Astronaut Mark Kelly: wife's recovery is No. 1 priority

NASA astronaut Mark Kelly said in an interview aired tonight that tending to his wife's recovery from a gunshot wound to the head was his top priority, but he hoped they could discuss together whether he should continue to lead Endeavour's final flight in April.

"That’s a tough question. I don’t know," Kelly told ABC's Diane Sawyer of whether he would remain commander of the 134th shuttle flight. "I've flown in space three times. I don’t have to do it again. My goal though is to make sure that my crew is safe and they can execute this mission safely."

Kelly on 20/20 made his first extended comments about the mass shooting Jan. 8 that injured his wife, U.S. Rep. Gabrielle Giffords, an Arizona Democrat whose condition doctors say is improving.

He said NASA protocol did not automatically require an astronaut to cede his position in a family crisis, that "it depends what it is." The agency has named a backup commander if Kelly bows out of the mission.

Asked about the possibility of sacrificing his dream to fly in space again, Kelly said "things don’t always turn out as you expect, they just don’t."

"My No. 1 priority is her. Ideally, I’ll have this discussion with her. I’ll consider what she says. Hopefully, we can make this decision jointly, but I get the final say on this one. Usually she gets a say."

Kelly said he would remain at Giffords' hospital bedside "as many (days) as it takes. Whatever it takes."