Space: 1999 has been on DVD for some time now.
http://search.deepdiscountdvd.com/search?p=Q&ts=custom&w=space+1999&search.x=0&search.y=0Borrowed a copy recently and didn't like it nearly as much as I did when I was a kid. But I still love its predecessor and once-meant-to-be prequel, "UFO."
I remember really not liking "Ark II" as a kid, though I don't remember many details, other than there being a kid named "Loki" and I always wondered why he didn't look like Thor's brother.

As I began typing this post, I was sure the vehicle was left over from a film called "Damnation Alley," but thanks to the wonder of the Wikipedia I see that is not true. The same entry reveals the Ark was built on a dump truck chassis. (
http://en.wikipedia.org/wiki/Ark_II )
Check out this site for pictures and clips. And other neat tidbits for kids of the 70s, like me:
http://www.70slivekidvid.comAnd if you really hated Roddenberry's "Earth 2" that much, you may enjoy this legendary clip where John Saxon gets his face knocked clean off his head by Lee Majors:
http://youtube.com/watch?v=OKSL5oTxee0Hands down my favorite clip on the web.