Retired astronaut Mark Kelly announced Tuesday that he will run for the late Sen. John McCain’s Arizona Senate seat in 2020 to finish the term.

Kelly, who came into the national spotlight when his wife, former Rep. Gabrielle Giffords, was shot in a failed assassination attempt, will seek to take on Sen. Martha McSally, R-Ariz., who was appointed to McCain’s seat last year after she was narrowly defeated by now-Sen. Kyrsten Sinema for former Sen. Jeff Flake’s seat.

2020 SENATE RACES

“My next mission… #FullSpeedAhead #ForArizona,” Kelly tweeted, sharing a campaign video.

“I care about people. I care about the state of Arizona. I care about this nation,” Kelly said in the video posted to his Twitter account Tuesday. “So because of that, I’ve decided I’m launching a campaign for the United States Senate.”

The video, which runs more than four minutes, gives a detailed account of Kelly’s experience as a former Navy pilot, an astronaut, and being Giffords' husband.

“The thing I have to do for my wife is to be able to think clearly and make good decisions…You gotta move ahead and try to make a difference in the world,” Kelly said. “What I learned from my wife is how you use policy to improve people’s lives.”

Kelly listed “affordable health care,” job growth, the economy, and climate change as major issues that Arizonans will face in the coming years.

REP. MARTHA MCSALLY APPOINTED BY ARIZONA GOVERNOR TO SENATE SEAT HELD BY JOHN MCCAIN

“Solving some of the hardest problems requires one thing — and that’s teamwork,” he said. “Partisanship and polarization and gerrymandering and corporate money have ruined our politics and it’s divided us.”

He added: “We’ve seen this retreat from science and data and facts and if we don’t take these issues seriously, we can’t solve these problems.”

The video concludes with Kelly and Giffords on the couch, speaking together.

“So please join us. Damn the torpedoes. Full speed ahead,” they say.

Kelly and Giffords have for years pushed Congress to enact gun control measures with little success. They shifted their focus to state legislatures in recent years, helping to strengthen background checks and domestic violence protections, among other modest protections.

If Kelly becomes the Democratic nominee, he will be up against McSally — also a veteran, having served in the Air Force as a pilot. 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.

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Rep. Ruben Gallego of Phoenix is also considering a Senate run, which would likely set up a tough fight for the Democratic nomination.

Former Arizona Attorney General Grant Woods, a lifelong Republican who became a Democrat and a fierce critic of Trump, announced last week that he won't run, saying he didn't want to fight in a contested Democratic primary.

The Associated Press contributed to this report.