NASA says the three remaining space shuttles -- Atlantis, Endeavour and Discovery -- will remain grounded until next year. Once shuttle launches resume, a second orbiter will be on standby to rescue the astronauts if their spacecraft is damaged in flight.
NASA had been aiming for its first post-Columbia launch as early as this fall, but officials decided to move the flight back to no earlier than March of next year.
Because of the Columbia disaster one year ago, NASA has decided that all shuttles from now on will be devoted to completing the international space station. That way, the astronauts can inspect
and repair their ships at the orbiting outpost and await rescue there if the damage is too grave.
Rescue shuttles may not fly immediately, either. The international space station could support seven extra astronauts for as long as 45 to 90 days before food, oxygen and other supplies start to run out.