Complex sentence: That same night, Jinx secretly enters NASA's computer room and prepares a "thermal curtain failure" operation on the Space Shuttle Atlantis while the group are on board, causing one of the boosters to ignite during the engine test.
Split into simpler sentences: That same night, Jinx secretly enters NASA's computer room and prepares a "thermal curtain failure" on the Space Shuttle Atlantis while the group are on board. This causes one of the boosters to ignite during the engine test.