Mark Kelly was elected to Congress 10 years after Gabrielle Giffords survived an assassination attempt. Here's a timeline of their relationship.

When they met, Giffords was an Arizona state senator and Kelly was a NASA astronaut. Kelly was married with two daughters, and Giffords had a boyfriend.

When the committee met in Arizona the following year, both were single. They hiked in the Grand Canyon together and struck up a friendship that eventually blossomed into romance in November 2004, when Giffords invited him to join her on a tour of the Arizona State Prison.

"She had it all," Kelly told the New York Times in their wedding announcement. "Beautiful, smart, hard working, balanced, fun to be with, and she laughed at my jokes."

Giffords was also smitten, according to family friend Robert Reich.

"I remember Gabby telling me she met this fellow, and then she giggled," Reich told Parade magazine in 2017. "I said, 'He must be tall and dark and very handsome,' and she laughed and said, 'No. He's short and bald, and I love him.'"

Giffords wore a recycled Vera Wang dress from a family friend, and the reception consisted of biodegradable decor.

The couple remained long-distance after their wedding, with Giffords working in Arizona and Washington and Kelly in Houston at the Johnson Space Center.

Kelly led a seven-member crew in installing a Japanese Pressurized Module laboratory and a robotic arm in the International Space Station.

In Congress, Giffords served on the Armed Services Committee and the Science, Space, and Technology Committee.

Six people died and 20 were injured when a gunman opened fire at Giffords as she was connecting with constituents outside of a Safeway grocery store.

Kelly was in Houston when he received the call notifying him that his wife had been shot. He rushed to Tuscon on a friend's private plane along with his daughters, Claudia and Claire.

Some news outlets erroneously reported that Giffords had died. For about 20 minutes, until the reports were corrected, he believed his wife was gone.

"I just, you know, walked into the bathroom, and you know, broke down," Kelly told ABC's Diane Sawyer in 2011. "To hear that she died is just, it's devastating for me."

Kelly cancelled his astronaut training for an upcoming mission to keep vigil at her bedside. He told ABC News that Giffords would play with his wedding ring — a familiar gesture that showed she knew he was there.

"If I hold her hand, she'll play with my wedding ring," he said. "She'll move it up and down my finger. She'll take it off ... She'll put it on her own finger. She'll move it to her thumb. And then she can put it back on my finger. The reason why I know that that means she recognizes me is because she's done that before. She'll do that if we're sitting in a restaurant. She'll do the same exact movements."

Giffords began making enough strides in her recovery for Kelly to return to his work as an astronaut.

He launched into space on May 16, 2011, commanding a mission to deliver the Alpha Magnetic Spectrometer and other supplies to the ISS. Giffords was in attendance to watch the launch from a private area reserved for friends and family. Kelly also arranged for roses to be delivered to Giffords and his two daughters eight minutes after takeoff, when the shuttle entered the Earth's orbit.

Giffords was met with a standing ovation from both sides of the aisle.

"The #Capitol looks beautiful and I am honored to be at work tonight," Giffords tweeted.

"I know what it takes to be a Woman of the Year," he said in his acceptance speech. " I see it in her every day."

The book chronicles their love story, Giffords' challenging recovery, and their hopes for the country as they move forward from the attack.

In an excerpt featured on NPR, Kelly writes about how connected they remain despite Giffords' difficulty communicating.

"While Gabby struggles for words, coping with a constant frustration that the rest of us can't fathom, I still know what she's thinking much of the time," he wrote. "Yes, her words come haltingly or imperfectly or not at all, but I can still read her body language. I still know the nuances of that special smile of hers. She's still contagiously animated and usually upbeat, using her one good hand for emphasis. And she still knows what I'm thinking, too."

The Ultralight Aircraft Smuggling Prevention Act of 2012 gave law enforcement greater authority to combat illicit drug trafficking on US borders.

Kelly and Giffords founded the political action committee in 2013 to "encourage elected officials to stand up for solutions to prevent gun violence and protect responsible gun ownership."

The couple also went on a nationwide tour speaking to lawmakers and audiences about stricter gun laws.

"I've been shot at a number of times in war in Iraq and Kuwait, and Gabby's been shot at and hit," Kelly told the Washington Post in 2013. "We've talked about these things. She had her office shot out before somebody tried to assassinate her. When her office door was shot out, she didn't quit and run and hide. She went back to work, and almost lost her life over it. Despite that, she's back at work now. Some things are important enough that you take that kind of risk."

Read more: NASA astronaut Mark Kelly, whose wife Gabby Giffords was shot in the head, still owns guns. He says Congress could do a lot more to keep people safe.

"Speaking is difficult for me. But come January, I want to say these two words: 'Madam President,'" she said to thunderous applause.

Giffords didn't speak at the rally, but she did tweet a photo with "Hamilton" creator Lin-Manuel Miranda captioned "If you stand for nothing, what will you fall for?"

"One thing I realized early on was that Gabby needed me to help her through this, she needed an advocate," he said in the campaign video. "And the thing I have to do for my wife is to be able to think clearly and make good decisions."

He continued, "What I learned from my wife is how you use policy to improve people's lives."

Read more: Former astronaut Mark Kelly announces he's running for John McCain's Senate seat in an emotional ad featuring his wife Gabby Giffords

Kelly unseated Republican Martha McSally and helped Democrats regain control of the Senate.

"You were by my side when I took my oath of office nearly 14 years ago. I'm so excited to be by yours today as you're sworn in as our next Arizona Senator," Giffords wrote on Twitter, sharing an old photo of her own swearing-in ceremony.

"As I sat waiting for information about @SenMarkKelly's safety today, I couldn't stop thinking about what you must have gone through 10 years ago this week," Giffords wrote on Twitter. "I'm so glad you and your staff are safe. I love you, sweetie."

She also wrote an op-ed for the New York Times on the 10th anniversary of the shooting that nearly ended her life about resilience in the aftermath of the Capitol riot.

"The fear I felt as I waited was a terrifying echo of the fear he endured exactly a decade ago this week," she wrote. "It echoed the dread that millions of parents have experienced when they have received reports of school lockdowns and neighborhood shootings. This time that fear was shared by the families of so many elected officials and their teams and Capitol staff as the world watched while the walls of Congress were breached."