Shuttle commander retires
Washington - Mark Kelly, the US astronaut who commanded the final flight by the shuttle Endeavour, announced on Tuesday he is retiring to spend more time with his lawmaker wife as she recovers from a gunshot wound to the head.
"Today, I am humbled to announce that after 25 years of service to our country, I am retiring from the United States Navy and leaving Nasa, effective October 1," Kelly said in a statement.
"As life takes unexpected turns we frequently come to a crossroads. I am at this point today. Gabrielle is working hard every day on her mission of recovery. I want to be by her side," he said.
Kelly, 47, took on a high-profile role in the US space agency in the aftermath of the January shooting, which gravely wounded his wife Gabrielle Giffords at a political meeting in Arizona.
His painstaking decision to command Endeavour's final flight - the second to last mission by a US space shuttle before the programme ends later this year - came as Giffords was busy with a gruelling rehabilitation program, and was supported by his family and many in the American public.
"I will be forever grateful to the Nasa managers who trusted me with this enormous responsibility during such a difficult period in my personal life and to those leaders in the United States Navy who prepared me to handle these challenging times," he said in his statement.
Last week Giffords was discharged from the hospital, five months after she was shot in the head at point-blank range in an attack that shocked the nation.
She has moved into her husband's home in League City, Texas and will continue outpatient therapy, her office said.
Six people, including a federal judge and a 9-year-old girl, were killed and 12 others wounded in the January 8 shooting spree.
In March, the alleged shooter, Jared Loughner, was declared mentally unfit to stand trial. Experts found the 22-year-old to be schizophrenic and unable to help in his own defence or understand court proceedings.
Photos of a smiling Giffords - who is battling to regain movement on the right side of her body after a bullet tore through the left side of her brain - were posted on her Facebook page earlier this month.
Her aides have praised her determination but acknowledged she faces a long process of rehabilitation and has difficulty expressing complex thoughts. It remains unknown whether or not she will return to her job as a member of the US Congress.
"Thank you for your service Mark!" read a Twitter message, signed "Team Giffords" and sent from his wife's account.
Kelly said he would consider his next professional move after an unspecified hiatus.
"After some time off, I will look at new opportunities and am hopeful that one day I will again serve our country," he said.