The film is set during
a fictitious Shuttle Explorer's STS-157 mission. Dr. Ryan Stone (Sandra Bullock) is a medical engineer
on her first space shuttle mission aboard the Space Shuttle Explorer. She is
accompanied by veteran astronaut Matt Kowalski (George Clooney), who is commanding his final expedition. During a
spacewalk to service the Hubble Space Telescope, Mission Control in Houston
warns the team about a Russian missile strike on a defunct satellite, which has
caused a chain reaction forming a cloud of space debris. Mission Control orders
that the mission be aborted. Shortly after, communications with Mission Control
are lost, though the astronauts continue to transmit, hoping that the ground
crew can still hear them.
