Thursday, September 27, 2007
Top of the world
More random thoughts as I drag my feet before slogging through my pan of Don Juan Giovanni. A most excellent site is Astronomy Picture of the Day - I recommend checking it out every morning for a quick blast of just how marvelous the universe truly is. The photo above was from Sept. 16. The explanation is as follows:
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 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.