A wreath honoring Steven R. Nagel is displayed beside his photo at the Space Shuttle Atlantis exhibit at the Kennedy Space Center Visitor Complex.

A wreath honoring former NASA astronaut Steven R. Nagel is displayed beside his photo at the Space Shuttle Atlantis exhibit at the Kennedy Space Center Visitor Complex in Florida.

Nagel died Aug. 21 after a long illness. He was 67 years old. Nagel served as a mission specialist on his first space shuttle flight, STS-51G, in 1985. He was pilot on his second shuttle flight, STS-61A, also in 1985. He commanded his final two flights, STS-37 and STS-55, in 1991 and 1993, respectively. He logged a total of 723 hours in space. To learn more about Nagel's career, visit http://www.nasa.gov/press/2014/august/former-nasa-astronaut-steven-nagel-veteran-of-four-shuttle-flights-dies-at-67/. Photo credit: NASA/Dimitri Gerondidakis