Red Rover

by Roger Wiens

  On the monitors I could see several people dressed from head to toe in white cleanroom garments. They were already wearing laser eye protection: large white goggles with dark panes. Overall the workers bore a resemblance to Star Wars storm troopers. In the background I saw an immense conical object that had to be the entry capsule, inverted on a fixture. In another direction lay an ungainly contraption sprouting fuel tanks, hoses, rocket nozzles, and support struts. This was the retro-rocket package, affectionately known as the EDL stage (for entry, descent, and landing), and Sky Crane, which would hover over the surface of Mars as it winched the rover to the ground. In the foreground was a large white box sitting on metal legs and bristling with cables and connectors. It looked nothing like a rover, but it was in fact Curiosity mounted on a large stand, its aluminum and titanium wheels removed. It had just been turned right-side-up after being inverted earlier in the week for installations on its underside. The 6-foot-long arm was disconnected, mounted to a fixture in another corner of the room. The mast that held ChemCam’s laser was lying flat against the rover deck and would have to be raised before we started our laser procedure.

  As we watched, the white-clad workers pulled a measuring tape up against the mast gimbal to measure the distance to where our engineers would set our targets. After the targets were in place above eye level on a tall tripod, a large black laser barrier was raised behind it. The six crew members stood by for the raising of the mast. The operators got bogged down with some bugs in a new version of the power-on sequence. Steve Bender and his French counterpart, Allexis Paillet, took a break, unsuiting and coming over to see us. I passed around Oreo cookies as we chatted over the experiments.

  We had a 277-page procedure to get through in our sixteen-hour day, and it was starting out slowly. By noon we were able to watch the rover raise its mast and point in the proper direction. By mid-afternoon we had focused the telescope and were ready to fire the laser. People stood around the monitors with cameras in hand waiting to capture the moment the rover fired its first shots. Sylvestre called from France, where it was nine hours later, already sometime after midnight Sunday morning. As I listened to his voice coming from around the globe I could imagine his quiet neighborhood in southern France, everyone sound asleep except Sylvestre. He wanted to see the first image.

  After commanding the rover to take pictures of the laser spot on our target, we got to a point where we had to check the instrument sensitivity with a special lamp. All the other lights were extinguished, and the spherical illuminator was turned on. For the next hour we sent commands to the rover sitting in the darkened room.

  The tests continued into the evening. The first-shift personnel had slowly filtered out and the rest of us became more quiet and subdued. It was a slow-motion race with the clock to see what we could accomplish before the 11:30 P.M. closing, and we were clearly going slower than we had been at midday. The humming fans in the electronics racks were trying to lull us to sleep. We fought the urge. Two and a half hours to go. The team got hung up on an alignment procedure. A calibration sensor couldn’t find the sweet spot of the laser beam, which we couldn’t see because of the goggles. Time passed. We gave it our best shot and collected the data for later analysis. Closing time had come and gone. The rest would have to wait for another day.

  And so it went as we made slow but sure progress checking out all aspects of the instrument. It was an on-again, off-again dance as the rover team juggled the ten instruments to be accommodated. For us it was frenetic activity and then inaction for several weeks, allowing us to plan for the next flurry.

  As winter came and then turned into spring, Curiosity reached a crucial stage—its own shake-and-bake tests were about to begin. Rarely does a spacecraft contain as many science instruments as this rover. If a part of the rover or any one of its experiment packages failed, time could get critical. Occasionally, we discussed what might happen if something needed to be unbolted for repairs. The offending instrument would have to go back to its home institution and one of two scenarios would ensue: the instrument would either be fixed so that it could be reunited with the rover at the launchpad, or, if the problem was bad enough, the rover would have to launch without it.

  Normally, when we put an instrument through a vibration test—the “shake” part of “shake and bake”—we turn it on briefly after each of three axis tests so we can see if it failed, and if so, why. Checking its full functionality at the end of the test is another important step. However, the rover leadership decided it would take too long to check out all the instruments during or even after vibration; Curiosity would head straight for the next activity without any verification. We were a little concerned.

  The thermal chamber is a large round structure about 25 feet in diameter in a building near the top of the hillside on which JPL is situated. Its outer walls are crammed with metal pipes used to carry liquid nitrogen at –195°C (–320°F) to simulate outer space, as well as heaters to simulate warm places in the solar system. The rover was placed in the center of the chamber with rock targets mounted in various locations for the laser to shoot at. When all was ready, the doors were closed, and the air was pumped away. Curiosity was in the position we hoped it would be in when it touched the surface of Mars, with its arm and mast stowed. The first activity was to fire the pyro charges that would deploy the mast. This had always been a worrisome activity for our team. The explosive bolts were potentially forceful enough to shatter the glass in ChemCam’s telescope. Early in the project, the engineers had estimated that the shock from the bolts would be especially severe on our instrument. They later downgraded the severity of the shock, but we were still concerned. This was our first real test. Once they were detonated, ChemCam was to take pictures and fire at its calibration targets.

  Finally ChemCam’s first data came back from the rover. We breathed a huge sigh of relief when clear, sharp images came back, followed by LIBS spectra showing the elements present in the target. Everything had gone well for ChemCam—both the vibration test and the shock from the bolts. As the thermal trials—the “bake” portion—progressed through most of March 2011, we learned that all was well with the other nine instruments as well. There was only one slight electrical short in a cable on the arm, something that could be easily fixed. Curiosity was a real success so far.

  After the test concluded, the rover was returned to its assembly area. Members of the press were allowed to suit up and go in to see the six-wheeled marvel. In a few weeks it would head to the Cape. There it would be mated up with its power source, the RTG. Each instrument, along with critical systems—arm, mobility, antenna—would get a very brief test with the radioactive unit installed. Then the unit would be removed and the rover would be folded back up and mated with the EDL stage that would lower it to the ground. The EDL stage would be fueled, and one final inspection would precede the package’s installation into the capsule. The RTG would then be reinstalled through an opening in the capsule. Finally, the whole thing would be mounted onto the second stage of the rocket in the payload faring—the nose cone of the rocket. The journey was about to begin.

  PART III

  CURIOSITY

  chapter

  nineteen

  COMING TOGETHER

  IN CONTRAST TO THE TWIN ROVERS OF 2003, WHICH HAD BEEN directed largely by one person, Curiosity is led by a team consisting of the leaders of each instrument. In the previous mission, Steve Squyres had picked the instruments he wanted and had written his proposal. In our case, each instrument leader had written his or her own proposal. On the day the selections were announced in late 2004, we found out who we would be sharing the rover with—our “shipmates.”

  My first introduction to the leadership circle was at Curiosity’s kickoff meeting in early 2005. I arrived at the meeting late, having purposely booked a tight itinerary to maximize my time with my family. When I entered the Pasadena hotel ballroom where everyone was gathered, I could feel an air of excitement. The room was crowded with eng
ineers from JPL as well as Mars scientists from all over. Slipping past the people bunched in the doorway, I found a seat in the back row, as usual, and opened my laptop. Just as I was starting to take notes I noticed someone trying to get my attention. The person jostled his way to where I was and told me that I had to sit at the front of the room, where a name card was holding my place at a long table. I was clearly not used to this status. At the next opportunity I slid up the side of the room and found my place at the front. New colleagues on my right and left greeted me.

  At the table were the other eight leaders of the various instruments on Curiosity. This was the new Mars Club, and I was now a part of it. I knew almost all of the individuals a little, but we had never worked together. It looked like I was the youngest person in the club.

  At the far end was Mike Malin, an imaging expert and the oldest in the group. After working with cameras at JPL early in his career, he eventually moved to San Diego and started his own successful company building cameras for spacecraft. If anyone knew Mars, it was Mike. His cameras had taken literally millions of pictures from spacecraft launched to the Red Planet between 1996 and 2005, and Mike must have seen every single photo. He seemed to know every square foot of Mars like his own backyard. Mike confidently spewed advice on any project he took on.

  Next to him was Ken Edgett, his companion at Malin Space Science Systems. The two had worked together for a decade and they shared responsibility for three science cameras on Curiosity: a set of stereo imagers called Mastcam, an arm-mounted microscopic camera called Mars Hand Lens Instrument (MaHLI), and a Mars Descent Imager (MarDI) to snap pictures as the rover approached the ground. Ken knew Mars almost as well as Mike did, though his style was slightly more diplomatic than Mike’s. Both were very business smart. When they learned that ChemCam was to get sharper images than Mastcam, they changed their design just to beat us. We didn’t mind. The two San Diegans both wore wire-rim glasses. Mike’s were small and round; Ken’s were a larger and older style. Both had science-fashionable beards. Ken almost seemed like a slightly taller version of Mike.

  Next to them was Paul Mahaffy, from Goddard Space Flight Systems in Maryland. Paul was new to Mars, but he was a longtime veteran of space. He had joined Goddard after finishing his education in Iowa. Once at Goddard, he was under the wing of Hasso Niemann, a space patriarch of sorts who had built sensors for the atmospheres of Venus, Jupiter, and Titan, Saturn’s moon—almost every atmosphere in the solar system. Paul looked the part of a scientist, sporting a graying beard, blue eyes, ruffled hair, and a slightly wrinkled shirt. His demeanor was much kinder than one would expect from such an authority. Perhaps it was because he had grown up in Ethiopia watching his parents care for underprivileged people. Paul was leading the biggest instrument on Curiosity, a set of sensors for the detection of gases and organic materials in Mars’ rocks and in the atmosphere. Simply named “Sample Analysis on Mars” (SAM), his was the instrument that would really search for life on Earth’s cold neighbor planet. SAM would turn out to be an amazing instrument. Weighing only 40 kilograms (90 pounds.), it would contain fifty-two micro-valves, a myriad of tiny gas lines, a turbo-molecular pump spinning at 100,000 revolutions per minute, an oven that could heat samples to 1100°C (> 2000°F), 74 cups for sample analysis, a gas chromatograph, a quadrupole mass spectrometer, and a laser mass spectrometer capable of detecting less than one part per billion of methane, an important tracer for life as we know it.

  Dave Blake completed the group of bearded faces at the table. Except for the whiskers and even bluer eyes than Paul, he looked like someone you might find on the beach in California. Always low-key, Dave lived in the Bay Area, where he worked at NASA’s Ames Research Center. He came with no prior experience on spacecraft instruments, but with the longest history of trying to break into the space business. His creation, CheMin, was every mineralogist’s dream—an x-ray diffraction (XRD) instrument. Scientists had been measuring elemental or chemical compositions on every mission to other planets, but they had not yet fielded a device to study mineralogy. So while previous landers and rovers could detect silicon, they could not tell, for example, whether it was in the form of quartz, which comes from a long evolution of magma types, or of opal, which is produced by the interaction of water on the surface. CheMin could make that distinction easily. But the prior dearth of such instruments was not from lack of trying. Portable XRD instruments had been envisioned and even partially developed ever since the Apollo missions, but they never managed to get on board. The MERs, Spirit and Opportunity, were supposed to have a different type of mineralogy instrument, a Raman spectrometer, but it got canceled. Now Dave carried the flag for the mineralogy community.

  Dave’s instrument was to be built at JPL, not at his home institution. That suited Dave just fine. He remarked later that at first he tried to take as many trips as possible to JPL to make sure everything was going okay on CheMin, but after a while he realized that they really didn’t want him interfering. JPL came up with an amazing instrument, and he was free to pursue other things—such as being chased by polar bears above the Arctic Circle. While the instrument teams were sweating the myriad of details, Dave and a few other colleagues wrote a proposal to do fieldwork in Svalbard, a group of islands farther pole-ward than Iceland and the boreal coast of Lapland. NASA awarded them the work and off they went on several consecutive summers, packing portable instruments with them. Upon their return, Dave and his friends regaled us all with stories of fending off the hungry man-eating polar bears that arrived at the islands on ice floes.

  During a bout that Dave Blake had with ill health, another colleague was called in to colead CheMin. Dave Vaniman, from my institution, had been working with Blake on the XRD concept for over a decade. Vaniman was also a native Southern Californian. His family had a long history in the area, as evidenced by the photo in his dining room showing what is now the area of Hollywood and Vine Streets covered with fields. The people in the picture were threshing wheat using horses. Dave himself grew up on a sharecropper farm in Simi Valley. His upbringing had some things in common with mine. He had gone to Africa with the Mennonite Central Committee, a relief organization, to dig wells and teach. Being from a Mennonite community myself, I had always expected to go into work like this, but it never happened. After coming back from Africa, Dave ended up digging wells much of his career, not to supply water, as earlier, but to study the geology underneath Los Alamos National Laboratory in order to understand the flow and spread of contaminants in the groundwater. As a result, he knew the types of rocks that underlay every part of our county and a good deal besides.

  Also at our table were a couple of people representing instruments contributed by foreign governments. Igor Mitrofanov, from Moscow, was sitting right next to me. He was to supply a Russian neutron spectrometer based on a deal between the heads of the two countries’ space agencies. Dr. Mitrofanov seemed to be an expert at international politics, as his Curiosity instrument was not at all the first such arrangement. Originally, neutron spectrometers had been used in the nuclear weapons industry, and so installations in the Soviet Union as well as weapons labs in the United States excelled in this technology.

  At Los Alamos, the members of our spacecraft instruments research group were proud of the fact that they had flown the first neutron spectrometer to be used for planetary science—one that had discovered ice at the poles of the Moon. However, subsequently they were scooped on first one mission and then another by NASA’s international deal-making with Igor Mitrofanov. In the first instance, NASA had to bail out the Russians because they didn’t have enough rubles to finish the project. So my colleagues were furious when NASA accepted a Russian “gift” for Curiosity, expecting that in the end NASA would again have to bail them out. My Los Alamos friends who had focused on developing neutron spectrometers for space saw careers going nowhere, and they eventually left Los Alamos to go on to other things. As it turned out, the Russians didn’t need bailing out this time.

&nb
sp; A representative of the Spanish space agency was also at the table, leading a team that was building a Mars weather station. This instrument represented an awakening interest in space science by Spain, a country that would host major science conferences and sponsor new instruments in the coming years. Javier Gomez-Elvira eventually took charge of this instrument.

  Ralf Gellert, previously from the Max Planck Institute for Chemistry in Mainz, Germany, was the leader of the APXS composition instrument to be mounted on the rover arm. APXS had been a German contribution for Pathfinder as well as the MERs. However, in an interesting twist, the German government had refused to support another APXS experiment. The Canadian government had wanted to get in on the action, however, so Ralf pulled up stakes in Europe and became a Canadian, surrounding himself with a Canadian team to make it happen.

  Rounding out the instrument leaders was Don Hassler, a suave-looking scientist from Boulder, Colorado, who clearly defied the geek stereotype. His responsibility was a radiation monitor that NASA’s human exploration department was sponsoring to help determine the dangers for astronauts on future trips to Mars.