Home > Features > Walk on Mars
Walk on Mars
An FWR exclusive with Jim Erickson, Mars mission manager
By Michael Summers
Fort Wayne Reader
“It’s sort of like when you plan a trip cross-country,” says Jim Erickson. “You first plan out your route — you’ve got a map, you’re seeing where the cities are and where the gas stations might be, and you plan where you want to go. You get to your first stop, and it turns out there’s a detour. So you take the detour, and it happens there’s a really interesting tourist sight there, so you stop there for the day. You adjust back to the plan eventually, but in the meantime you’re sort of having fun along the way.”
Well, sure, it’s sort of like that, except the journey Erickson is describing isn’t a family trip from, say, Ohio to the Grand Canyon, and the interesting tourist spots along the way aren’t ghost towns or amusement parks. It’s the day-to-day operations of the Spirit rover, and its route takes it across the surface of Mars.
Jim Erickson is one of the key members the team of engineers, scientists, and technicians we saw on the evening news breaking out bottles of champagne at the rovers’ successful touchdown. He was responsible for getting Spirit and Opportunity to Mars and on the surface, and helped design the ground system that is being used to operate the rovers.
After a seven-month journey, Spirit rolled off the lander onto the Martian surface, a plaque memorializing the crew of the Columbia on its high-gain antenna, and began a proposed 90-day mission to collect and study geologic samples and determine whether conditions on Mars were ever suitable for life.
Mars mission control was riding high with the success of the Spirit rover. After two embarrassing public failures in the late 90s, including the infamous measurement system mix-up with the Mars Climate Controller, the Mars program was once again in the public eye — favorably. The latest findings of the Mars rover lead on the nightly news and captured the headlines, while President Bush proposed budget increases towards a manned mission to Mars in 2030. Best of all, we were treated to a series of incredible photographs, the most detailed images seen yet of the red planet. Cynics can joke that it looks like Death Valley. It’s not. It’s Mars. No other bright dot in the night sky has captured the imagination of Earthlings like the red planet, and with Spirit we were seeing it in more depth, resolution and color than anyone has ever seen it before.
A week or so later, things didn’t look so rosy. Spirit stopped sending signals — no images, no data, nothing. All the JPL could get from it was a beep, essentially just a radio signal that says “I’m here.” It was enough to indicate that the computers were working, power was adequate, software was in good shape, but something was obviously wrong. On top of that, JPL had to contend with the second Martian lander, Opportunity, touching down on the opposite side of the planet at Meridiani, a broad, flat plain where there is a mineral that seems to indicate that liquid water was once on the surface.
Spirit’s landing had been described as “near-perfect,” and according to Erickson, that wasn’t an exaggeration. The biggest surprise of the mission so far was that everything had gone so perfectly. “Within ten minutes we got our first signal that the rover had stopped rolling on the surface and was going to unfold and get ready. We had lots of scenarios for what we would do if this didn’t happen or that didn’t happen, and we didn’t have to go down any of those paths.”
Opportunity was landing in a completely different environment. Meridiani is higher than Gustev Crater where Spirit landed, so the lander would have less distance to work with from top of atmosphere to the ground.
Erickson describes some of the odds involved in a project like this. “Only about 1 in 3 missions to Mars has worked, and part of the problem is the fact that you have to have thousands of things that all work right,” he says. “It isn’t like if half of them work, you’ll be okay. For example, there are 64 different pyro events that all have to work perfectly before the rover will actually come to a rest on the surface and unfold. Yes, we have redundancies on each of those 64 pyros, so we have two chances to make it work, but we still have to have every single one of those 64 functions work. A single one not working, and it’s over. And that’s just in that one particular area. We have motors that have to open the solar panels (the rovers are solar powered), we have other motors that have to open up the landing panels, we have parachutes that have to come out… It’s not like you can drop test a bunch of them in the Martian atmosphere and pick the one that works the best. You have to work the first time, every time.”
Erickson says that the days Spirit was silent and Opportunity was preparing to land were tense ones at the JPL, but he describes the overall mood as focused. “If you’re in there working, you don’t worry about the other issues,” he says. “Roll up your sleeves, put your head down, and get in there.”
Putting his head down and focusing are all Erickson really has time for these days. Opportunity landed successfully, and Erickson’s duty now includes surface operation of the new lander. Basically, he’s going to be telling where to go and what to do. With Spirit now transmitting and Opportunity off the lander and on the surface of Mars, Erickson and Jennifer Trosper, (Spirit’s mission manager for surface operations) have a whole other set of potential problems to consider. “We’re worried about something we don’t notice at the time,” Erickson says, talking about Spirit. “Say there’s sort of circular, dusty depression. Is it a crater that’s filled with really soft sand? If we drove in it, would we sink? We use mini test images, scan across that, and see if the scientists can tell us something about how thick the layer of dust is there before you hit a solid surface. If we really needed to go into this area, we’d probably drive up to it, poke one wheel into it, spin the wheel, and see if there is firm soil underneath the dust. We’re by nature kind of paranoid when we have a priceless asset on Mars, but at the same time if we’re not bold we’re not going to able to get the kind of science results that justify the hard work and effort that’s gone into this.”
Dipping a wheel in a crater of sand? Spinning it around to see if there’s solid ground underneath? It’s good to be reminded that the vehicle he’s talking about isn’t a remote controlled toy in a sandbox but a mind-bogglingly complicated piece of machinery operating millions and millions of miles away on a different planet. But though there is an overall strategic plan for the Mars rovers, there’s a lot more flexibility and day-to-day planning than one might expect. The mission managers and their teams operate in shifts — two teams per rover, working 10 – 12 hour days, four days a week (“with three days off to collapse”). “The vehicle is very day-to-day centered,” explains Erickson. “Very tactical. Basically, everyday the science team decides on the basis of what they saw yesterday what they want to do tomorrow. We listen to their science desires, we make sure that the commands are built to accomplish those tasks and that the vehicle can do them without damage or risk. Then we send them up to the vehicle and make sure they’re executed. We hand the results back to the science team, and they plan the following day. It’s very interactive.”
Even before the glitch with Spirit, the president’s plans for Mars met with considerable skepticism. Many analysts see it as a cynical election-year promise, that it’s pretty easy to commit yourself to a manned trip to Mars when the date is 2030 at the earliest. Others point to the fact that an increase in NASA’s budget would primarily benefit Florida and Texas.
Another problem is the cost. Bush has proposed spending $12 billion over the next five years towards these plans; only about $1 billion of that includes an actual budget increase for NASA, while the rest of the money would come from re-structuring other NASA programs. $12 billion is nothing to take lightly, but some in Congress believe that even that is not enough to do the trick. And still others wonder whether the money wouldn’t better be spent on domestic programs (NASA’s budget is about 1% of the federal budget).
Erickson has worked at JPL for a long time — nearly 30 years. He started while he was still in college, where his job was producing some of the photographs that came down to Earth from the Viking lander. Later, he worked on Voyager and Galileo. For someone involved in so many ambitious, high-profile space programs, Erickson seems to choose his words carefully when asked what he thinks about the president’s proposal. “I’ve been keeping my head down, so I haven’t read many of the news reports on this,” he says.
And what about a manned flight to the moon and then to Mars? Erickson firmly believes that technologically it’s possible, but is well aware that such an endeavor takes more than technology. “I’m more familiar with the robotic aspects of space exploration. A lot of this has to do with first robotics, then the manned exploration later on. Now, I’m sure the details will change as we proceed, but just being committed to something like that in the first place is what’s going to drive a lot of this. We have to decide we’re going to do it, and then we can do it. The people at JPL don’t work here for the money. It’s for the excitement of doing space exploration. The fact that the country might be committing itself to bolder steps, and further the exploration of space in a major way, means much more exciting time for my kids and our grandkids. So I feel I’ve had my time, and it looks like maybe there’s going to be exciting times for future generations as well.”
The problem with Spirit came out of the blue, according to Erickson. Technicians at the JPL examined all the data leading up to the sudden failure, and found nothing that might indicate something was wrong. “The leading theory is that the organization of memory on Spirit, which we call ‘flash memory,’ just like a digital camera, seems to have a problem,” says Erickson. Opportunity is also having problems. The rover’s heater won’t turn off when JPL tells it to, and the only thing keeping it from being on all the time is Opportunity’s thermostat. Spirit is well on the way to recovery, and has begun transmitting data and images again, and Erickson is confident that Opportunity’s heater problem can be solved or worked around, and won’t prevent the rover from fulfilling its mission. Still, both problems serve as a reminder of the potential dangers of such a complicated operation. “You’re not going to have a complete mission that has absolutely no problems whatsoever,” Erickson says. “We were going really well. I guess we all should have knocked on wood a little bit, but that’s just the way these things go.”
In fact, Erickson sees no reason why the earlier, optimistic predictions for Spirit and Opportunity can’t still happen. “I’m interested in seeing where we’re going to be able to drive to. With Viking 1 and 2 and Pathfinder, we’ve got three different places we’ve been to on Mars. These rovers should be able to more than double that in terms of their lifetime, their ability to drive hither and yon…” Erickson thinks the two rovers can go a lot further, and last a lot longer, than the current mission calls for, but he won’t make any specific predictions. Whether or not the rovers are successful in their ultimate mission — discovering evidence of water on Mars once upon a time — doesn’t seem to be of primary importance to Erickson. The fact that Spirit and Opportunity seem able to overcome their technical glitches and perform their mission seems success enough to Erickson for the moment.
Only time will tell whether the president’s proposal becomes a reality, or is continued by future administrations. But move beyond the politics and the questions of “what’s next,” and you’re left with some pretty remarkable images. When asked how it feels to be able to look at a red dot in the night sky and know that something he had a hand in designing is up there right now, Erickson, a veteran of America’s space program for nearly 30 years, is still capable of the same amazement as many of us feel as we look at the latest pictures from Mars on our computer or TV screens, and just as lost for words. “About as great as you might expect,” Erickson says. “It’s just one of the cooler things I’ll ever do in life.”