Thursday, August 27, 2009
Anyone following the debate over the past 15 years or so on which locations in the inner Solar System humans should be sent to could be forgiven for ending up with the impression that the inner Solar System is comprised of the Moon, Mars, and...and a bunch of other places that don't matter. The debate almost always seems to be Moon and Mars, Moon and Mars. The narrowing of the debate to these two locations though simply isn't based in reality. Here are a few examples.
Take the cloudtops of Venus as an example. 50 km or so above the surface of the planet you find yourself in an area more like Earth than any other part of the Solar System - temperature and atmospheric pressure are just about the same as they are at sea level here. The air is not breathable, however, the clouds are fairly acidic, and wind speed is extremely high, but none of these factors make a manned mission there impossible. In fact, since the atmosphere on Venus is denser than that on Earth, it also means that simply taking enough breathable air along with you will cause your habitat to float. You can see a detailed description of how this would work here. Also here.
Try bringing this subject up on a forum though and you will end up with a thread full of irrelevant arguments against the idea (I know, I've done it a number of times myself).
But the surface is so hot! - But it's not a mission to the surface.
But what if it leaks air and crashes to the ground? - What if your habitat leaks air in any other location in the Solar System? Is there anything particularly deadly about a mission to Venus compared to any other place where a single problem could result in the instant death of the entire crew? Didn't think so.
But who would want to spend all their time in the clouds above a dead planet? - I would. So would many others. The idea of being that close to Earth's sister planet is a phenomenal one.
Add to that the more frequent launch windows and less travel time than to Mars, and the idea of exploring Venus in this way (first we should send robotic flyers to check out the area of course) is just as worthwhile as a mission to Mars. But for some reason this is dismissed as a crackpot idea.
Next subject: sending humans to Ceres instead of Mars. I've written in detail about this here. In short, Ceres has more frequent launch windows, much less gravity (=easier to come back), no sandstorms or seasonal variation to worry about, and apparently has more fresh water in the form of water ice than all that on Earth. So why hasn't Ceres been given more consideration? Ah, that's right, because it hasn't been thought of as being a true planet. There really isn't any other reason than this one. If Ceres had been thought of as a true planet alongside all the others then we would have learned about it at school (mvemjsunp would be mvemcjsunp), and a few billion more people would have known about it. But in spite of its having hydrostatic equilibrium (=a spherical shape) and the same surface area as Alaska plus Texas plus California (or the same area as Kazakhstan or Argentina), it simple hasn't been thought of as a serious destination, truly for no reason at all. Here's hoping that Dawn will change that when it arrives in 2015 and we get to see Ceres close up for the first time.
One other issue based on nothing is thankfully beginning to receive some attention - the idea of a manned mission to a near-Earth asteroid, which I've written about quite a bit here. For a good forum post on the subject see here. A manned mission to a near-Earth asteroid really is a no-brainer, considering that it needs no landing (just a kind of docking) nor any special equipment to make the return trip, and also due to the fact that asteroids could possibly wipe out entire cities so it's probably a good idea to know as much about them as possible. Luckily the recent discussion on the lack of funding for a successful return to the Moon has turned up a silver lining in giving the idea of a manned mission to an asteroid more attention than before. To really get this idea out to the public it would probably be best to make a short film on the idea so that it can be more easily visualized - something that shows 1) just how close these asteroids can be, showing their distance compared to that of the Moon and Mars; 2) what it would look like for a spacecraft to approach, land, and for astronauts to walk on the surface; 3) why it's important for us as a planet to know as much about asteroids as possible.
I do remember a video on the subject being made before but the CGI was a bit sketchy and it didn't draw any comparisons between a mission to an asteroid and one to the Moon or Mars, which is necessary in order to show that the debate need not be between those two bodies alone.