I read this book in the early 2000's in school. I only recall the plot vaguely. I do remember some people having crash landed on an alien planet. I believe it was a deadish place, no one around (perhaps post apocalypse). I recall it being flooded, maybe a swamp. When I think about it, it could have been a future Earth they landed on... my memory of it isn't great. They are trying to escape the place, but must repair the ship. Some of the people get into the the ship anyway later on and leave the others behind and the ships reactor melts/overheats or something during liftoff.
Not much to go on, I know, but someone might recognize the plot.