Monday, March 29, 2010
Here's a brand new video from Ted.com (still no subtitles in any language, including English) featuring a talk by planetary scientist Joel Levine making the case that we should send an airplane to Mars, one that he and his team have already designed and are simply waiting for funding for. The title of the video is "Why we need to go back to Mars" and from that I was afraid that he would go from "Mars is geologically interesting" to "so let's send humans to Mars instead of the Moon" (ignoring the six-nine month journey time, radiation, difficulty of landing, etc. etc. etc.) but he only makes the case for an airplane to fly low over the surface of the planet and I'm in complete agreement with that. I wrote a post last year on why we need to explore the Moon first before Mars, but this is manned exploration only and Mars remains an excellent destination for robotic exploration.
A mission of this type might also lead to a discussion on sending a flyer to another planet, namely Venus. The technology involved would be quite different, but it would still be useful in showing that airplanes are another type of craft we can send to planets with atmospheres besides just probes in orbit and rovers on the ground.
The differences by the way are:
- An airplane to Mars would be an extremely short and fast mission, since the atmosphere is thin, solar energy is scarce, and Mars has day and night cycles like our own. An airplane on Mars would use its own fuel to zip over the surface, taking in as much data as possible while its fuel lasts.
- An airplane on Venus would be a solar flyer, a craft that stays about 50 - 70 km or so above the atmosphere instead of just 1-2 km for the Mars craft, and due to the extremely slow rotation of the planet it would be able to stay in the air indefinitely, or at least as long as the craft survives. Properly insulate it against corrosion and there should be no reason why it wouldn't be able to stay in the air for years.
- An airplane to Mars would be much more nail-biting as well. Being farther away (less help from mission control), closer to the ground and flying at a much higher velocity means it would have to be done perfectly. A solar flyer on Venus could conceivably miss its target by 20 or 30 kilometres (dropping down to 40 km above the surface for example) and still recover.
If NASA decides to fund a mission like this, two airplanes would probably be better than one. Creating two identical craft not only improves return, but also lowers costs and provides insurance in case one of them happens to fail.