This Dec. 2012 photo provided by Jonathan Clark shows Dr. Jonathan Clark, husband of Columbia astronaut Laurel Clark, stands with his son, Iain Clark, 18, in Arizona. Clark's wife and six other astronauts, Commander Rick Husband, co-pilot William McCool, Kalpana Chawla, Michael Anderson, Dr. David Brown and Israeli Ilan Ramon, were killed in the final minutes of their 16-day scientific research mission aboard the space shuttle Columbia on Feb. 1, 2003. Iain is set to graduate this spring from a boarding school in Arizona; he wants to study marine biology at a university in Florida.(AP Photo/Jonathan Clark)

FILE - This photo provided by NASA in June 2003 shows STS-107 crew members,from the left (bottom row), wearing red shirts to signify their shift’s color, are astronauts Kalpana Chawla, mission specialist; Rick D. Husband, mission commander; Laurel B. Clark, mission specialist; and Ilan Ramon, payload specialist. From the left (top row), wearing blue shirts, are astronauts David M. Brown, mission specialist; William C. McCool, pilot; and Michael P. Anderson, payload commander. The astronauts were killed on Feb. 1, 2003, in the final minutes of their 16-day scientific research mission aboard Columbia. Altogether, 12 children lost a parent aboard Columbia. The youngest is now 15, the oldest 32. (AP Photo/NASA, File)

This Dec. 2012 photo provided by Jonathan Clark shows Iain Clark at an indoor skydiving center in Denver. Clark's mother, Dr. Laurel Clark, and six other astronauts, Commander Rick Husband, co-pilot William McCool, Kalpana Chawla, Michael Anderson, Dr. David Brown and Israeli Ilan Ramon, were killed in the final minutes of their 16-day scientific research mission aboard the space shuttle Columbia on Feb. 1, 2003. Iain is set to graduate this spring from a boarding school in Arizona; he wants to study marine biology at a university in Florida. (AP Photo/Jonathan Clark)