Astronauts Test Their Jet Packs

Two spacewalking astronauts wrapped up construction work outside the international space station, then fired up their jet packs and cruised around. Jeff Wisoff and Michael Lopez-Alegria took turns jetting over and around space shuttle Discovery’s payload bay to test the small nitrogen-powered rocket backpack that could someday save an astronaut’s life. They were on a leash the whole time. But it was a loose leash. NASA insisted the spacewalkers be tethered for the jet pack demonstration. Because Discovery is docked to the space station, the shuttle could not immediately dash after the astronauts if their jet packs failed. “Oh man, this is so . . . unbelievable,” Lopez-Alegria called out as he concluded his test flight high above the Florida Keys.