NASA Chief of the Astronaut Office Peggy Whitson, left, STS-135 mission Pilot Doug Hurley, second from left, NASA Administrator Charles Bolden, and Deputy Chief of Flight Crew Operations Directorate Brian Kelly, right, talk under the space shuttle Atlantis at the Kennedy Space Center Shuttle Landing Facility (SLF) shortly after Hurley and the rest of the STS-135 crew landed in Atlantis early Thursday morning, July 21, 2011, in Cape Canaveral, Fla. Overall, Atlantis spent 307 days in space and traveled nearly 126 million miles during its 33 flights. Atlantis, the fourth orbiter built, launched on its first mission on Oct. 3, 1985. Photo Credit: (NASA/Bill Ingalls)

CAPE CANAVERAL, Fla. -- At NASA Kennedy Space Center's Shuttle Landing Facility in Florida, the STS-134 crew members arrive for final preparations for shuttle Endeavour's liftoff to the International Space Station. On the tarmac are from left (front row) Mission Specialist Michael Fincke and Commander Mark Kelly. Walking behind (from left) are Shuttle Launch Director Mike Leinbach, NASA astronaut Scott Kelly and Deputy Chief of Flight Crew Operations, Brian Kelly. Endeavour and its crew will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank and additional spare parts for the Dextre robotic helper to the station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

jsc2018e076665 (Aug. 23, 2018) --- Vice President Mike Pence and NASA Administrator Jim Bridenstine visit the Sonny Carter Training Center (Neutral Buoyancy Lab) at NASA’s Johnson Space Center on Aug. 23, 2018. Pence and Bridenstine spoke with astronaut Suni Williams, and astronaut candidates Jonny Kim, Warren "Woody" Hoburg and Loral O’Hara poolside. While in the Test Control Room, they joined Flight Operations Director Brian Kelly and talked with astronauts Victor Glover and Nicole Mann as they practiced spacewalk tasks underwater.

jsc2018e076666 (Aug. 23, 2018) --- Vice President Mike Pence and NASA Administrator Jim Bridenstine visit the Sonny Carter Training Center (Neutral Buoyancy Lab) at NASA’s Johnson Space Center on Aug. 23, 2018. Pence and Bridenstine spoke with astronaut Suni Williams, and astronaut candidates Jonny Kim, Warren "Woody" Hoburg and Loral O’Hara poolside. While in the Test Control Room, they joined Flight Operations Director Brian Kelly and talked with astronauts Victor Glover and Nicole Mann as they practiced spacewalk tasks underwater.

jsc2018e076664 (Aug. 23, 2018) --- Vice President Mike Pence and NASA Administrator Jim Bridenstine visit the Sonny Carter Training Center (Neutral Buoyancy Lab) at NASA’s Johnson Space Center on Aug. 23, 2018. Pence and Bridenstine spoke with astronaut Suni Williams, and astronaut candidates Jonny Kim, Warren "Woody" Hoburg and Loral O’Hara poolside. While in the Test Control Room, they joined Flight Operations Director Brian Kelly and talked with astronauts Victor Glover and Nicole Mann as they practiced spacewalk tasks underwater.