I'm sorry but this is just way, way too long for what it provides. Don't get me wrong your animation looked good (the whole launch sequence was nicely done), but that was 9 1/2 minutes of what could have been done just as effectively in about 2. I was ready to turn it off before the second stage dropped (5 minutes in). With no speech, character development or plot other than 'we are going to Mars', so we don't care that they get sucked into a worm/black hole, this whole film fells empty to me and lacks depth. And the one development in the plot doesn't lead to any conclusion or wrap up, it is just over (no payoff). On those lines with how nice the first bit looked (indeed up until the encounter with the black hole), the black hole encounter looked cheesy and hastily made sadly doing no justice to the earlier portion of the film. When you consider that the viewer had watched 90% of the film before the encounter and (despite being well made) nothing had yet happened when the encounter happened it really should be something. Something that justified the curiosity and desire that pushed the viewer to hang on through the rest of the film.
Now, I do understand that this was made for a contest with a deadline, but even you said in your comments that you didn't get to finish it the way you would like. Right? You totally should finish it the way that makes you happy. This is mostly beautiful, but empty. I think that giving this 2.5 stars is being generous, because I wouldn't recommend anyone watch a flash toon that is almost 10 minutes long with no real payoff.
Keep on, you definitely have talent.