Personally, I would recommend looping it in Audacity first. I would repeat the sound enough times to last several minutes.
I tried to loop the sound, but I couldn't do it in a way that sounded good. It still looped though
I have altered your world slightly so a sound plays as your ship moves. If you think it sounds a bit weird, its because I decided to just mangle the sound and put it into a loop.
The sound you gave me had a very brief pauses at the beginning and end. You would need to cut those (and likely a little of the sound) for the loop to sound more seamless.
I'm uploading the modified world into my mediafire account. One moment...
Edit:
Here it is! I hope this helps!
==============Some of my Games and Ideas===========
Sky Warrior: http://www.alice.org/community/showthread.php?t=6291
Health Bars: http://www.alice.org/community/showthread.php?p=36968#post36968
Sky Warrior: Dual Force: http://www.alice.org/community/showthread.php?t=7174
Want to make your own space game? http://www.alice.org/community/showthread.php?t=6389