Space shuttle Endeavour's commander, Mark Kelly, has spent his entire military career considering the options, weighing the risks, making a decision, then forging ahead.
As Kelly embarks this week on his fourth space shot _ a dangerous undertaking, he admits _ the stakes are higher than usual. His congresswoman wife, Gabrielle Giffords, is still recuperating from an assassination attempt. He is needed at home.
Kelly and his five crewmates flew into Kennedy Space Center on Tuesday just before the launch countdown. He said that to his delight, his wife will be along "pretty soon," in plenty of time for Friday afternoon's liftoff.
"She's excited about making this trip," he said.
It will almost certainly be Kelly's last trip into space. This is NASA's next-to-last shuttle mission; the grand finale is set for this summer. Besides, his wife needs him more than ever, as do his two teenage daughters. All three will be at the launch, as will President Barack Obama and his wife and daughters.
Those who know Kelly well _ including identical twin Scott, also an astronaut _ understand and support his decision to blast off on the 14-to-16-day flight to the International Space Station.
Both 47-year-old Kellys honed their flying skills as high-performance Navy pilots. Compartmentalizing _ putting their personal lives aside for the job _ comes naturally. So does honoring a commitment.
"I've given this mission everything I would have if the events of January did not happen," Kelly said at a news conference last month. "I'm very focused."
On Jan. 8, Giffords was meeting with her Arizona constituents outside a supermarket in Tucson when she was shot in the head, one of 13 people wounded. Six were killed, including a 9-year-old girl and a federal judge.
"We want Mark on the mission. We always have," said astronaut Andrew Feustel. "He's been our commander for a year and a half, and that's the way the mission needs to fly."
What happened to Giffords, while heartbreaking, "doesn't influence us on the mission at all," Feustel said. "It's really not had any significance on the technical aspects of the mission."
When reminded that even astronauts are human, Feustel laughed. "Are we?" he asked.
Kelly, an astronaut for 15 years, loves speed and accepts risk. He always has. With police officers for parents, the brothers grew up in West Orange, N.J., knowing more about danger than most children.
Curiously, Kelly got his start on slow ships. While studying at the U.S. Merchant Marine Academy in the mid-1980s, he found himself on a grain carrier in the Pacific, chugging along at 12 knots from Seattle to Egypt. It took more than a month just to get to Singapore.
"I thought, `Boy, this is way too slow,'" he recalled. "That's when I started thinking about flying airplanes in the Navy."
Kelly wasted no time going to flight school. Both brothers ended up in the same class at the Naval Test Pilot School in 1993.
Soon, fighter planes weren't fast enough for either of them. In 1996, they were selected as NASA astronauts.
Kelly already has been through three launches. So has his brother. They're the world's first and only space siblings.
Their father, a retired policeman, was "pretty nervous and a little freaked-out" during the most recent Kelly launch _ Scott's flight aboard a Soyuz rocket from Kazakhstan in October.
Each brother is at the other's launch no matter what, supporting their parents as well as the other's wife and children.
This will be the fourth time Giffords, 40, has traveled to Kennedy Space Center for a launch. She attended her husband's liftoffs in 2006 and 2008 and her brother-in-law's in 2007. She was too busy campaigning last fall to make it to Kazakhstan.
Endeavour was supposed to fly in February, but late last year the launch was pushed into April because of delays with the preceding mission. That nixed any possibility of the Kellys crossing paths aboard the space station. Then Giffords was shot; had the flight remained on track for February, Kelly would have pulled out.
Scott, who served as space station commander, returned to Earth in March.
For Mark Kelly, the prospect of flying in space with his brother and best friend was enticing while it lasted. Who else might Kelly want to fly with in space?
"If it wasn't so dangerous, maybe my kids and my wife and my brother all at once," Kelly said. "But this flying in space stuff is a risky proposition. So I wouldn't let my kids do it, not at their current age."
After his wife was wounded, he took a monthlong leave from mission training, camping out at her hospital bedside in Tucson for two weeks until she was transferred to a rehab center in Houston, his home base. Her progress was so swift _ and her rehabilitation schedule so intensive _ that he resumed training in February at Johnson Space Center. That is what his wife would want, he explained.
Kelly, who is of Irish-Catholic descent, has publicly acknowledged his belief in the power of prayer in Giffords' remarkable recovery. She is Jewish; a rabbi married them in 2007.
"I hadn't been a big believer in faith until recently," Kelly said at the National Prayer Breakfast in Washington less than a month after the shooting. "I thought the world just spins and the clock just ticks and things happen for no particular reason."
Kelly was moved by all the angels, Bibles and prayers that appeared on the lawn outside his wife's hospital. One windless morning, as hundreds of candles burned at the makeshift memorial, he said he realized it was as sacred a spot as any church, temple or mosque: "A place with heaven itself as a ceiling."
From space, "you have an entirely different perspective of life on our planet," he said. "It's humbling to see the Earth as God created it in the context of God's vast universe."