In Yoreh Deah (282) it seems that you can't simply take a sefer Torah out. There needs to be a holy, good purpose/reason for taking it out or for travelling. To take a sefer Torah to the moon when there is no place for it to reside and no Minyan in which it would be read, it seems unlikely that this would be permitted. Furthermore, the journey to the moon is not necessarily kavodik - how would it be transported etc. are all questions that would require halachic discussion and supervision. As a practical example it would be forbidden to sleep or lie next to the Sefer Torah. In space is this even possible not to do?
Sifrei Torah that remain untouched tend to wear out much faster than those read on a regular (weekly) basis. The reason is that the ink is constantly expanding and contracting as it is rolled, and thus bonds to the parchment more readily. Leaving a sefer Torah in an environment where the elements could actually damage it, would defeat any objective. Solar winds, low gravity, low atmosphere, low oxygen could have a deleterious affect on the parchment and ink. It could not, but one would have to test this in a real life example - perhaps a sofer would write some text on parchment, send it up to the moon for a year, and then get it back to see the effects. This would be an expensive undertaking for any mission.
There are also Hashkafic issues. Is there legitimate reason to send a Sefer Torah to the moon? If it is an act of preservation, the Jewish people have survived more than 2000 years of tumultuous history, Their sifrei Kodesh have survived as well, Hashem has provided the means for two miracles, there is no need to worry about that.
If these places are colonized, would there be any reason for a Jew to go? It would seem that it would be forbidden to go to Mars if there is no Minyan etc. If necessity required it, then the appropriate questions will be posed to the leading halachic authorities about the most appropriate action in such a scenario should be.