There are hints that astronaut Mark Kelly will blast into space in April, as commander of Endeavour's final voyage. That would mean leaving his wounded wife, Rep. Gabrielle Giffords, to continue her rehab without him for at least a few weeks.
She has limited movement on her right side, and no one has said if she can speak. She was shot in the head not quite a month ago in an attack by a gunman.
Kelly tweeted on Wednesday: "Today was a huge day for GG. Lots of progress!"
Kelly's decision to take a risky rocket ride so early in her recovery may seem startling. But those who know the couple, as well as doctors and rehabilitation experts, say it's a personal choice. And for this modern, high-powered couple, not an extreme one.
"I don't think he can lose either way," said Dr. Louann Brizendine, a psychiatrist at the University of California at San Francisco and author of "The Male Brain" and "The Female Brain."
If he decides to go, she said, people will understand that it's for a short period of time. "It's a one-time opportunity perhaps for him. It's what he's trained to do, and also he would only leave if he knew she was in super-good care," Brizendine said. "So I don't think he'll get terribly criticized if he goes."
On the other hand, if he stays, "he would get a lot of praise and a lot of kudos, for staying by her bedside," she said.
Research shows a strong social support network - family, friends, church or similar - is crucial for rehabilitating patients and improves the outcome.
But that doesn't mean a spouse has to be there 24-7, 365 days, said Dr. David Lacey, medical director of acute inpatient rehab services at Wake Forest University Baptist Medical Center in North Carolina.
"You also have to look at what's normal for the couple," Lacey said. "If it were my parents who had almost never been apart for the entire 50-some years they were married, all of a sudden changing that structure would be a pretty dramatic impact."
But what's normal for Kelly and Giffords, through their three-year marriage, is spending a few weeks apart at a time - he in Houston, she in Washington or her home state of Arizona. However, Kelly, 46, kept vigil at her side in the days immediately after the Jan. 8 shooting in Tucson. The rampage outside a supermarket left six dead and 13 injured.
By now, Giffords, 40, should be at a stage where there's little risk for complications, Lacey noted.
"He has to search deep how he feels about where he's going to be emotionally five, 10, 20 years from now because she's going to live through this now," Lacey said. "No matter what her outcome, whether it's very positive or not so positive, he's going to be in this for the long haul. What occurs during that two- to three-four week span of the training and the flight may be insignificant over the next 10 years. Either way."
The ultimate goal of rehabilitation, experts say, is for the patient and family to get back to a near-normal lifestyle.
The person who knows Kelly best - his identical twin brother Scott - said from orbit Wednesday that Mark is a logical, thoughtful guy who is weighing all the considerations. The two have discussed the options in depth, and Mark is leaning one way, his brother said. NASA management will need to sign off on it, if he decides to fly, said Scott, commander of the International Space Station.
A decision should come "fairly soon," he told The Associated Press. He declined to elaborate, but stressed the decision will be a good one.
His remarks hinted that his brother will decide to resume training for Endeavour's flight to the space station.
"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," Scott Kelly told the AP. He said their background as Navy pilots help them separate their personal and work lives.
It's relatively new territory for NASA.
In all the astronaut switch-outs over the years - not even a dozen - only one instance comes close to this.
In 1997, shuttle pilot Jeffrey Ashby walked away from what would have been his first space flight, just four months out. His wife Diana, suffering from melanoma, had taken a turn for the worse. She died two months after he pulled out of the mission.
Ashby empathizes with Mark Kelly's situation.
"Their decision is complex and personal," Ashby said in an e-mail. "I have no doubt that my friends Mark and Gabby will make the right decision for their family and for NASA."
Ashby went on to fly three times in space, before leaving NASA.
Mark Kelly already has rocketed into orbit three times. But the shuttle program ends this year, after just three more flights.
NASA aims to launch Endeavour on April 19, provided Discovery takes off later this month as planned.
To buy time, NASA recently named a backup commander, Rick Sturckow, for the two-week space station delivery mission. He joined crew training two weeks ago; the intensive sessions can last into the evening and fill weekends this close to flight.
Around the same time, Mark Kelly decided on Houston for his wife's rehab so he could be close to home and his job at Johnson Space Center. He is concentrating on his wife's care, but also has been back to work, his brother said.
This is Giffords' second week of rehab at TIRR Memorial Hermann hospital. In a Twitter update early Wednesday, Mark Kelly said Giffords is making "Lots of progress!"
TIRR Memorial Hermann's Lex Frieden, professor of biomedical informatics and rehabilitation at the University of Texas Health Science Center at Houston, said Kelly's decision about his NASA flight status won't be the only important one he needs to make during his wife's long rehabilitation.
Public opinion is irrelevant, Frieden said. "What's important is the decision that they make and the comfort they have with that decision ultimately."
Mark Kelly has said he'd like the decision to be made jointly, with his wife's opinion, if possible.
A former NASA colleague, Susan Still Kilrain, said if she can, Giffords will tell him to go.
Kilrain, in 1997, became the second American woman to pilot a space shuttle. Then, she was single. She recalls how Ashby's wife, Diana, urged him to continue with his mission training despite her cancer.
"She really wanted him to stop sitting around and waiting for her to die," Kilrain said. "All the wives would feel that way, and his wife (Giffords) seems to have a very big support system."
That said, there's no way Kilrain would resume training under the Kelly-Giffords circumstances. Women, she noted, tend to be the caregivers. She points to her own life story: She stood down from space flying after her first child was born, and quit NASA in 2002. She's a stay-at-home mom to four children, ages 4 to 11.
"Me personally? I wouldn't fly," Kilrain said from her home in Virginia. "But I certainly would definitely respect his decision to fly. I wouldn't second-guess that in a minute."
Melanoma Research Foundation: http://www.melanoma.org/community/diana-merriweather-ashby