I do not know if was ever on Mystery Science Theatre but it should have. The really bad space movie was The Green Slime.
Rated the worst movie of all time is Plan 9 from Outer Space which originally has Bela Lugosi in it but he died halfway through production so they took another guy and had him cover up his face from the nose down in all the scenes in which he (if you can call it that) acted.
I’ll never forget watching Green Slime with my “girlfriend” when I was like 10. I still remember the last part of the song nearly 50 years later! GREEN SLIIIIIMMMEE!!! lol