September 16, 2007
Every candle on your cake is a tiny imitation of the stars that made you possible.
To Fly Free in Space
Birthday · September 16, 2007
A little universe, just for you
Your date.
Ready to give.
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APOD published September 16, 2007. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.
At about 100 meters from the cargo bay of the space shuttle Challenger, Bruce McCandless II was further out than anyone had ever been before. Guided by a Manned Maneuvering Unit (MMU), astronaut McCandless, pictured above, was floating free in space. McCandless and fellow NASA astronaut Robert Stewart were the first to experience such an "untethered space walk" during Space Shuttle mission 41-B in 1984. The MMU works by shooting jets of nitrogen and has since been used to help deploy and retrieve satellites. With a mass over 140 kilograms, an MMU is heavy on Earth, but, like everything, is weightless when drifting in orbit. The MMU was replaced with the SAFER backpack propulsion unit.