Bruce and the MMU
Yeah that was a heart stopper of a moment when he jetted from the Shuttles proximity, but even in Lost In Space of that era (1964) lifelines and tethers were SOP when major West left the Jupiter 2 for a EVA. Chalk it up to a error, I say and when I make my spacetrip ain't no way i'm going on EVA without a tether of some sort