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NASA Is Testing a Manned Vehicle That Will Explore the Martian Moon Phobos

It's impossible to drive on Phobos, and it's not going to hover—so what's this excursion vehicle going to look like?
Phobos's Stickney crater. Image: NASA

NASA isn't sure, exactly, when it's going to start planning a manned mission to Mars. But NASA astronauts are already doing crewed simulations of what a piloted vehicle explorer would look and act like on Phobos, one of the Martian moons.

Phobos is an odd moon. It's positively tiny, having a radius of just 11 kilometers. Because of its small size, it's more potato-shaped than spherical—there's not enough gravity to force the whole thing into a sphere.

But Phobos is a tantalizing place for a NASA mission. Its complete lack of atmosphere makes it easier to land on than Mars itself, and, as Buzz Aldrin has pointed out many times, it would make a good base station for any sort of human colony on Mars itself.

A support team could set up shop on Phobos and could then act as a communications middleman between Earth and Mars, which would significantly reduce the amount of time it takes to send a message from a Martian colony to Earth.

So, if NASA is going to go to Phobos first, it's going to need a way to explore the moon. And the agency has decided that a standard rover probably isn't going to work. The moon's lack of gravity makes it basically impossible to "drive" on Phobos.

"It would be an excursion vehicle from a larger transfer vehicle that's in Martian orbit."

"We're doing simulations for how it is to operate vehicles on the surface of Phobos. It's an interesting environment," Michael Red, chief of NASA Johnson Space Center's simulation and graphics branch, told me. "Phobos is not completely spherical, has irregular shape, which gives it an interesting gravity model. It doesn't take much to separate yourself from the Phobos environment."

"It's also so close to Mars, you're affected by the Martian gravity," he added. "It changes what you're looking for—we're looking at types of vehicles and propulsion systems about how you would move around Phobos. There's not enough gravity to drive a rover around it, not enough traction or friction. There has to be another option."

Red's simulation center at Johnson Space Center is focused on solving these kinds of problems. While NASA does simulations of all sorts throughout its various branches, Red's center is singularly focused on human spaceflight and training astronauts with the skills they'll need to, say, operate a robotic arm on the International Space Station. There are virtual reality simulations and spaceship piloting simulations that are used today.

And then there's the far off stuff, like the Phobos vehicle simulator.

Red is hesitant to tell me what the Phobos vehicle will look like, because he doesn't even know yet. When I asked if it will have wheels, he said he wasn't sure.

Instead, his center uses three large domes (one is 24-feet tall) to test mockup vehicles in different simulated environments.

"What it would look like is not as pertinent right now as how it would respond to a crew input. We're modeling a kind of control system to look at what it would take to move the vehicle, we have a theoretical math associated with it. It's all real conceptual right now," he said. "And this is just seeing how it's work—you may have a lot of windowspace to allow a large field of view, but then by the time you get to building the thing, you have to pressurize it, and that's a challenge with lots of windowspace. It typically shrinks down real fast, so I hesitate to put too much credence into what it looks like—it's so far out in the future."

That seems fair. But, seriously, Red and his team must at least have an idea of what such a vehicle might look like. So, I pressed him a little bit more:

"OK, it's all very conceptual, but if you think about a human mission, it's got to be some type of excursion-like vehicle. Imagine if you went camping, you'd have a smaller vehicle to look around the terrain," he said. "It's that kind of concept—you have a 3-4 person crew, it has its own environment, propulsion and power. It would be an excursion vehicle from a larger transfer vehicle that's in Martian orbit. You'd want to retain a lot of your propulsion and keep weight down. The type of propulsion we're looking at, it's not a hovering type thing, but it's something that you'd want to be able to take advantage of the environment and gravity model."

I, for one, am ready to see this non hovering, non-driving spaceship excursion vehicle. Hopefully sooner rather than later.

Perfect Worlds is a series on Motherboard about simulations, imitations, and models. Follow along here.