Former astronaut Mark Kelly announces run for US Senate

Kelly said in Tuesday’s announcement that his decision to run was partially inspired by his wife, who in 2011 survived an attempted assassination in Tuscon.

“One thing I realized early on was, you know, that Gabby needed me to help her through this -- she needed an advocate. The thing I need to do for my wife  is to be able to move ahead,” Kelly said. “What I learned from my wife is how you use policy to improve people’s lives.”

Kelly, 54, served as a combat pilot in the U.S. Navy, flying 39 combat missions over Iraq and Kuwait during Desert Storm, before he and his twin brother, Scott, were chosen in 1996 to become NASA Shuttle pilots. The brothers are the only siblings who have traveled in space.

Kelly in 2001 flew his first mission to space aboard the Space Shuttle Endeavor. He’s since flown three other missions into space and spent more than 50 days off-planet.

Kelly retired from NASA in 2011, after his wife was shot, and moved to Tucson.

KNXV-TV reported that although he's never before held public office, Kelly became "a visible advocate for gun control" in the wake of the attack on Giffords. In 2013, he founded a pro-gun control political action committee, Americans for Responsible Solutions, according to KOLD-TV.

Kelly plans to run for the U.S. Senate seat previously held by the late Republican Sen. John McCain and currently held by Republican Martha McSally, KOLD-TV reported. McSally was appointed late last year to represent Arizona's Second District after McCain's original successor, John Kyl, announced his plans to retire, according to The Arizona Republic.

Kelly is considered a top Democratic recruit to take on McSally in one of the most closely contested Senate races of the 2020 election.

Kelly lives in Tuscon with his wife.

The Associated Press contributed to this report.