Designing for the Challenges of Operations on Mars
The other day, Motiv’s VP of Business Development, Tom McCarthy, appeared on WDUN to talk with Bill Maine about the challenges and accomplishments of the Mars Perseverance Rover’s robotic arm.
Some of the biggest challenges McCarthy brought up? Protecting sensitive equipment from strong Martian winds and dust, and designing equipment to survive temperature swings that can go from 70°F during the day to -100°F at night.
Not only is Perseverance Rover’s robotic arm designed to handle tough conditions on the surface of Mars, it’s also the most advanced we’ve ever sent.
As McCarthy said, “Each mission gives us another level of capability and sophistication. And this follows in their lineage.”
The pair also discussed the ability of the Perseverance Rover’s robotic arm to carry and manipulate heavy payloads, like the drill that will be used to collect samples of the Martian soil, and more.
Listen to the entire interview below.
Bill Maine 0:02
Let’s make a trip to Mars, shall we? We’re checking in with Tom McCarthy, who joins us now from LA. He’s an engineer with Motiv. You guys did some really big things that are now on Mars, sending back some incredible pictures. Talk about that new camera.
Tom McCarthy 0:48
The Mastcam-Z sits right below the head of the rover, and it has two of the cameras that are bringing back those incredible panoramic views. It’s the first time they’ve had cameras with a zoom and focus capability working together. You’re getting full stereoscopic 4k immersive imagery – and it’s awesome. The stuff that’s coming back is just incredible.
Bill Maine 1:21
What are some of the challenges in designing something like this, when it’s going to be in an environment where you physically, personally haven’t been?
Tom McCarthy 1:30
As you’ve been hearing the sounds from Mars, you can infer that there’s a lot of wind motion, and that means there’s a lot of dust flying around. We have to make sure those cameras are sealed appropriately, so that we don’t get any fine dust in there that would affect the ability of the mechanism to work, or hurt the imagery process. Also, those cameras have to experience some incredible temperature thresholds from night to daytime. The camera has to survive, and it gets really, really cold. During the day, it warms up, and that huge temperature swing is something that you have to design for, to make sure there’s plenty of compliance in the system – so that it holds together well and operates correctly.
Bill Maine 2:23
With all that dust getting into the camera, it could grind down a lens, or the cover on the lens. How did you address that?
Tom McCarthy 2:35
The baffling is built to provide enough shielding to the camera – the lenses are far enough back – and they’re prepared for that environment. Historically, we’ve always gotten great imagery back from Mars. Each mission gives us another level of capability and sophistication. This follows in their lineage. For months, and hopefully years to come, we’ll have incredible video being put together, to really give you that experience – like you’re standing there.
Bill Maine 3:13
Let’s talk a little about the other object that’s on there, that other piece of gear – the arm. I would imagine the basic design of that is probably not a challenge, but you’ve got to be able to remotely control and understand what’s going on.
Tom McCarthy 3:33
The arm is a sophisticated piece of equipment. At the end of the arm is the turret, which carries all the science instrumentation – cameras that use different wavelengths for looking at the soil or looking at the rocks before deciding to take a sample and do a coring operation. There’s a big coring drill on the end, with a payload of 45 kilograms – and the arm is about six to seven feet long. Imagine trying to hold a bag of concrete straight out, and perfectly positioned, while you’re doing your work. There’s a lot expected from that arm. It also has a sensor at the end that gives it a sense of touch. It can go out and collect samples, and then bring them back to the rover, and ingest them for later encapsulation.
Bill Maine 4:32
Are you starting to tweak it for future use? Are you pleased with the way things are going?
Tom McCarthy 4:43
We’re extremely happy with how everything is going. There’s a number of sequences that take place, where the arm has a number of locks for protection during launch. On landing, those all get released, and the arm comes out of its locks. The big thing is to make sure everything arrives safely, and that the arm is able to free itself from its locked configuration, and go about its science duties, to pick areas for sampling.
Bill Maine 5:21
You’ve got to be thrilled to be part of this. But also, you’re designing this as a long-term project. It’s not like you design it, pop it on the thing, shoot it up into space, and find out immediately if it’s going to work or not. It’s a lot of holding your breath, I would bet.
Tom McCarthy 5:38
Right. It took us a few years – and it’s a big team of people. We represent the engineers, technicians, and project managers that came together to do this. Plus, we worked with all of our colleagues at JPL, where they’re constantly adapting the design of these arms. It’s been an incredible journey – and it’s always surreal. For so long, the arm was sitting there in a cleanroom inside our facility – we saw it every day. And then it’s gone. And the next time you see it, it’s on another planet. That’s a pretty fun experience.
Bill Maine 6:44
All grown up and out of the house. I want to find out more about what you guys are doing at Motiv, and about this particular project. I’m sure you’ve got some pictures online – things we can check out.
Tom McCarthy 6:57
You can go to motivss.com – we do all sorts of things in space. We’re a part of an exciting, growing community, doing things for science and exploration. Hope to someday be on the moon. Lots of things going on.
Bill Maine 7:18
The big question that everybody’s gonna be asking after this interview, about those cameras – when can we get that on a cell phone?
Tom McCarthy 7:27
It’s probably sooner than you know.
Bill Maine 7:30
Everybody always cares about new cameras on the cell phone. “Can I take a picture?” “Let me get a selfie.” Tom McCarthy, you’ve got a great job and a great sense of humor. Best of luck to you.
Tom McCarthy 7:42
Thank you very much.
Learn about all the details of Motiv’s contribution by visiting our mission page for the Mars 2020 Perseverance rover.