In August 2012, the most ambitious robotic vehicle ever devised landed on Mars on a mission to probe the Red Planet for signs of past and present habitability. Twelve months on we speak to the team’s deputy project scientist about Curiosity’s accomplishments so far, and what it’ll be doing in the next year
Written by Jonathan O’Callaghan
On 6 August 2012 the world watched in awe as a rover the size of a car descended to the surface of Mars under a rocket-powered contraption and touched down. Almost a decade in the making, the Mars Science Laboratory (MSL), better known as the Curiosity rover, has been a massive success story for NASA. Never before has such a large and complicated vehicle landed on another world.
In the 12 months Curiosity has been operational it has been making some tentative steps towards achieving its numerous goals, which include assessing Mars for signs of past and present habitability. NASA has been careful to only take baby steps so far, but in the next year Curiosity will be pushed to the limits as it explores its surroundings and heads towards its ultimate goal, Mount Sharp (a mountain also known as Aeolis Mons), which rises 5.5 kilometres (3.4 miles) above the floor of Gale Crater and has layers of sediments that may hold clues about the Red Planet’s history.
“When you land you have this incredible burst of adrenaline,” Dr Joy Crisp, the deputy project scientist for the MSL mission, told All About Space. “But a lot of this first year involved [testing] of more and more [of our] capabilities. We needed to test things out on Mars before we went crazy, but now we are a lot more confident in the rover.”
That’s not to belittle any of the accomplishments of Curiosity so far, however. While it may only have taken tentative steps, it has already found evidence of a watery past on Mars and returned stunning high-resolution images from the surface.
The first piece of evidence of Mars’s wet past that was discovered by Curiosity came from “conglomerate rock with rounded pebbles in it,” Dr Crisp explained. “When we looked at those pebbles and saw how rounded they were, that led the science team to be able to figure out how deep the water had to have been and how fast it was flowing. They were able to determine that those rocks were deposited from a stream.”
With groundbreaking discoveries like this already being made, we can expect great things from Curiosity in the future as the team becomes more confident in its abilities.
Since the rover landed, the MSL team at NASA’s Jet Propulsion Laboratory in California have made great strides in their operations to make sure they get the most out of the mission. “We try to come up with better ways to do operations, so we’ve had to make changes along the way to make the whole operations timeline go faster,” said Dr Crisp. “We started out working on Mars time [one Martian day is 37 minutes longer than an Earth day], taking about 16 or 17 hours preparing the rover’s commands for the next day, and we’ve gotten that down to 11 hours now, so we can work more normal hours.”
Considering the complexity of the mission, it’s remarkable that things have gone so smoothly in the last 12 months barring one mishap. “It’s performed very well,” agreed Dr Crisp, “but we did have one hiccup where one side of the computer had an issue, so we had to switch to the other side, but overall everything has been functioning okay. It’s a very, very complicated beast and it takes a lot of effort [for] everybody to understand that complexity and be able to plan what the rover should do each day.”
As mentioned earlier the primary objective of Curiosity’s mission is to ascend Mount Sharp and study the mountain’s various sedimentary layers. However, as Curiosity’s projected landing site was within an area 19 kilometres by 7 kilometres (12 miles by 4 miles), NASA was unsure where exactly the rover would land. Ultimately it touched down just a few kilometres from the centre of this area near a region of particular interest known as Glenelg. So, rather than rushing straight to Mount Sharp, NASA made the decision to explore the flat plain of Gale Crater first, as it will likely not return here in the future.
“Looking at where we landed from the orbiter images we realised it would make sense to first go over to Glenelg and check out these different rocks that we could see before heading over to Mount Sharp,” explained Dr Crisp. But while the lifetime of the rover was set at a lowest estimate of two years, “if it’s anything like Spirit and Opportunity this rover may last much longer than two Earth years,” which gives Curiosity plenty of time to study Mount Sharp. In fact, NASA recently extended the operational lifetime of the mission indefinitely, giving the MSL team funding to continue driving the rover until it stops working, which could be several decades from now.
Aside from observing pebbles in an ancient streambed, indicative of a wet past on Mars, Curiosity has also been testing out its other instruments to ensure they are working normally ahead of some planned hardcore science for the rover. “We’re looking for past environments that could have been suitable for life,” explained Dr Crisp, “and liquid water is key for life as we know it. So getting over to Yellowknife Bay [a Martian outcrop in the Glenelg area] and drilling into sedimentary rock and discovering abundant clay mineral, which has a lot of bound water in it that can only form in the presence of liquid water, was a major find.”
Not all of Curiosity’s instruments have returned data with such a high level of interest so far, though, but of most importance to Dr Crisp was ensuring that “the instruments were working well.” One of the most important instruments on the Curiosity rover is SAM (Sample Analysis at Mars), a suite of instruments comprising over half of the rover’s scientific payload that can scoop up soil samples and analyse them in an on-board laboratory. “We sent the SAM instrument to look for organic compounds,” said Dr Crisp, “but we knew it was going to be like looking for a needle in a haystack. It’s not easy to find organic compounds preserved in ancient rocks even on Earth, so we didn’t really expect to hit it on the first try.” SAM, however, will undoubtedly prove to be one of Curiosity’s most valuable assets when it comes to studying the sedimentary deposits on Mount Sharp.
With the first year now behind them, the MSL team are eager to really get the wheels rolling and make use of Curiosity as best they can. According to Dr Crisp, in the next 12 months “we will be driving a lot further than we’ve done so far, heading towards Mount Sharp, so we don’t know what exactly we’ll encounter or what we’ll see from our cameras on the surface. We can see from orbit that we might want to stop a handful of times on our way to Mount Sharp but we don’t want to get bogged down unless there’s something really amazing that we discover on the way. So [in the next 12 months] we’ll be doing a lot of driving, and if you’ve seen the pictures of Mount Sharp with the layering it looks really fascinating. So I think that will be a magnetic pole for our team to psychologically want to keep going, because as we drive the detail of what we can see in those hills is going to get more and more interesting.”
While Curiosity’s predecessors Spirit and Opportunity (of which only the latter is still operational) have travelled tens of kilometres on the surface, never before has a rover attempted to scale a mountain on Mars in the way Curiosity will. But, as Dr Crisp explains, the team believes the rover will have no problems making its way to a higher altitude. “The wind should not be a problem,” she said, “and it’ll be interesting for the meteorological instrument to measure that. The steepness we believe will also be okay, based on studying the 3D models we have from our orbiter data. When we actually get there and see the terrain up close our 3D models will improve and we may have to adjust our routes based on that newer data as well as finding out how much the rover slips on different kinds of rock.”
So, with the most exciting part of Curiosity’s mission yet to come, Dr Crisp highlighted a “combination of new things” that will be of most interest to both scientists and the public alike in the coming year. “I’m hoping that we’re going to see some new rock types and new landforms that tell us about other things that went on in the past on Mars,” she said. And with the public clamouring for more astounding science and incredible imagery from Curiosity, the rover’s mission will only get better and better as the team becomes more confident in their operation of one of the greatest and most ambitious space exploration missions of all time.