Wednesday, October 07, 2009
Another success for VASIMR happened in the last few days, complete with the eerie and Star Trek-ish videos we're used to. The last publicized test happened in July with an output of 32 kW, but this time a second stage was added to further energize the plasma until it reached over 200 kW. This number is important because 200 kW is what is needed for the proposed VF-200-1 engine which is to be tested in space to demonstrate how the technology works in practice.
The first use of the engine will be to raise the orbit of the ISS, but it will eventually be able to be used for missions to other planets, and the most anticipation comes from its ability to shorten the travel time from months to weeks for nearby planets. Mars currently takes about six months to reach, and with VASIMR it would only take about 40 days. Venus would then probably take under a month (!), and Ceres perhaps two months.
VASIMR is in my opinion the only way that Mars advocates will be able to make the case for a manned mission to Mars, because some of the largest issues regarding Mars have to do with the journey time - especially radiation, carrying enough supplies for a six-month journey, and the effect of the time spent in zero g. Each one of these problems would be drastically reduced with such a shortening of the travel time.
Nevertheless, 39 days still does nothing to increase the launch window frequency to the planet (about one launch window every 2.5 years), and landing is still an unsolved problem. Communication between Earth and Mars also still takes anywhere from a few minutes to almost an hour.
Also remember that exploring space is an international effort and many countries have now developed to the point where they are able to send their own probes to the Moon, while Mars is still beyond their grasp.
Ideally it would be best to begin colonizing the Moon as soon as possible, keep on working on technologies such as VASIMR, and eventually reach the point where we are able to build and send craft up from the surface of the Moon instead of Earth, since the escape velocity is a mere 2.38 km/s compared to 11.186 km/h on Earth. With that a probe to other parts of the Solar System could be sent using a rocket a fraction of the size of the ones currently used, just as long as it could be constructed on the surface of the Moon.
Now for the creepy and futuristic videos of the engine firing:
Then VASIMR at full power:
And a view of the scientists themselves as the test is conducted:
After having lived for a certain time on the Moon we should be able to tell just how much gravity humans need for long-term survival. My suspicion is that the 16% gravity on the Moon will be more than enough, due to the fact that it acts on the body 24 hours a day and that exercise using normal implements (weights, bars, etc.) will be possible, but if for some reason it turns out that humans just aren't built for any gravity but 1g then perhaps the only place we can truly colonize in the Solar System would be either the cloudtops of Venus, a rotating space station, or a space station on the surface of just about anywhere as long as we have a centrifuge to simulate normal gravity for enough hours per day. But since we've shown that we can live in 0g for as much as 437 days (Valeri Polyakov), I really doubt that 0.16g will turn out to be a problem.