Hello, friends! Welcome to Our Place in Space: A to Z! For this year’s A to Z Challenge, I’ll be taking you on a partly imaginative and highly optimistic tour of humanity’s future in outer space. If you don’t know what the A to Z Challenge is, click here to learn more. In today’s post, P is for…
PHOBOS
Buzz Aldrin. He walked on the Moon. He also has ideas about how to get humans to Mars. We talked about one of those ideas earlier this month, and now we’re going to talk about another. What if, rather than going straight down to the surface of Mars, we first set up a little base for ourselves on Phobos, one of Mars’s two moons.
Whenever you want to land on a planet (or a moon), you’ll have to fight against gravity to do so. That is assuming, of course, that you want to land safely. Crashing into a planetary body is fairly easy. Landing safely—that’s the hard part! You need to control your descent. If you’re controlling your descent using rocket engines, you’re going to use up a whole lot of fuel in the process.
But as you can see in this highly technical diagram, Phobos is very small.

Okay, maybe not that small. But still, Phobos is much smaller than Mars, and Phobos’s surface gravity is significantly less than the surface gravity on Mars. That means a rocket controlled descent onto the surface of Phobos will use up less fuel than a rocket controlled descent all the way down to the surface of Mars.
In his book Mission to Mars: My Vision for Space Exploration, Aldrin argues that we should set up a way station on Phobos before attempting to land humans on Mars. From this Phobos way station, astronauts could get an up close and personal view of Mars. They could get the lay of the land without actually landing. Using remote controlled robots, they could explore the Martian surface and prepare the way for future missions. And on the off chance that we discover alien life on Mars (current life, I mean, not fossils), then our astronauts on Phobos could study that life from afar without risking any sort of biological contamination.
Personally, I’m not 100% sold on this idea. I kind of feel like if we’re going to go to Mars, let’s just go to Mars. But Buzz Aldrin is Buzz Aldrin, and I’m just some guy with a blog. The thing about the fuel costs for landing on Phobos vs. landing on Mars makes sense to me. And if it does turn out that there’s life on Mars, contaminating the Martian ecosystem with our Earth germs (or having Mars germs contaminate us) does become a serious concern.
But otherwise, do we really need a way station on Phobos? Is that a necessary prerequisite to landing humans on Mars? I don’t know. Maybe it would be helpful. When the time comes, maybe we really will go to Phobos first and land on Mars later. It’s possible.
Want to Learn More?
Once again, I’m going to recommend Mission to Mars: My Vision for Space Exploration by Buzz Aldrin. Lots and lots of ideas in that book about how we might one day travel to Mars and what we might do once we get there.