By Alex Tresniowski and Champ Clark
Updated January 31, 2011 12:00 PM

He’s used to sitting in space shuttle cockpits, commanding a million switches high above Earth. But now astronaut Mark Kelly sits in a room at Tucson’s University Medical Center, where the only machines that matter are those monitoring his wife, Congresswoman Gabrielle Giffords. “He’s never far from her side,” says a friend, Arizona state representative Matt Heinz, of Kelly, who’s been with Giffords every day since she was shot in the head on Jan. 8. “He’s hearing about the investigation and the medical briefings; he’s at the center of that. And he has medical power of attorney, so that stops with him. He is calling all the shots.”

As Giffords continues what doctors call a miraculous recovery, part of that miracle, say those close to her, has to do with the love and steady support of her husband. Nearly two weeks after the Tucson shooting, Giffords, 40, is still surprising medical staff by gaining more and more movement in her arms and legs and even giving Kelly an unexpected neck massage; her condition has been upgraded from critical to serious. It’s not yet clear how full her recovery will be, but several close friends who spoke with PEOPLE are hopeful Giffords could soon be released to a rehab center, where she will keep drawing strength from the man they call her best friend. “Doctors are usually dismissive of the importance of things like friendship, but even her doctor was impressed,” says Florida congresswoman Debbie Wasserman Schultz, who was in the hospital room on Jan. 12 when Giffords opened her eyes and tried, with her first movements, to hug her husband. “She grabbed Mark around the neck, touched his arm and touched his wedding ring. Mark’s not an excitable person. He’s steady as a rock. But he was overcome with emotion.”

Still, Giffords’ injuries, like the tragic shooting itself, will take a long time to get over. A bullet hit Giffords just above her left eye and passed through the left side of her brain before exiting through the back of her skull. Doctors waited until the threat of dangerous brain swelling had passed before performing surgery on her damaged eye socket. In a two-hour operation on Jan. 15, doctors removed the rim of the socket and took out stray bone fragments, then rebuilt it with metal mesh. The surgeon, Dr. Michael Lemole, said the operation was successful-and that Giffords’ movements, including the neck rub she gave Kelly, may indicate a high level of function. “She’s recognizing him and interacting, perhaps in an old familiar way,” said Lemole.

Even so, both her doctors and Kelly are guarded in their optimism. “Gabby’s got a long road ahead of her,” Kelly told ABC’s 20/20. “But, you know, she’s a really, really tough woman.” Kelly, 46, is due to take off on his fourth shuttle mission-during which he’ll meet up with his twin brother, Scott, in the International Space Station-in late February. But it’s clear he has put his wife’s health ahead of the mission. “He told me, ‘I have a decision to make about this, but Gabby has to be a part of that decision,’ ” says Washington congressman and friend Adam Smith. “He said, ‘I’m going to wait until she is better and we’ll talk about it.'”

That deep regard for each other is typical of the couple’s loving but unconventional marriage. They met in 2003 when both were asked to attend a cultural exchange trip to China. At the time Kelly was married and Giffords was dating someone else. A year later, after Kelly was divorced, they got together. “Gabby had dated a lot and we didn’t like any of the guys,” says her former roommate Ken Cheuvront. “Some of them were creeps. But what she was looking for was a man’s man.” A tomboy who rides motorcycles, Giffords loved two things about Kelly: that he was a great father to his young daughters Claudia and Claire and that his office was a spaceship. “Gabby loves to do exciting things,” says Cathy Nichols, a friend since high school. “So when she met Mark, it was, ‘What’s cooler than an astronaut?'”

Their first date was in a maximum-security prison (Giffords was working on capital punishment legislation). Kelly, the New Jersey-born son of two police officers, “just jumped into the [electric] chair,” Giffords told the Arizona Daily Star. “The warden said, ‘All the boys want to do that.’ ” They wed in front of more than 300 guests at the Agua Linda farm in Amado, Ariz., with Kelly, a Navy aviator, in full uniform and Giffords in a secondhand Vera Wang gown. (The ceremony was green.) The inscription on Giffords’ gold wedding band: “You’re the closest to heaven that I’ve ever been.”

They had to skip a honeymoon, though, because of a space shuttle mission, setting the theme of their relationship. Kelly is based in Houston, and Giffords splits time between Tucson and Washington, D.C.; they do their best to get together at events and sometimes in Giffords’ Tucson home, but friends say they rarely spend more than two weeks together at a time. “They’re flying around the country doing their thing, but they find ways to meet up,” says Giffords’ good friend Raoul Erickson. “Maybe that’s why they are perfect for each other, because they have the same kind of lifestyle.”

Indeed, the absences between their tightly scheduled rendezvous help them stay “in a perpetual state of being newlyweds,” says Rep. Wasserman Schultz. “They get so little time together, and that time is precious.” When Kelly is away, “Gabby is like a lovesick teenager when she talks about him,” says her friend, former congresswoman Stephanie Herseth Sandlin. “They are just kindred spirits.” But on top of their similarities, they also complement each other. Giffords, outgoing and in the public eye, is grounded by Kelly’s quiet strength. “She loves to plunge herself into a crowd,” says Rep. Wasserman Schultz, “and Mark is just so proud of her and happy to let her shine.” And when they’re together, “he’ll sit with his arm around her or hold her hand; she will tease him and then giggle about it,” says Wasserman Schultz. “It’s just really cool.”

More than anything, say friends, the two are supportive of each other’s dreams. Kelly encouraged Giffords to run for Congress in 2006; Giffords is on hand for his space-shuttle liftoffs. Right after a recent launch, “I asked Gabby, ‘What did Mark say to you when he left?’ ” remembers her friend Carol West. “She said he told her, ‘Don’t forget to take out the garbage.’ I thought that was just so typical.”

Now, Kelly’s mission is to make sure his wife comes back to him. “Mark has a laserlike focus on getting Gabby better,” says Congressman Smith. “He hasn’t slept a hell of a lot these past days. He’s talking with her all the time and staying very positive.” The medical aspects of her recovery may be out of his hands, but the special, intangible benefits of their commitment to each other, say friends, cannot be discounted. “Gabby depends on Mark a lot, especially right now,” says West. “Seeing him constantly at her side at the hospital, that’s just what I’d expect him to do. He is very devoted to her, and she is to him. It’s just a wonderful love story.”