"We have put a plan together [so] we can get there as quickly as we can," said Tony Ceccacci, the lead flight director for the Hubble mission. "We have between 17 and 25 days that the 125 vehicle can stay on orbit, and we have very high confidence we can get a rescue vehicle to them in that time."
Getting Endeavour to Atlantis would only be half the battle. Atlantis' crew members would need to be transported across the gap between the two shuttles.
Endeavour would rendezvous with Atlantis the day after launching from the Kennedy Space Center. The two space shuttles would then orbit payload bay to payload bay, at a 90-degree angle. Endeavour's robotic arm would grapple the orbital boom system on Atlantis, and then the spacewalkers from Endeavour would retrieve their colleagues from Atlantis in a series of three spacewalks — including two on one day, something NASA has never done before.
Four of the astronauts on the Hubble crew are trained spacewalkers.
Altman, pilot Greg Johnson and robotics officer Megan McArthur are all training on spacewalks for this what-if scenario. The training also includes an intense multi-day simulation at the Johnson Space Center with Mission Control and all the flight support teams.
Astronaut John Grunsfeld is one of the four spacewalkers who will fly on Atlantis. This mission will be his fifth trip into space and his third trip to repair the Hubble. Grunsfeld is also an astronomer, who says keeping the Hubble telescope flying is a mission worth the risk.
"When you think about risk, it is all relative to what is the reward, and I think in the big picture Hubble is something that I certainly feel is worth risking my life for because it is about something that is so much bigger than all of us," Grunsfeld said. "It is about science, it is about inspiration, it is about discovery. It is about all the kids who will look at the Hubble images and dream."