Earth is doomed!

Spoiler alert!
The scientist was grossly negligent, and the others watching him be grossly negligent seemed to have no common sense.
The alien could only be resuscitated with oxygen and heat, but could withstand the vacuum and sub-freezing temps of space with no problem.
The sequence of events leading up to the surprise capsule twist at the end did not cohere. It just seemed like a sad ending for the sake of a sad ending.