by Rod Pyle
“So to keep it on budget, we thought the airbags would be the cheaper way to go. But it was also considered higher risk because we had never done it before. It had all these complexities that no one had ever dealt with; for example, how the hell to get out of it once we landed, how do you undress yourself on the surface of Mars without getting yourself wrapped up in knots and in tons of fabric? We had about two hundred pounds worth of fabric, and that's a lot.”
The worries and the testing went on, seemingly ad nauseum. But eventually the kinks were worked out, sometimes by trial and error. It was all so delightfully ad hoc and low-tech, but it worked, and soon they were ready to go. One huge advantage of such a low-budget mission was that NASA's expectations were minimal.
“The great thing about Mars Pathfinder was that [it was predicated on] a single page of level 1 requirements. These were: head to Mars in the 1996 launch opportunity, land in 1997, deliver a rover, send back some pictures, good luck, and here was some money to do some science if you have some time. So the mission was to show that NASA could do things cheaply, efficiently, and effectively, and of course demonstrate that there are efficiencies in a faster, cheaper approach. Of course, this hadn't really been defined yet, because nobody ever agreed on what that meant.”
This was the dictate of the then NASA administrator Daniel Goldin: faster, better, cheaper. It was not a bad idea in principle, but it had unfortunate consequences in many cases. However, Mars Pathfinder was one shining example of how it could work. One efficiency they achieved was to move the Pathfinder team, and the associated technical base, as close together as possible; it was almost reminiscent of the Mariner 4 days.
“We wanted to put all the team in one spot; we thought that was important. Now we couldn't quite achieve that, because of space availability issues at the lab at the time. But we got a majority of the core team members all in one spot. Communication was considered very important, teamwork was considered important, close management between the team was important, tight bandwidth between the team was very important; so we set it up to accommodate this. Also, don't overspecify things, it's okay to rely on oral communication as opposed to doing everything with legal documents, and above all keep it simple. That was our mantra.
“We didn't skimp on testing, though sometimes the test articles were low budget. But we didn't skimp on the tests themselves, so that was the overall model. The airbag was the perfect example of test-test-test. But there never seems to be enough people and resources to get the job done…. [T]here's never a sense of a forty-hour work week, it's almost a foreign concept. You can't predict scope with accuracy, yet you have to predict scope in advance to get the money, and there's a balance to what you can ask for and what you can get. You're expected to live within your means, so what happens is you get this variable called homelife, where you have to spend your time away from home all hours of night and on weekends.”
But if their domestic routines were scrambled, most of the participants in the Pathfinder project seemed to replace that (temporarily at least) with an almost religious fervor in the mission…and they enjoyed it: “At Pathfinder I think we had a lot of fun because there was more team spirit, more sense that the team members in all levels of the project, even if they were a cog in the bigger wheel, could participate in a whole function of the thing by watching it. Part of it was the smallness [of the team] and part of it was the fact that there wasn't a lot of institutional pressure. It was a fantastic experience, everyone [who] worked at Pathfinder [whom] I know think of it as nothing but a fun experience.”
Although the metaphor may be inaccurate, it is tempting to equate some of their fun with the toys at hand. Manning insisted, early on, that there be a way to test Pathfinder and the Sojourner rover in something remotely like a Mars-like environment close to the control room. This would help to avoid mistakes.
“Right above JPL's master control center was one giant room, and that room was for Mars Pathfinder. We had a sandbox in there, right above us. I had to do a lot of arm-twisting to convince people to bring in thousands of pounds of sandbox sand from down the highway in Monrovia. I wanted [the sandbox] right there so it could be the hub of our project.”
We know the story of Pathfinder…the revolutionary bouncing landing, the deployment and travels of the plucky rover. But for Rob Manning, it was not just the spacecraft, but the people—and their interactions—that were fascinating.
“Mars Pathfinder had a very interesting attribute. Because it was a small project, representing a small number of people, each doing a large number of things, there's a lot of diversity in what people did for a living; if you were an electronics guy, you might find yourself doing airbags one day, or doing retracting tests, or software. There were a lot of unusual relationships, and I did all sorts of goofy things, mixing people up based on their skills, attributes, and interests. In a major business this is unusual because normally you would have people who have an agreement to deliver certain products, and when they're done with the delivery they're off the job. I didn't believe in that, because it's not the most effective use of people. It was always a pleasure working with the capability of people, and to me one of the continuing returns of Pathfinder was to see all these people do things that they didn't think they could do.”
That said, it ultimately came down to the mission itself. It was a high-risk endeavor, trying lots of new techniques on the cheap. When it worked, the atmosphere at the lab was almost giddy: “I was the flight director during landing even, which really means that I knew when everything was supposed to happen, based on what the spacecraft was saying to us, which wasn't very much. We had a transmission delay of about eleven minutes at that time, so when we heard about it, it had either worked or it hadn't. During the landing, actually all the way down, I was giving a play-by-play on the net, with my headphones, and people were watching me as I was trying to interpret what I was hearing from [the tracking stations]…so it was really a lot of fun, and I was able to announce that it had landed, we had gotten a signal from Mars. It was really cool.”
Of course, this had been simulated over and over. When dealing with long delays and highly complex automated systems, simulation is the engineer's best friend. “We practiced through our simulation setup, which was right next to our operation area. We would put an eleven-minute light-time delay between what was going on [in]our test area and [in] our control room. So even though we could walk between one room and the other in about ten seconds, it was like adding two hundred million kilometers of distance. We had practiced it so much that when we actually landed it felt fake! It didn't really click, just how real this was, until we got our first photo back, and the we realized that this was Mars. So we got to the surface of Mars and went through the whole process of getting the vehicle deployed, and then the rover's standing up, all within twenty-four hours. This was on the fourth of July. The first pictures came back in the evening, at about five o'clock Pacific time; that was our first view of Mars, including the picture of the rover. It was pretty darned exciting. There were also a lot of interesting stories about what had gone wrong, and surprises we saw. We had interesting anomalies after we landed; for example, our inability to talk to the rover. Because the antennae were crossed over, we found out that the signals weren't getting back and forth [between rover and lander] like walkie-talkies as well as they should have.”
While the mission had flown under the radar for some time, when the landing was nigh, there was a ripple of delayed excitement—and concern—from NASA headquarters in Washington, DC: “We realized that Pathfinder was not going to be a little project. It might be little to us, but it was big to the outside world. We had so we lived [in the shadow of] of another mission, and much of NASA was just ignoring us. It wasn't until just before we landed that NASA upper management said, ‘We better check this project out…’ They knew about it of course, as they were funding us, but they were keeping their eyes away toward other challenges. They visited us just before we landed, and peo
ple like me told them why we thought this might work because they were not necessarily expecting success. They were hoping for success, but their confidence level was not very high.”
It was no coincidence that, while the pressure from NASA and JPL might have been lighter than other missions, the pressure from the outside world was immense—for Mars Pathfinder was the first mission that was truly live.
“The good news is that we had a talented webmaster. Recall that at that time, 1997, the web was still fairly new. So he figured out how to use mirroring, so that the public could go to different websites, depending on where you lived, and you'd be redirected to a different server that had the Pathfinder website mirrored. This webmaster went around and actually talked to all these other companies about hosting us for free, and he was successful at it. As a consequence, when people actually went to the web to find out how the thing was going, not to just CNN, we had a huge spike in activity. We were astounded by how many were people were there. It was a different era in terms of bandwidth, we basically produced a huge spike in Internet traffic, which clogged things up for awhile. At that time it was completely unprecedented, but it gave people a taste of what might happen in the future. Our webmaster single-handedly figured out how to connect all these people, to make our website a success, and make it cool. He's one of the unsung heroes of Pathfinder.”
And so is Rob Manning, along with hundreds of others at the Jet Propulsion Laboratory.
After the failure of the Mars 96 mission, Russia must have felt “Mars Fatigue.” Virtually every mission the Russians had sent off to the Red Planet had met with failure, from outright launch failure to trajectories askew (missing the planet entirely) to landers that failed upon touchdown. In any case, their record could be seen as one of failure perfected.1
However, this is too simplistic. Much has been learned along the way, and one only need look at their successes with the hellhole that is Venus to see that the Soviet/Russian unmanned program has great merit. And, as the old Russian proverb says, “One beaten person is worth two unbeaten ones.”
It is perhaps in this spirit that the Russian Federation approached its cooperation with the European Space Agency's Mars Express mission. Launched in 2003 atop a Russian rocket, the mission included many components of its own failed Mars 96 project. In a bit of technological cross-pollination, some of the technology on Mars 96 had come from Western Europe, so this was not as much an admission of need on the Russian part as a chance for continued cooperation. In addition to the European Space Agency's role, NASA joined the effort, bringing expertise in tracking and control to the table.2
Mars Express derived its name in part due to the extremely short distance the spacecraft had to cover at that particular launch opportunity: in 2003, Mars and Earth were closer than they had been in sixty thousand years. It would not do to wait for the next one. It should be noted that at under $200 million (US), it was also one of the cheapest Mars missions on record.
The probe consisted of two major components: the Euro-Russian Mars Express Orbiter and the British Beagle 2 lander. The lander was a small and fairly simple craft, designed to assess the usual components of the Martian environment—weather, landing-site geology and geochemistry—and even search for indicators of life. Unique to this craft were its origins: rather than the usual government-industry collaboration, Beagle 2 was born in academia. A professor at the United Kingdom's Open University, in association with the University of Leicester, promoted the idea, eventually drawing in two other universities and four industry partners. The final result was a worthy craft, a small “clamshell” probe with a manipulator arm, designed to land via parachute and airbags, not unlike the Mars Pathfinder before it.
The successful orbiter followed traditional concepts, with a central body flanked by solar panels. The instruments onboard were designed to meet an increasingly familiar set of goals:
A spectrometer working in both visible and infrared wavelengths called OMEGA would determine surface mineral composition.
Another spectrometer in the ultraviolet and infrared wavelengths, called SPICAM, was specifically designed for sensing the composition of the atmosphere.
A radar altimeter called MARSIS would seek subsurface water.
A Fourier Spectrometer to measure atmospheric temperature and pressure.
A high-resolution stereo camera could photograph surface features.
And various radio and energy-sensing experiments were also onboard.
Mars Express was also equipped, as were Mars Odyssey and the Mars Reconnaissance Orbiter, to be a relay for NASA's other Mars landers and rovers.
As the craft neared Mars, the Beagle 2 separated to continue along its own path, bound for the planet's surface. It eventually made it, but not alive. So far as can be gleaned from the data, some part of the landing system failed and Beagle crashed.
The Mars Express orbiter was luckier, attaining orbit around the planet in late December 2003. This mission eschewed aero-braking; a small rocket engine was used for slowing and to allow orbital capture. As a result, the craft went into a highly elliptical orbit, 185 miles from the surface at its lowest point and 6,280 miles at its highest. Not ideal for orbital work, but far simpler (and safer) than pursuing a circular orbit.
Notable accomplishments of Mars Express are many. The poles were studied, resulting in a measurement of 15 percent water ice and 85 percent carbon dioxide there. Methane and ammonia were sensed in the atmosphere; this is noteworthy because neither would last very long in the Martian air, so a source of continual replenishment must exist. And that source could be active volcanoes, hydrothermal vents or…living things.3
Of course, water was again spotted, both as current ice deposits and as areas indicative of a wet past. Intensive atmospheric investigations were made, helping to identify the rate at which the air is thinning on Mars. Hydrated (water-altered) minerals were observed at the poles, and similar rocks were spotted in Valles Marineris, which continues to narrow down the time scale of the aqueous episodes of Mars. The idea of a wetter Mars in the distant past, followed by a drier, harsher planet in more recent epochs, as seen in the geological record, was strengthened. Auroral displays were observed above areas of strong magnetic activity. Finally, the lumpy gravitational field was observed and recorded.
The MARSIS instrument allowed for a more direct look beneath the surface of the planet, revealing yet more indications of subsurface water. MARSIS was further able to probe the intricacies of the polar caps, giving a better idea of the total mass of water ice there. The southern ice cap alone has a maximum depth of over two miles, and if melted, it could cover the entire globe to a depth of about thirty-five feet! Finally, a fascinating frozen mass of water was found in the Elysium region near the Martian equator—a place it really had no right to be. And it is young by geological standards—only about five million years old.
Not bad for a seemingly dry, dead world.
The mission of Mars Express has been extended numerous times and continues to this day. The probe returns a continuing stream of images and data from Mars and serves as a valued complement to NASA's own orbiters as well as an outpost of European scientific endeavors. Results from this mission have added greatly to the ever-growing knowledge of the Martian environment and its processes. In particular, the puzzling observations of stray methane in the Martian atmosphere have many researchers intrigued.
Europe and its partners will return to Mars with the ExoMars probe soon, possibly as early as 2016. With good planning and a dash of luck, some of these questions may be resolved.4
It came from nowhere, hid in the darkness, attacked things earthly and then retreated once again.
It was the Great Galactic Ghoul, the monster that hides somewhere between the orbits of Earth and Mars in our solar system, whose sole purpose is to devour unwary spacecraft and plunge earthbound scientists into despair. And the ghoul is good at its job.
Almost forty spacecraft have headed off to Mars. Nineteen have arri
ved intact and functional. NASA's score: thirteen out of twenty. Better than the unfortunate whole (which is heavily weighted toward Soviet-era failures), but grim nonetheless. Had the Apollo program suffered such losses, few astronauts would have stepped up for future missions.
But Mars is not the moon, and traveling to the Red Planet (even ignoring the added complication of taking human beings) is far more difficult and time-consuming. Mars is a killer of probes, a consumer of human capital. And this is perhaps fitting for the God of War.
The origins of the ghoul's name are uncertain; some credit it to a Time magazine reporter from the 1960s, others to various personnel within JPL and NASA. However, one recent mention occurred in 1997 referring to the partial blockage of the Mars Pathfinder's rover ramp by the deflated airbags (the problem was later resolved, and the ghoul was cheated out of lunch).1
Over the years, the ghoul has gobbled up many machines, primarily but not exclusively from the early days of space exploration. A partial list includes:
1960
Mars 1960 A, USSR—Launch failure
Mars 1960 B, USSR—Launch failure
1962
Sputnik 22 (Mars 1962 A), USSR—Broke up shortly after launch
Mars 1, USSR—Lost contact before Mars flyby
Sputnik 24 (Mars 1962 B), USSR—Failed to leave Earth orbit
1964
Mariner 3, US (Mariner 4 succeeded)—Launch shroud failed to deploy properly
Zond 2, USSR—Lost communication ninety days before reaching Mars
1969
Mars 1969 A, USSR—Launch failure
Mars 1969 B, USSR—Launch failure
1971
Cosmos 419 (Mars 1971 A), USSR—Launch failure
Mariner 8, US (Mariner 9 succeeded)—Launch failure
Mars 2, USSR—Orbiter succeeded, lander crashed on Mars
