Astronaut husband of Rep. Giffords to retire

Astronaut Mark Kelly, the husband of Rep. Gabrielle Giffords (D-Ariz.), announced Tuesday he would retire Oct. 1. 

Kelly, a captain in both NASA and the Navy, recently piloted the final flight of the Space Shuttle Endeavour. Giffords, who is recovering from a January assassination attempt, made her first public appearance since the shooting to watch the shuttle's liftoff. 

On Tuesday, Kelly said on his Facebook page that now he wanted to be there for Giffords. 

"Gabrielle is working hard every day on her mission of recovery," he wrote. "I want to be by her side. Stepping aside from my work in the Navy and at NASA will allow me to be with her and with my two daughters. I love them all very much and there is no doubt that we will move forward together. After some time off, I will look at new opportunities and am hopeful that one day I will again serve our country." 

Though the shuttle program is ending with a final flight later next month, Kelly said he was not worried about the future of the space program — even as he was leaving it. 

"I know that as our space program evolves, there are those who will question NASA's future," he said. "I am not among them. There isn't a group more dedicated to its mission or more capable than the outstanding men and women of NASA. Exploration is a critical component of what makes our country great. We will continue to explore and NASA will continue to lead that effort." 

Kelly added that he enjoyed his more than 25-year career. 

"From the day I entered the United States Merchant Marine Academy in the summer of 1982 to the moment I landed the Space Shuttle Endeavour three weeks ago, it has been my privilege to advance the ideals that define the United States of America," he wrote. 

Giffords's office staff spread the news on her Twitter page, tweeting to her followers "Thank you for your service Mark!" 

Giffords was released from a Houston hospital last week, moving into a home Kelly has there.

Moments after Kelly announced his retirement Tuesday, book publisher Scribner announced it had signed a deal to publish a book co-authored by Kelly and Giffords. The book is set to detail the early phrases of the couple's relationship, as well as how they've been affected by the Jan. 8 Tucson, Ariz. shooting.

This story was updated with new information at 1:25 p.m.