Mars sample return has been a high priorityfor the scientific community for a long time. The dark comedy sort of joke has always been thatMars sample return is 10 to 15 years away, no matter what year it is. So here we are,we actually have a mission, it’s built, it’s sitting at the Cape, it’s getting ready tobe launched.
That will be the first stage in returning samples from Mars. It’s justhuge. It’s an Apollo 11 type mission, because of the unique properties of Mars, becauseof the whole question of, “Has life ever existed anywhere else?” All of those things are allwrapped up into this particular mission. The question of whether any environments on Marswere habitable or are habitable today is really what drives things.
There’s this remarkableglobal climatic change that occurred right around three and a half to four billion yearsago on Mars that took it from a planet that probably was habitable to something that’sdesolate and dry and irradiated at the surface with a thin atmosphere now.
The really interestingthing is to do this comparative planetary geology to say, well, why did the Earth evolvethe way it did with abundant life? And why did Mars evolve the way it did in its ownunique way? To find answers to these questions, scientists use orbiters, landers, rovers,and recovered Martian rocks that can survive the trip down to Earth. I’m sitting in theUniversity of Alberta, Meteorite Curation Facility.
It’s a lab that I built and designed,where we have a clean room, which you can see over my shoulder here. It’s the sort ofglassed in area and the rock cabinets in there have about 1800 specimens of different meteoritesfrom around the world. The Martian meteorites are a unique set of rocks that have been blastedoff the surface of Mars, naturally.
There’s 140 or more meteorites and over 80% of themare basically lava flows that float out on the surface of Mars in the last few hundredmillion years. Now Mars is four and a half billion years old. So there’s a whole historythere that’s missing because of a bias in the way that these samples are delivered tous. And that’s what makes this upcoming launch an ambitious new chapter in Mars exploration.
It’s the first step in a series of proposed missions over the span of a decade to bring samplesback, with all of the source material. The idea is to go to a place where the rocks areof that age of at least three and a half billion years, so that we can probe those for evidencefor ancient life.
The landing site is Jezero Crater. It’s a remarkable 45 kilometer diametercrater that was filled with water, had a river flowing into it and a river flowing out ofit in a key timeframe in Mars’ history. There are mineral signatures that have been detectedfrom orbit, including carbonate. And carbonate is a mineral that life can sometimes use,as part of producing, say a hard shell. Those rocks are beautifully preserved.
You can seethem from orbit. And that’s the real reason why this was chosen. The whole idea is toget a cache of samples that are so compelling to the scientific community, that the spaceagencies could do nothing less than spend the money to basically bring everything back.
That’s a tall order for this new rover, but luckily, NASA’s engineering teams areexperts at building capable robot geologists. Mars 2020, the advancement is adding the samplecaching system. We have a bit carousel that holds all of our various bits or tools thatwe have for working on Mars. We have a five degree of freedom robotic arm that’s on theoutside of the rover that allows us to not only dock for tool exchange but also for placingsome of the science instruments.
The drill is able to not only be the jackhammer whereit actually takes out the sample from the rock, but it’s also able to do very delicatetool drop-offs. It’s a very complex system. This is the inside of Building 248 on theNASA JPL campus. It’s where Eric and his team put the sample caching system to thetest. So in order to really make sure that the system’s going to work, we always tryto emulate the environment that we’re going to work in.
We have a Geo analog team thatallows us to collect rocks something approximately close to what we might see on Mars. We createdthis unique test setup, where we’re able to be in a thermal vacuum chamber, that allowsus to get down to the Mars pressure.
We have to make sure that we’ve learned how to getthe teeth of the drill just right to get a sample. Our testing over time has been aniterative process that helped us design a better, more reliable sampling system. The targeted launch window for this rover is July through Aug 2020, with a landing date of February2021.
After it survives the trip to Mars and sticks the perilous landing, the roverwill take some time to get situated. There’s usually a commissioning period It’s been along ride and everything’s just kind of unfolding and getting itself ready. At that point,they want to start taking advantage of where they’re at. Where did we land? What can wesee? The main approach is to look at a region of interest do a walkabout.
We havecameras that are able to get the mineral signatures of rocks. We have the super cam, which is essentiallya laser that can zap the rocks a few meters away, and tell you what they’re made of, whichI just love that. It’s fantastic. That one has a microphone attached to it now too. Sowe’ll be able to hear the rocks getting zapped from a distance which is pretty awesome.
Thereis going to have to be a certain balance between the desire to completely explore and thendecide from there what samples you’re going to get. We’re trying to keep everything withina one Martian year, which is about two years Earth time to get all the samples collected. Thereis a pace that the science and operations team are working to.
There’s 43 tubes 37 isthe number that we expect to bring back. Our job is to put a sample in every tube and thescientists will have to choose which ones to leave behind. So we hope to give them areally tough decision. I’m really looking forward to those conversations when we’redoing the mission operations.
We’ve got a bit of a hint of it a couple of months ago,when we were all working remotely on a simulated rover mission, where the folks from NASA JPLwent out to the Nevada desert and set up a bunch of instruments, and made it look likethe Rover was there. And the discussions about what to sample were absolutely fascinating.Something that would be really compelling would be like a mudstone, like a really finegrain rock that was deposited within the delta, that has lots of organic matter in it. Anotherreally compelling thing, of course, would be these carbonate rocks.
So this whole discussionabout, would you, should you collect that particular sample, or should you explore more. Aftersome careful decisions, the rover will start caching. Once we’ve taken a rock from theground and it’s in the tube, the sample handling arm, inside the belly of the rover will actuallygo and pull the sample out and start to process it.
The autonomy that’s built into the systemis fairly incredible there’s a lot of closed loop motor control activities. Once we actuallyexpose a sterile tube to the Martian atmosphere, we have a five hour timeline to actually getit sealed. Contamination is a critical part of our mission. We don’t want to take anyorganics with us. This is something that feels like a Sci Fi movie but it’s reality.The plan is to drop off the samples in bunches around Mars where a future mission would landand use a fetch rover to go and pick them up.
They’ll be installed into a Mars ascentvehicle, which will then launch off of Mars into a Martian orbit where another missionwould come rendezvous and pick up the sample. And then that orbiter would then turn back andhead back towards Earth. The current plans are for the samples to be returned to Earthin 2031.
There’s a small, but non zero chance that there is extant life that could comeback with the samples. And so that’s where the other part of Mars sample return is reallyimportant, which is the sample receiving facility.
And then the design of that is going to benext level kind of stuff though, because the same time that we’re trying to keep whateveris in the samples from getting out into the Earth environment, we’re also trying to keepthe Earth environment from getting into the samples. I’m one of 10 people selected asa Return Sample scientist, through a NASA call. These are all people, like myself, whohave experience in the lab with samples of meteorites.
You know, age 13, I think, Isaid I want to be there when the samples come back and it’s a dream come true to reallybe involved as a return sample scientist, as someone who is an expert in what you dowith the samples when they come back. I sure hope I’ll be able to see them. I’m going tohave my favorites. They are going to be curated under the best possible conditions and preservedindefinitely for generations to come.
Each one of those will be scrutinized like youwouldn’t believe, the way that all the Apollo samples have been scrutinized for 50 or moreyears, now with the added bonus, of course, that we’re actually going to an environmentthat could potentially have been habitable.
To hopefully answer the big question: wasthere life on Mars? I don’t really have a good answer for that but another way to lookat that question is to say, well, if we don’t find life that’s a significant step towardunderstanding what life is all about. And how unique it is, for example, for the Earth. Onthe flip side, if we do find evidence for ancient microbial life it just opens thatdoor to life being incredibly abundant throughout the whole universe on these almost infinitenumber of planets that are being discovered in our galaxy and beyond.