Gage Skidmore/CC BY-SA 3.0

Mark Kelly and Gabrielle Giffords in Phoenix in 2016.

Former NASA astronaut Mark Kelly is running for Arizona’s U.S. Senate seat in 2020.

Kelly, 54, is a top Democratic recruit to take on Republican Martha McSally in one of the most closely contested Senate races of the 2020 election.

McSally is a former Republican congresswoman who was appointed to McCain's seat last year after she narrowly lost to Democrat Kyrsten Sinema. McSally leaned heavily on her record as the first woman to fly a combat mission as a fighter pilot, but she was hurt by her embrace of President Donald Trump.

The 2020 election will decide who finishes the last two years of McCain's term. The winner would have to run again for a full six-year term in 2022.

The video announcement released Tuesday morning details Kelly’s early life and time as a NASA astronaut and Navy captain.

“I flew 39 combat missions in operation desert storm over Iraq and Kuwait," he said.

It also heavily features his wife — former U.S. Congresswoman Gabrielle Giffords, who was seriously injured in a 2011 shooting that killed six people in Tucson.

If Kelly is nominated, the race would pit a Navy veteran and astronaut against a trailblazing Air Force pilot in the contest to replace McCain, a legendary Navy flyer who was famously shot down and held captive.

Kelly’s political experience lies mostly in lobbying lawmakers for gun control with his wife after she was shot.

He told Capitol Media Services on Tuesday his plan is to run as a centrist.

“I don’t look at this through a partisan lens. I think Arizonans need people who are independent, or at least independent-minded," he said.

Associated Press contributed to this report.