M arried to another JPL scientist, Joy Crisp can be found on off hours at her Princeton home quietly immersed in a science fiction book, often a David Brin title. She has been at work on the Mars Science Laboratory for years, acting as the deputy project scientist, but her path to Mars was not a simple one.

“I was a volcanologist, so I studied volcanoes on the Earth. I was doing a postdoc at UCLA, and a friend of mine said ‘I think there are people at JPL that are volcanologists, and there might be a postdoc position open there.’ I had no idea! I thought JPL was just a place where they studied space. I talked to them and sure enough they were using thermal infrared sensors to look at Hawaii. I started to do research at JPL with a group of people, and then Pathfinder came along and they needed someone who could work on the instruments like the APXS [alpha proton x-ray spectrometer], which measured the chemistry of rocks and minerals, and they said they needed someone that knew about geochemistry. I was one of the few people that had that expertise, so I got involved and it was interesting. I moved to the Mars Exploration Rover project, and now I'm on Mars Science Laboratory. So I transitioned from studying volcanoes on Earth to volcanoes on Mars, and I ended up doing all kinds of projects.”1

Of those projects, the Mars Science Laboratory is easily the largest to date.

“This is a very big project, so there's a lot of things to do. We must make sure the science team can carry out their investigations, keep an eye out for the things the engineers are doing that could affect science, and advise a project manager when he has to make decisions.

“[MSL] really is a stepping-stone beyond missions like Pathfinder and [MER], which were very geology focused and didn't really have any capability for looking at organic compounds and the building blocks for life. [The] Mars Science Laboratory is better equipped.

“Pathfinder was a technology-demonstration mission. It was a short-lived mission and we confirmed a lot of things we knew about Mars. We did measure some slightly higher silicon composition, so there were some ground truths right at the site where we landed. Spirit and Opportunity were a huge step in understanding because they were more capable, and because they lived so long. Opportunity is still going, and because of that, we've learned a tremendous amount at two very different sites. One thing that those rovers have done is to show us that there is definitely a diversity of geology on the planet and that we can redirect [the rovers] and find evidence of past water. With Opportunity, we found some rock layers where water was even flowing on the surface, depositing the grains, and also secondary water, ground water, was circulating through them, and cementing them, and making those little hematite spheres in them. So there were lots of clues.

“What we will really be able to do much better with Curiosity is to identify the minerals. We were struggling a little bit with Spirit and Opportunity; we could identify iron-bearing minerals with the Mössbauer spectrometer, but with other minerals, we had to guess somewhat. [We took clues] from a thermal infrared spectrometer as to what mineral combinations might be there. So when we get there with our x-ray diffraction spectrometer on Curiosity, we'll have a much better way to say what minerals are present in the soil and in the rocks that we look at.

“We're also bringing the instrument called SAM, Sample Analysis at Mars; and that one will be able to drill into rocks and find out [if any] organic compounds are present. We haven't tried to do that since Viking days, and when Viking tried to do that, it couldn't find any organics in the soil. We're going to have a more sensitive instrument. We'll be able to heat [the soil] up much higher and be able to look for organics at even a lower level and look at drilled rocks. It's still going to be pretty hard, and it's a remote possibility that we're going to find organic compounds on Mars, but we'll certainly have a better chance of doing it with this rover.”

The MSL rover is not designed to search for life, though. It will search for the basic elements that can support life: “We're not trying to do what we did with Viking, which was to look for life. [With Viking] after we got the experimental results, we scratched our heads and realized that we could think of a way for an inorganic substance to create those kinds of results. That wasn't the best test, and we realized how hard it would be to devise an experiment to look for life. We don't have an instrument that the science community can [agree on] to go look for life. So we're kind of taking a baby step in that direction, going slower than Viking tried, saying ‘let's try to find the organic compounds and measure those again in a better fashion.’”

So…is there life on Mars? The answer is unclear, but Crisp can hazard a guess: “We believe it's more likely that there was life in the past than life today because of the harsh environment today, but we're still going to go and…drill into a rock five centimeters [(two inches) to see if we] find organic compounds preserved in the rocks. We're trying to use techniques that we use on the Earth to look at the rocks and say ‘which one of these are most likely to preserve evidence of organic materials?’”

To collect these samples, MSL will use traditional, tried-and-true techniques, such as a sampler arm with a scoop and rock brush. But there is a new wrinkle in the mix: the rock drill. And getting powdered rock from the drill to the onboard lab in the rover will be yet another challenge: “This is a huge new challenge that we have not tackled before. We did a little bit of this with Phoenix, where they had us scoop and deliver material into an instrument with the wind blowing. We learned a lot of lessons from [that mission], but we're trying something even harder with the rock drill.”

It's natural to assume that it must be frustrating for geologists like Crisp to work from so far away. To this, she responds: “Well, I'm a geologist, so I like to go out with a rock hammer and hit rocks and look at them. I want to know things like how did this rock form, what was it like when this rock was forming or altering, and so on. MSL is just the kind of mission that excites me; it's as if I could be there, because I'm drilling in the rocks, and then I'm finding out what minerals are in it and looking at it with a close-up camera. And this time it will be in color and higher resolution! In all of our sites we have layers of rocks so we can move through and see how things changed over time in Mars, so that's going to be interesting too.”

But still…commanding a machine millions of miles away is far tougher than doing it yourself. And the team must be trained extensively for this: “We had a science team test where we sent some people out to Arizona. It was a site that the team didn't know [the location of], and we set up a bunch of equipment that was like what we were putting on the rover. We started out by taking pictures and we put it into their planning tools. Everybody was working from their home institution around the world, and they started out with a bunch of pictures, and we told them, “here's your picture from orbit, you are here, it's day number 235; now start planning tomorrow and here's what you were thinking of doing.” Many of them have never done this before. A few of them were from the Spirit and Opportunity missions, but many of them had no idea what it would be like.

“One of the lessons learned was that we had no idea how frustrating and challenging it would be to do field geology so slowly. When you are planning the next day's work, you have to argue with your peers on what steps to take. For instance, will the rover drive this way or that way, put up its arm or not, and so forth. We wanted those kinds of lessons to sink in so that they start getting used to it. Personally, after so many years of doing it myself, I just mentally accept that this is how it works. I'm very patient.”

So, given all this, would she prefer to go do it on-site?

“I wouldn't want to go to Mars myself yet because I'm just not ready to do that, it would be way too difficult right now. So I'm willing to do it this way, slowly, via computer. It's a different kind of challenge…can you work with your scientist friends to come up with the best plans to get the rover to do things, and then sift through that precious data to get the most out of it that you can. It's just a different kind of challenge. Like I said, I'm a patient person.”

And, as we know, patience is a virtue rewarded in planetary exploration. The secrets of Mars await.