Hall of Fame astronaut Hank Hartsfield thanks the audience for their applause at the 2011 U.S. Astronaut Hall of Fame ceremony.

Hall of Fame astronaut Hank Hartsfield thanks the audience for their applause at the 2011 U.S. Astronaut Hall of Fame induction ceremony at NASA's Kennedy Space Center Visitor Complex in Florida.

Hall of Fame astronauts and visitors gathered to honor 2011 inductees Karol "Bo" Bobko and Susan Helms. During his 19 years in the astronaut program, Bobko flew on three space shuttle missions and logged more than 386 hours in space. He served as pilot during the first voyage of space shuttle Challenger aboard STS-6 in April 1983 and as commander during the maiden flight of space shuttle Atlantis aboard STS-51J in October 1985. Helms, a five-time space shuttle astronaut, has logged 5,064 hours in space. During her stay onboard the International Space Station as a member of the Expedition-2 crew in 2001, Helms performed a world record 8 hour and 56 minute spacewalk. Bobko and Helms join the ranks of the U.S. Astronaut Hall of Fame bringing the number of space explorers enshrined in the Hall of Fame to 79. Photo Credit: NASA/Jim Grossmann