Gabby Giffords, announced Tuesday that he will run in 2020 for the Arizona U.S. Senate seat held by Republican Martha McSally.
Kelly, 54, announced the bid in a video posted to his Twitter account.
Mark Kelly TWEET My next mission... F ullSpeedAheadF orArizona
"I always knew that I was going to serve this country in some way," said Kelly, who served in the Navy during the Gulf War and was tapped to become a NASA pilot in 1996.
Kelly, a Democrat, highlighted his career as an astronaut in the four-minute video, which he captioned as "my next mission." It begins with him recounting his first experience witnessing a sunrise from a space shuttle.
"It becomes pretty obvious pretty early when you get into space that were all in this together," he said.
Kelly, who has never held political office, became politically active after his wife, Rep. Gabby Giffords, was shot in a 2011 assassination attempt at a Tucson supermarket. Six people died in the attack.
Giffords, who was shot in the head, resigned from Congress in 2012 to focus on her recovery. In 2013, Kelly and Giffords launched a nonprofit supporting gun control.
In the 2018 midterms, McSally lost to Democrat Kyrsten Sinema in her bid for the seat of retiring GOP Sen. Jeff Flake. Republican Gov. Doug Ducey appointed McSally to fill the Senate seat that had been vacated by the death of John McCain in August.
Kelly may not have the field to himself, as competition from his own party may soon be on the horizon. Rep. Ruben Gallego, D-Ariz., said in a tweet that he is "looking seriously at running for the U.S. Senate in 2020," adding that he will make an announcement "soon."
Galleg TWEET Ive made no secret of the fact that Im looking seriously at running for the U.S. Senate in 2020, and that hasnt changed. Ill be making a final decision and announcement soon.