May 28, 2008, file photo: Space shuttle Discovery commander Mark Kelly, right, gestures as he walks with his twin brother astronaut Scott Kelly, left, and mission specialist Ron Garan, after arrival at Kennedy Space Center in Cape Canaveral, Fla. Terry Renna/AP hide caption

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Gloria Giffords (center), Rep. Gabrielle Gifford's mother, talks with her daughter on the flight to Houston. Capt. Mark Kelly (far left), the representative's husband, talks with Tracy Culbert (center right), a nurse. Office of U.S. Rep. Gabrielle Giffords hide caption

itoggle caption Office of U.S. Rep. Gabrielle Giffords

In this photo provided by the office of Rep Gabrielle Giffords, Giffords' husband, Mark Kelly, stands with his wife as she looks from her bed at the Santa Catalina Mountains while on an outdoor deck at University Medical Center in Tucson, Ariz., Thursday, Jan. 20, 2011. Anonymous/AP hide caption

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A makeshift memorial outside the University Medical Center in Tucson includes candles and this photo of Rep. Gabrielle Giffords with supporters. John Moore/Getty Images hide caption

itoggle caption John Moore/Getty Images