That way NASA doesn't have to spring for so many airfares and hotel rooms.
How low can a space budget go? Theoretical physicist Carl Kukkonen, who heads up JPL's ""microdevices'' lab, is readying $10 million probes that can be launched from the space shuttle on a rocket the size of a five-gallon gasoline can, or from the ground with a 10-foot-tall rocket ""that three of us could carry,'' says Kukkonen. ""We could be launching in the next decade.'' Each craft, hardly bigger than a birthday cake, would have its own navigation system. Each would be able to set its course by the stars and automatically correct it with tiny thrusters - all with no input from ground controllers. ""They're fire-and-forget spacecraft,'' says Kukkonen. Equipped with a camera to shoot photos of a planet or asteroid and a spectrometer to determine chemical composition, they could be launched at a rate of one a month.
OF COURSE, IF PATHFINDER had failed, then ""better, faster, cheaper'' would have looked like the dumbest idea since allowing the O-rings on the Challenger to become brittle. But it succeeded. Now NASA is applying that philosophy even to missions carrying astronauts. When President Bush asked NASA to cost out a crewed Mars mission, the agency came back with the idea-killing figure of $300 billion. Goldin has directed that the Johnson Space Center do it for $20 billion, tops.
A key to hitting this price point is to forget about carrying along fuel for a return flight. Extra weight means a bigger, costlier spacecraft and launcher. Instead, a lander arriving before the astronauts would make rocket fuel out of the carbon dioxide in Mars's atmosphere. It would also make oxygen, to supply the astronauts with breathable gas. The first oxygen factory will fly in 2001. Oxygen and fuel produced by a factory on the 2003 mission might be used to power a small rocket that would lift off from the surface of Mars, shoot some pictures, then land. If that works, the 2005 mission may use made-on-Mars fuel to power a spacecraft that would bring rock and soil samples back to Earth.
Perhaps as early as 2011, if all of this works, Earthlings might staff a permanent Martian station. ""Eventual Mars settlement,'' said Elric McHenry of NASA's Advanced Projects Office, ""is a guiding principle of our current planning.'' But the rent will have to be cheap, too. Goldin has so embraced the ""living off the land'' philosophy that he says astronauts will grow their own food on Mars, too. Other schemes: zapping the Martian permafrost with microwaves to extract water, mixing the water with Mars's claylike red dust to make bricks, turning the calcium and sulfur in the soil into gypsum.
If Sojourner's limited exploration is any indication, such a self-reliant settlement could be nestled in a landscape of quiet majesty. Scientists knew that Ares Vallis had been swept by a flood of Biblical proportions more than 1 billion years ago, so the ""discovery'' of such a flood, as trumpeted by headlines last week, wasn't really one. But the rover did turn up some surprises. Her analysis of Barnacle Bill found a rock as rich in silicon dioxide - quartz - as any in Earth's continental crust, said geologist Harry McSween of the University of Tennessee. Quartz can form from a complex melting and remelting of rock - ""or of melting in the presence of a lot of water,'' says McSween. It's too early to know whether the arid, barren surface of Mars hides a watery interior -and hence more chances to create Martian life as well as to support, one day, Earthlings. But the real payoff of Sojourner and Pathfinder has been to drive home something that no space mission ever has. ""It's being shoved in our face that there is a whole world up there, with mountains and hills and craters,'' says engineer Robert Zubrin, who helped conceive live-off-the-land. ""What Pathfinder is doing is making Mars sensuous.'' And changing the face of space exploration. Within 15 years, astronauts on Mars may stumble upon the still and silent Pathfinder and Sojourner, their batteries long dead and their mission long over, and recognize them as the pioneers that put Earthlings on course for the Red Planet.
Pathfiner landed in Ares Vallis, where a huge flood washed down rocks from the highlands 1 billion to 3 billion years ago. The rover examined two of the rocks last week for clues to Mar's past.
1. Flood plain: The tilt of the rocks shows that the flood, hundreds of miles across, washed down the valley from the southwest.
2. Lander: Renamed Sagan Station, Pathfinder opened its 'petals' after landing and extended its ramps. The rover tolled out and went to work.
3. On a roll: The spectrometer on the rover determined the elemental composition of rocks and soil by bombarding them with alpha particles.
4. Close encounter: On July 6, the rover planted its spectrometer on Bill. It contains abundant quartz, formed by melting and remelting.
5. Moving violation: After dislodging a wheel that became stuck July 9, the rover prepared to chemically analyze Yogi.
Sojourner was fitted with many items that were purchased off the shelf and extensively adapted for the use on Mars. Here are some of them:
Power converters: Three Pico Electronics converters, costing about $35 each, became part of the $2.5 million electronics boards.
Modems: Two $2,000 Motorola radio modems (one is in the lander). Cost to adapt: about &750,000.
Cameras: Three $400 Kodak cameras. (One camera is in the back). Cost to adapt: $300,000.
Motors: Eleven $100 Maxon motors purchased from Switzerland. Cost to adapt: $220,000.