Solar Dynamics Observatory Program Manager, left, describes the SDO project to Prince Philip in front of the spacecraft clean tent. Photo Credit: (NASA/Chris Gunn)

Prince Philip, left, speaks with veteran space walkers John M. Grunsfeld, center, and Michael J. Massimino at NASA's Goddard Space Flight Center. Photo Credit: (NASA/Chris Gunn)

Prince Philip, left, asks astronauts K. Megan McArthur, Commander Scott D. Altman and Gregory C. Johnson, pilot details about the STS-125 mission. Photo Credit: (NASA/Chris Gunn)

Preston Burch, left, Hubble Spece Telescope Program Manager presents Prince Philip with three solar cells returned from space during the first HST servicing mission. Photo Credit: (NASA/Chris Gunn)

Queen Elizabeth II and Prince Philip, The Duke of Edinburgh look on as Goddard employees demonstrate “Science on a Sphere.” This system, developed by the National Oceanic and Atmospheric Administration (NOAA), uses computers and four video projectors to display animated images on the outside of a 6-foot diameter sphere. Photo Credit: (NASA/Pat Izzo)

Prince Philip greets astronauts from STS-125 L to R Andrew J Feustel, Michael T Goode, K. Megan McArthur, Michael J. Massimino, Gregory C. Johnson, and Commander Scott D. Altman. Photo Credit: (NASA/Chris Gunn)

Queen Elizabeth II greets employees on her walk from NASA’s Goddard Space Flight Center mission control to a reception in the center’s main auditorium, Tuesday, May 8, 2007, in Greenbelt, Md. Queen Elizabeth II and her husband, Prince Philip, Duke of Edinburgh, visited the NASA Goddard Space Flight Center as one of the last stops on their six-day United States visit. Photo Credit: (NASA/Bill Ingalls)

Queen Elizabeth II talks with students at a NASA Explorer School Workshop, at NASA's Goddard Spaceflight Center, Tuesday, May 8, 2007, in Greenbelt, Md. Queen Elizabeth II and her husband, Prince Philip, Duke of Edinburgh, visited the NASA Goddard Space Flight Center as one of the last stops on their six-day United States visit. Photo Credit: (NASA/Pat Izzo)

Queen Elizabeth II greets children on her walk from NASA’s Goddard Space Flight Center mission control to a reception in the center’s main auditorium, Tuesday, May 8, 2007, in Greenbelt, Md. Queen Elizabeth II and her husband, Prince Philip, Duke of Edinburgh, visited the NASA Goddard Space Flight Center as one of the last stops on their six-day United States visit. Photo Credit: (NASA/Bill Ingalls)

Employees at NASA's Goddard Space Flight Center wait to greet Queen Elizabeth II, Tuesday, May 8, 2007, in Greenbelt, Md. Queen Elizabeth II and her husband, Prince Philip, Duke of Edinburgh, visited the NASA Goddard Space Flight Center as one of the last stops on their six-day United States visit. Photo Credit: (NASA/Bill Ingalls)

Queen Elizabeth II talks with NASA astronaut Piers Sellers at NASA's Goddard Spaceflight Center, Tuesday, May 8, 2007, in Greenbelt, Md. Queen Elizabeth II and her husband, Prince Philip, Duke of Edinburgh, visited the NASA Goddard Space Flight Center as one of the last stops on their six-day United States visit. Photo Credit: (NASA/Pat Izzo)

Queen Elizabeth II greets employees on her walk from NASA’s Goddard Space Flight Center mission control to a reception in the center’s main auditorium, Tuesday, May 8, 2007, in Greenbelt, Md. Queen Elizabeth II and her husband, Prince Philip, Duke of Edinburgh, visited the NASA Goddard Space Flight Center as one of the last stops on their six-day United States visit. Photo Credit: (NASA/Bill Ingalls)

Queen Elizabeth II speaks with STS-116 astronaut Nicholas Patrick, back to camera, as NASA Administrator Michael Griffin, right, looks on at the NASA's Goddard Space Flight Center, Wednesday, 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/Paul E. Alers)