Two astronauts who were teaching math and science to middle school students just 5 years ago went on a spacewalk together today, their path cleared of dangerous orbiting junk that had threatened the space station and shuttle. It's the first time two former schoolteachers have been on a spacewalk together, and is the third and final spacewalk for shuttle Discovery's mission.
Astronauts Joseph Acaba and Richard Arnold II had no luck trying to free up a jammed equipment storage shelf at the international space station, one of their main tasks. Using a hammer, they managed to loosen a pin that Acaba and another astronaut accidentally inserted upside down on the platform during Saturday's spacewalk. But the shelf mechanism would not extend into the proper position, despite repeated efforts.