Write a compelling sci-fi story set in a future where Earth is slowly dying, about a group of astronauts who embark on a dangerous space mission in order to save their planet from utter destruction. Your story should be character-driven, explore themes such as sacrifice and redemption, and feature imaginative and scientifically plausible descriptions of space travel and alien life. Make sure to build tension and suspense, leave room for twists and surprises, and ultimately deliver a satisfying conclusion that leaves the reader with a sense of hope for the future of humanity.
This prompt doesn't seem malicious.