necessary changes and move on. >> reporter: nasa celebrated the 29th anniversary of the shuttle launch. >> it's time to look back and reflect about all the great things that the space shuttle has brought us over the last 29 years. and so i think we're going, we're going places, we're going, we're doing a lot of interesting stuff up here. >> reporter: but the future of deep space exploration is changing. president obama is charting a new course for nasa. >> i am 100% committed to the mission of nasa and its future. >> reporter: back in washington, justice john paul stevens announced his retirement from the high court. the daily show's jon stewart poked fun at stevens, the oldest member of the court. >> justice john paul stevens began his career as a revolutionary war naval captain. then moved on to pursue his passion, playing bass for led zepell zepellin. following a string of hits, john paul stevens then became the pope, where his love of robes