Robot Twins Readied for Journey to Mars

Swathed head to toe in surgical garb and huddled over a table, George Nakatsukasa slowly places a sturdy cover over the electronic heart of his six-wheeled patient. Across a room so clean it contains almost no dust, dozens of engineers are circling a second robot, peering beneath layers of aluminized plastic at the thick ropes of cable emerging from its torso.

The quiet focus in this room at NASA’s Jet Propulsion Laboratory contrasts starkly with the commotion and media glare encircling Johnson Space Center in Houston -- where the loss of the space shuttle Columbia has brought manned spaceflight to a grinding halt.

The challenge of space exploration now has fallen heavily to the engineers at JPL, who have been working for more than a year at a breakneck pace to send twin handcrafted robots to Mars.

The assembly and testing of these sophisticated vehicles has been under intense time pressure from the start. The breakup of Columbia came as engineers in Pasadena were in a last, difficult stretch: the push to finish the rovers and send them to Florida for launch this summer. The team has had little time to pause, let alone grieve.

When he heard the news about Columbia nine days ago, Nakatsukasa stopped in his tracks. Then he headed into work. He had to. New hardware was waiting to be installed.

“We can’t slow down,” said Nakatsukasa, a lead technician with the team building the rovers. “We’ve got a launch window to meet.”

The Mars craft will be ferried into space separately in May and June, not by a shuttle but by Boeing Delta II rockets.

JPL’s mission of robotic space exploration is detached enough from the astronaut program that the accident provided no reason for delay. In fact, the crash only strengthened the resolve of many at JPL.

“Explorers don’t back off,” said JPL Director Charles Elachi, who called an “all-hands meeting” of employees the Monday after Columbia disintegrated over Texas, killing the seven astronauts aboard.

“I told them the best thing you can do to honor the astronauts is go back to your offices and work on this.”

Delaying the $800-million mission to determine whether Mars could have once sustained life is not an option, because the launch window opens only once every 26 months.

By examining chemical and mineralogical clues hidden within Martian rocks, the “robot geologists” will seek proof that the water necessary for life once was present in large amounts on the now-cold planet’s surface.

There are more ambitious plans -- to drill into the Martian surface, embed equipment to provide a continuous stream of data and images and bring rocks back to Earth for analysis.

But they depend on what is learned during this trip and future missions scheduled for every launch opportunity over the next 15 years.

The pressure for this mission to succeed -- already high because of the loss of two Mars spacecraft in 1999 -- has increased since the Columbia tragedy.

“It added pressure, and we were already as committed and as pressured as possible,” said Randy Lindemann, the lead engineer responsible for designing the rover.

“Like a team that lost a few outings and now faces a bigger game, we’ve got to win.”

A small rover was supposed to fly in 2001, but that trip was canceled after an independent review of the 1999 failures criticized NASA for trying to do too much on what amounted to a shoestring budget. Instead, officials decided to wait and attempt a more challenging mission, using the two rovers.

As the mission evolved, the rovers themselves became much bigger. At 368 pounds, they eclipse the Sojourner, which at a diminutive 25 pounds landed on Mars in 1997 after its launch in 1996 aboard the Mars Pathfinder. The new Mars exploration rovers can travel up to 100 yards a day -- the distance Sojourner did in its entire three-month mission.

“Basically, this is a robotic geologist in an SUV,” said Mark Adler, the lead landing engineer.

The twin explorers are packed with high-tech instruments and hardware that make them seem eerily human. The camera, with binocular 20/20 vision coming from two separate “eyes,” stands about 5 feet off the floor.

A 3-foot-long arm with a shoulder, elbow and wrist for flexibility will be able to scratch the surfaces of weathered rocks and then analyze the rock interiors with a microscope just as a geologist would.

Three spectrometers -- or chemical analyzers -- will study elements, minerals and compositions of rocks to look for evidence of past water and try to determine what conditions on Mars may have been like when the rocks formed.

The rover cameras will send back images so clear and colorful, “they would look good projected on an IMAX screen,” said Steve Squyres, a Cornell University geologist in charge of the rovers’ science instruments. “These are going to show you Mars like you’ve never seen Mars before.”

Building two robots simultaneously, installing the instruments and making them work in concert has been a huge challenge, said Matthew Wallace, the engineer overseeing the assembly of the robots at the JPL. “We have three or four missions packed into one,” he said.

Because the rovers are bigger and more rugged than Sojourner, they need larger solar arrays for power and more antennae to send back data. As the robots packed on more pounds, it became clear that the vehicle that transported Sojourner into the heavens wouldn’t suffice. In recent months, engineers have had to create an entirely new lander as well.

“It turned into a much bigger job than we realized,” said Lindemann, who described the months of reengineering as “brutal” and “thrilling.” “Every aspect took the lab to its maximum capability.”

The biggest technical challenge for those assembling the transport spacecraft was finding a way to fit the rover -- which is bigger than a Saint Bernard when unfolded -- into a far smaller and oddly shaped flight capsule. It was a geometry problem of the highest order.

“Making a rover that starts as a tetrahedron and ends up as a rectangle is an extremely difficult challenge,” said Chris Voorhees, the “wheel guy,” or engineer in charge of the mobility systems on the rovers.

Once on Mars, the rovers will perform what Adler calls “a reverse origami trick.” The landing vehicles will open their “petals,” exposing the tightly packed rovers. Then the robots will emerge and, with the help of some pyrotechnics, stretch out their wheeled legs, send up their masts and cameras and take their first look at Mars.

“In some ways, it’s an audacious thing to try. So many things have to work in sequence,” Voorhees said.

For those in the clean room, the disintegration of Columbia was a painful reminder of the hazards of spaceflight. Going to Mars is, as NASA Associate Administrator Ed Weiler says, “not a trip to Grandma’s house.” While one of every 60 shuttle flights has ended in disaster, two of every three trips to Mars have failed as well.

Engineers are most nervous about landing on Mars, where the 400-pound capsules will smack hard onto the cratered planet, protected only by inflatable air bags. The biggest hazards are sharp rocks and Martian winds that could carry the lander into a crater wall.

Those assembling the rovers are doing everything they can to reduce other risks. As has now become routine at the JPL, “checkers are checking the checkers,” engineers say. In the clean room, workers do whatever they can to make sure no errant eyelashes, pieces of dandruff or even fingerprints hitch a ride aboard the two rovers. Even the smallest bit of skin or oil could damage fragile electronics or fog camera lenses.

Everyone working here knows there is a chance, a big one, that the twins won’t survive their seven-month, 286-million-mile trip. Launch, cruise and landing all carry their own suite of hazards. Columbia’s loss makes that achingly clear.

Phil Christensen, a planetary geologist at Arizona State University who studies Mars, didn’t need the reminder. He lost decades worth of work when an instrument that his lab designed and built to analyze Martian minerals disappeared in 1993 with the Mars Observer spacecraft, which launched in 1992.

Instruments he has placed aboard two subsequent orbiters, however, have been a resounding success. The information he has gained is shaping exploration plans for the current rovers, which will each carry a new thermal, infrared instrument of Christensen’s.

“I am just as proud, if not more so, of our efforts on the failed Mars Observer mission as our successes on Mars Global Surveyor and Odyssey -- the attempt was what was important,” Christensen said. “The fact that people have the audacity and courage to attempt to send robots to Mars or humans into space is remarkable, and this audacity is what I think will be remembered 200 years from now.”