Our Place in Space: Phobos

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…


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.

Sciency Words: Telerobotics

Today’s post is part of a special series here on Planet Pailly called Sciency Words. Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together. Today’s term is:


This is a pretty easy one, I think. Telerobotics refers to controlling robots from a distance, usually a great distance. This is in contrast to robots that function autonomously or machines that require direct human control.

The word comes from the familiar Greek root tele-, meaning “far away,” and of course the word robot, which originally comes from Czech and means something like “forced labor.”

A wide variety of fields use telerobotics, but for the purposes of this blog we’re most interested in its use in space exploration. At this point most if not all spacecraft are telerobotic in nature. They receive instructions from mission control on Earth, carry out their instructions, and then transmit their status back to Earth so that mission control can decide what to make the spacecraft or space vehicle do next.

The problem, of course, is that this back and forth communication is restricted by the speed of light. In the case of the Mars rovers, this means that even performing the simplest tasks can take hours and hours. It’s very frustrating, especially for the rovers.

This is one of the biggest reasons Buzz Aldrin and others say we should send astronauts to Phobos (one of Mars’s moons) before sending anyone to Mars itself. From a small Phobos base, astronauts could telerobotically control the rovers in real time. The speed-of-light delay would be negligible.

The rovers could cover a lot more ground that way, dramatically speeding up our exploration of Mars. Also, when the time comes, the rovers could be used to quickly prepare a landing site and assemble habitat structures in advance of the first human colonists arriving on Mars.

The Monolith of Phobos

On Tuesday, I landed on the surface of Phobos, the largest and innermost moon of Mars. Today, I’m doing a bit of sightseeing. Yes, there are sights to see on this rocky, little moon. Or at least, there is one sight worth seeing: the Monolith of Phobos.

I’m kind of surprised that I hadn’t heard about this before: a mysterious, boxy-looking object estimated to be about 90 meters wide jutting out of the surface of Phobos. Apparently it’s something Buzz Aldrin talks about a lot.

Aldrin mentioned it in an interview on C-SPAN, saying that this is the kind of mystery that could really get the public interested in a mission to Phobos. Aldrin also wrote about the monolith in greater detail in his book Mission to Mars: My Vision for Space Exploration (which is where I first heard about it).

So I’m going to go check this monolith out. I mean, it’s probably just a big rock. I bet it doesn’t even look so monolithic when you see it up close. It certainly was not put there by aliens (as many conspiracy theorists insist that it was) or that it’s anything like the monoliths from 2001: A Space Odyssey.

Except… what is that noise? It’s like some kind of eerie music….

Welcome to Phobos (Watch Your Step)

So I know I’m supposed to be blogging about my totally for real trip to Mars, but I actually haven’t landed on Mars yet. Actually, I’ve read a lot of expert opinions suggesting that any long term mission to Mars should really start with a mission to Phobos, Mars’s largest and innermost moon.

It’s an idea that Buzz Aldrin advocates for in his book about Mars, and it’s something that’s spelled out in a little more detail in this NASA technical report. Basically, the delta-v required to travel from the surface of Earth to Phobos is less than the total delta-v to travel from Earth all the way down to the surface of Mars.

That means less fuel, which means lower costs, and once we’re there Phobos can be used as a sort of vanguard outpost to help prepare for the full scale exploration and colonization of Mars.

Unfortunately for me, landing on Phobos and taking my first steps on this very, very tiny world—well, it didn’t go the way I expected it too.

Don’t worry. I made it back to the ground. Eventually.

You see Phobos is more like an asteroid than what we’d typically think of as a moon. If fact Phobos may actually be an asteroid that Mars kidnapped from the asteroid belt. Anyway, the point is Phobos is small. Very small. And so it does not have a whole lot of surface gravity. If I did my math correctly, we’re talking about less than 0.1% the surface gravity of Earth.

So in order to land on Phobos and stay on Phobos, I recommend bringing grappling hooks or some sort of tethering system, or maybe something like the harpoon gun the Rosetta Mission tried (unsuccessfully) to use to latch onto comet 67P.

As for walking around on Phobos’s surface, I’d say tread lightly. If you put too much force into your footsteps, you’ll have several long, long minutes to think about your mistake as you drift slowly back down to the ground.