The astronaut husband of wounded Rep. Gabrielle Giffords will announce Friday that he will fly on space shuttle Endeavour's final voyage, according to a report.
Politico said that a source familiar with the decision had confirmed Mark Kelly has decided to go ahead with the historic mission.
NASA said late Thursday that Kelly would hold a press conference Friday afternoon at Johnson Space Center in Houston.
The astronaut who has been substituting for Kelly during training, however, was not listed among the three participants, which prompted speculation that Kelly has decided to fly in April.
His identical twin, Scott, currently commander of the International Space Station, also hinted in an interview this week that his brother would choose to fly.
Mark Kelly took a leave from training after Giffords was gunned down at a Tucson, Ariz., shopping center on Jan. 8. She's been undergoing rehab in Houston for the past two weeks.
Kelly spent the past month debating whether to step down as commander of Endeavour's two-week mission.
In making his decision, Kelly must weigh more than a two-week flight away from his wife, however. Preparation for the mission requires 60 hours a week of intensive training, and Kelly is already a month behind. If he stays at the apartment near the the hospital where Giffords is a patient, he'll also have to commute two hours a day to NASA. If Kelly returns to his home near NASA, he'll face a a three- to four-hour trip to and from the hospital for which he'll have little time during training.
Two previous astronauts — Jeff Ashby in 1997 and Robert Stevenson in 1984 — withdrew from flight assignments to be with dying wives. Ashby later flew several shuttle missions, but Stevenson was medically disqualified before a second chance appeared.
In the meantime, NASA named a backup commander, Rick Sturckow, who joined crew training.
Kelly, 46, has flown three times aboard space shuttles; April's space station delivery mission would be his fourth. Endeavour's liftoff with a crew of six is targeted for April 19.
The fact that Sturckow is not listed for the press conference was telling, indicating that Kelly will launch as scheduled, said Howard McCurdy, a public policy professor and space expert at American University in Washington, D.C.
And because it will be one of the last two launches and because of the drama behind the shooting of his wife, that shuttle launch will "get the same kind of attention that the (1998) John Glenn mission" received, McCurdy said.
NASA is retiring the shuttle fleet this year; three missions remain.
McCurdy suggested the public will embrace Kelly's decision, because it provides a sense of normalcy.
"We all want her to go back to Congress; we'd like them both to continue their careers and we'd like them to be whole and normal as if this thing had never happened," said McCurdy, author of the book "Space and the American Imagination."
Both Kellys are Navy captains and joined NASA's astronaut corps in 1996. In an interview from the space station Wednesday, Scott Kelly said their Navy background as high-performance pilots enables them to put their personal lives aside, when necessary, and focus on the job at hand.
"My brother certainly is very good at that," he told The Associated Press. "If he does choose, and NASA management chooses, for him to fly this mission ... I am absolutely 100 percent confident that he will have no problem fulfilling his responsibilities the same way as if this incident would have never occurred."