KENNEDY SPACE CENTER , Florida ( CNN ) -- With space shuttle Atlantis on its way to upgrade the Hubble Space Telescope , that leaves one shuttle , Endeavour , at the ready on the other launch pad here . Space shuttle Endeavour , in background , sits poised to launch in case Atlantis , in foreground , meets trouble . And that 's where everybody at NASA wants it to stay . `` We have high confidence that we 're just having that thing over on pad B to make it look nice , '' said mission flight director Tony Ceccaci . Endeavour is far more than a postcard picture -- it 's on standby in case something goes seriously wrong with the Atlantis mission . For example , NASA has estimated there 's a 1-in-221 chance the shuttle could be struck and crippled by orbiting space debris . If such an incident were to thrust the seven Atlantis astronauts into danger , Endeavour would blast off within days in a last-ditch attempt to save them . Endeavour Cmdr . Christopher Ferguson believes his crew is up to the task . `` I feel as confident about our ability to pull this off , if need be , as I would any other mission , '' he said . The idea of a standby rescue spacecraft grew out of the 2003 Columbia disaster , in which that shuttle disintegrated over Texas during re-entry into the Earth 's atmosphere . But until now , there 's been no need . All the previous missions since Columbia have gone to the International Space Station . The crew of a damaged shuttle could take refuge there for months if need be until another shuttle was readied to retrieve them . But Atlantis is going to Hubble , whose orbit is n't anywhere near the space station . If their spacecraft malfunctioned , the seven-member Atlantis crew would have to survive aboard -- probably for days -- until they could be rescued . `` In this case it 's a much shorter fuse , '' Ferguson said . `` Consumables like food and oxygen would run out quickly . So the reason we 've gotten this crew trained and spooled up and ready to go on literally a moment 's notice is because they [ Atlantis 's crew ] have no place comfortable to go stay for a long period of time . '' But the rescue would be no cakewalk . Endeavour would need to pull up underneath Atlantis and hook on to the other shuttle using its robotic arm . Over the course of two days , the seven Atlantis astronauts would spacewalk over to Endeavour by holding on to a tether line strung between the two spaceships . Atlantis mission specialist John Grunsfeld would go first -- and , actually , twice . Grunsfeld would spacewalk to Endeavour , grab an extra EMU ( extravehicular mobility unit ) spacesuit and take it back to Atlantis . He would then return to Endeavour with one of the Atlantis astronauts not trained in spacewalking . With the Atlantis crew safely aboard , Endeavour would pull away and begin preparing to head home . Atlantis Cmdr . Scott Altman said that knowing Ferguson and the other three members of the Endeavour crew are ready in case of an emergency gives him peace of mind . `` Even in the worst-possible imaginable case , we can stay up there and last until somebody comes up and gets us , '' Altman said . `` So it feels like we have all our bases covered . '' So what would happen to Atlantis ? Ferguson said mission leaders would prepare the crippled shuttle for what they call a `` disposal burn '' -- a safe , remotely controlled landing of Atlantis . `` If it comes to it , we certainly do n't want a space shuttle coming in over a populated area , '' he said . `` So we want to control the burn so it does end up in the ocean . '' In all , eleven astronauts would be stuffed into Endeavour . A space shuttle has never carried that many . The four Endeavour crew members would hang out in the flight deck , while the seven Atlantis astronauts would squeeze into the mid-deck area . The journey back to Earth would be uncomfortable . But Ceccaci , the flight director , says that would n't matter as long as everyone was safe . `` Wrap me in bubble wrap and get me home safely , I would n't care , '' he said . `` I would n't care how cramped it is . ''
The shuttle Endeavour and its crew are standing by in case of a emergency in space . Endeavour would blast off to rescue the crew of shuttle Atlantis . Atlantis blasted off Monday to upgrade the Hubble Space Telescope . A rescue mission would involve two tricky days of spacewalks between shuttles .