Simplified Aid for EVA Rescue

Simplified Aid for EVA Rescue (SAFER) is a small, self-contained, propulsive backpack system (jet pack) worn during spacewalks, to be used in case of emergency only. If an astronaut would drift off, it provides free-flying mobility to return to the spaceship. It is worn on spacewalks outside the International Space Station (ISS), and was worn on spacewalks outside the Space Shuttle. So far, there has not been an emergency in which it was needed. SAFER is a small, simplified version of the Manned Maneuvering Unit (MMU), which was used for regular maneuvering.