Hello. I couldn't any trace of music form Uchuu Kyoudai, so I have found a link where to get the soundtrack from the anime: http://www.freedownloadanimemusic.com/uchuu-kyoudai-original-soundtrack-cd1-uchuu-kyoudai-no-theme/. It contains CD 1, CD 2 (which can be accessed by the link at the bottom of CD 1's playlist), and CD 3 (same applies with CD 2). Here's the soundtrack information if you're curious: http://vgmdb.net/album/41696. Whoever is interested in Uchuu Kyoudai (whether by watching it or hearing about it), you can finally enjoy the music! :)

Thanks.