A astronaut embarks on a solo mission to Jupiter when things go wrong and he becomes stranded in space headed towards the sun with no communication or control over the ship.

Potential for sure. I could see him saving himself by crashing landing on Mercury. Some place to die though hey? Ironically, he finds the first signs of alien life on Mercury but has no way to communicate that back to earth! doh! good luck with the project! cheers

I forgot to mention that it is a short film.

Not bad! Seems like you could have a large-ish climax if the ship drifts past Earth and then they fail to rescue him then!

It is good but for a short movie (very short) i think... . You should see "Moon" with Sam Rockwell. Very similiar to your idea.