The astronaut husband of wounded Congresswoman Gabrielle Giffords is calling it a career.

FOX News Radio's Jessica Rosenthal reports...

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This announcement comes on the same day that Giffords and Kelly announce that they're collaborating on a memoir.  Scribner will publish the as-yet-untitled book, which will chronicle everything from their individual careers to their long-distance courtship, providing intimate details of their lives that few people know.

A release date has yet to be determined.

As part of House rules, Giffords will not receive an advance, and the deal must be cleared by the House Ethics Committee.  A portion of the authors' net proceeds will be donated to charities benefiting Arizona and Tucson, the city where Giffords was shot in an assassination attempt on January 8th.

Read Captain Mark Kelly's full retirement announcement (made via Facebook) HERE:

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 Oct. 1.

Words cannot convey my deep gratitude for the opportunities I have been given to serve our great nation. 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.

This was not an easy decision. Public service has been more than a job for me and for my family. My brother continues to serve in NASA and in the Navy. My parents are retired police officers. And my wife Gabrielle proudly serves in the U.S. House of Representatives.

Early in my career, I served in Operation Desert Storm, flying combat missions from the aircraft carrier USS Midway. Today, the men and women of the armed forces continue to serve in combat zones throughout the globe. There is no higher calling. These are the people who inspire me with their sacrifice and timeless sense of duty.

In 1996, I began a 15-year career at NASA that has taken me to the International Space Station four times aboard space shuttles Endeavour and Discovery. Recently, I was given the unique opportunity to be the final commander of Endeavour. 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.

I know that as our space program evolves, there are those who will question NASA's future. 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.

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. 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.