NASA Administrator Charles Bolden testifies in front of the Senate Appropriations Committee, Monday, April 11, 2011, at the Dirksen Senate Office Building on Capitol Hill in Washington. Photo Credit: (NASA/Paul E. Alers)

NASA Administrator Charles Bolden testifies in front of the Senate Appropriations Committee, Monday, April 11, 2011, at the Dirksen Senate Office Building on Capitol Hill in Washington. Photo Credit: (NASA/Paul E. Alers)

NASA Administrator Charles Bolden is seen during testimony in front of the Senate Appropriations Committee, Monday, April 11, 2011, at the Dirksen Senate Office Building on Capitol Hill in Washington. Photo Credit: (NASA/Paul E. Alers)

NASA Administrator Charles Bolden, left, speaks with U.S. Sens. Barbara Mikulski, D-Md., center, and Kay Bailey Hutchison, R-Texas, right, prior to his testimony in front of the Senate Appropriations Committee, Monday, April 11, 2011, at the Dirksen Senate Office Building on Capitol Hill in Washington. Photo Credit: (NASA/Paul E. Alers)

NASA Administrator Charles Bolden is seen prior to his testimony in front of the Senate Appropriations Committee, Monday, April 11, 2011, at the Dirksen Senate Office Building on Capitol Hill in Washington. Photo Credit: (NASA/Paul E. Alers)

NASA Administrator Charles Bolden listens to questions during a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

U.S. Sen. Orrin Hatch, R-Utah, testifies at a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

John Frost, Council Member, NASA Aerospace Safety Advisory Panel, testifies at a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

John Frost, Council Member, NASA Aerospace Safety Advisory Panel, testifies at a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

Sen. Richard Shelby, R-Ala., questions NASA Administrator Charles Bolden during a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden testifies at a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden testifies at a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden listens to questions during a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden is seen on a television monitor as he testifies at a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

Sen. George Voinovich, R-Ohio, questions NASA Administrator Charles Bolden during a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

U.S. Sen. Orrin Hatch, R-Utah, left, talks with NASA Administrator Charles Bolden prior to testifying at a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing on the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

Sen. Kay Bailey Hutchinson, R-Texas, questions NASA Administrator Charles Bolden during a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden listens to NASA Associate Administrator for Legislative and Intergovernmental Affairs Seth Statler during a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

Sen. Kay Bailey Hutchinson, R-Texas, listens to NASA Administrator Charles Bolden during a Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee hearing concerning the FY 2011 NASA Budget, Thursday, April 22, 2010 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

U.S. Sen. Barbara Mikulski, D-Md., Chairwoman of the Senate Subcommittee on Commerce, Justice, Science, and Related Agencies of the Appropriations Committee questions NASA Administrator Charles Bolden during a hearing on the FY 2011 NASA Budget, Thursday, April 22, 2011 at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

Sen. Jeanne Shaheen, D-NH, questions NASA Administrator Jim Bridenstine during a US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

Sen. Jerry Moran, R-Kan., chairman of the Subcommittee on Commerce, Justice, Science, and Related Agencies, questions NASA Administrator Jim Bridenstine during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Jim Bridenstine testifies before the US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Jim Bridenstine testifies before the US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Jim Bridenstine testifies before the US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Jim Bridenstine testifies before the US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Jim Bridenstine testifies before the US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Jim Bridenstine testifies before the US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Jim Bridenstine testifies before the US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Jim Bridenstine testifies before the US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Jim Bridenstine testifies before the US Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies during a budget review hearing, Wednesday, May 1, 2019, at the Dirksen Senate Office Building in Washington. Photo Credit: (NASA/Bill Ingalls)