But the gas gun concept was actually realized and used on Gemini flights: https://en.wikipedia.org/wiki/Hand-held_maneuvering_unit https://en.wikipedia.org/wiki

But the gas gun concept was actually realized and used on Gemini flights: https://en.wikipedia.org/wiki/Hand-held_maneuvering_unit https://en.wikipedia.org/wiki/Hand-held_maneuvering_unit