Man-Maneuvering Units

Man-Maneuvering Units (MMUs), also known as astronaut-maneuvering-units (AMUs) or colloquially as space jetpacks, are nitrogen-propelled devices used by astronauts to maneuver in the vacuum of space during Extravehicular Activity (EVA).

Technical Overview & Evolution

  • Functionality: Uses compressed nitrogen gas expelled through nozzles to provide thrust for translation and rotation in microgravity.
  • Design: Typically backpack-mounted, allowing hands-free operation. Critical for safety and retrieval operations.
  • Historical Context:
    • Evolution from earlier simpler restraint systems to fully autonomous maneuvering capabilities.
    • Designed to address the critical risk of an astronaut drifting away from the space-station or Space Shuttle.
  • Operational Challenges:
    • Finite propellant supply limits operational time and correction capability.
    • Risk of disorientation or inability to stop rotation/translation if malfunctions occur.
    • Physical strain on the astronaut due to pressure and movement constraints.