NASA astronaut Harrison Schmitt during his visit to the Lunar Reconnaissance Orbiter (LRO)'s Mission Operation Control Center at NASA's Goddard Space Flight Center in Greenbelt, Md.

Stan Lebar, former Westinghouse Electric program manager, in the Building 28 television studio at NASA's Goddard Space Flight Center in Greenbelt, Md.

The atrium in Building 28 at NASA's Goddard Space Flight Center in Greenbelt, Md.

A person cosplays a storm trooper at the Visitor Center at NASA's Goddard Space Flight Center in Greenbelt, Md. Members of the 501st Legion Star Wars cosplaying group attended a "Yuri's Night" celebration to commemorate the first flight of cosmonaut Yuri Gagarin (April 12, 1961) and the first orbital flight of a space shuttle (April 12, 1981).

The Delta rocket on display at the Visitor Center at NASA's Goddard Space Flight Center in Greenbelt, Md. The rocket is illuminated as part of a "Yuri's Night" celebration to commemorate the first flight of cosmonaut Yuri Gagarin (April 12, 1961) and the first orbital flight of a space shuttle (April 12, 1981).

Alberta Moran, one of the first employees of NASA's Goddard Space Flight Center in Greenbelt, Md., and subsequently a longtime volunteer at the Goddard Visitor Center.

Astronaut Piers Sellers at NASA's Goddard Space Flight Center in Greenbelt, Md.

Queen Elizabeth II and NASA Administrator Michael Griffin plant a commemorative tree on the grounds of the visitor's center during a visit to NASA's Goddard Space Flight Center, Tuesday, May 8, 2007, in Greenbelt, Md. The Royal couple's appearance was one of the last stops on a six-day visit to the United States. Photo Credit (NASA/Debbie McCallum)