NASA Astronaut Joe Acaba, center, moderates a panel discussion with NASA's 2013 astronaut candidates, from left, Christina M. Hammock, Andrew R. Morgan, Victor J. Glover, Jessica U. Meir, Tyler N. "Nick" Hague, Josh A. Cassada, Anne C. McClain, and, Nicole Aunapu Mann, at the annual White House State of Science, Technology, Engineering, and Math (SoSTEM) address, Wednesday, Jan. 29, 2014, in the South Court Auditorium in the Eisenhower Executive Office Building on the White House complex in Washington. Photo Credit: (NASA/Bill Ingalls)

Dr. John P. Holdren, Assistant to the President for Science and Technology and Director of the White House Office of Science & Technology Policy, center, poses for a group photograph with NASA's 2013 astronaut candidates, from left, Josh A. Cassada, Nicole Aunapu Mann, Jessica U. Meir, Tyler N. "Nick" Hague, Holdren, Victor J. Glover, Christina M. Hammock, Andrew R. Morgan, and, Anne C. McClain at the annual White House State of Science, Technology, Engineering, and Math (SoSTEM) address, Wednesday, Jan. 29, 2014, in the South Court Auditorium in the Eisenhower Executive Office Building on the White House complex in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Astronaut Joe Acaba, center, moderates a panel discussion with NASA's 2013 astronaut candidates, from left, Christina M. Hammock, Andrew R. Morgan, Victor J. Glover, Jessica U. Meir, Tyler N. "Nick" Hague, Josh A. Cassada, Anne C. McClain, and, Nicole Aunapu Mann, at the annual White House State of Science, Technology, Engineering, and Math (SoSTEM) address, Wednesday, Jan. 29, 2014, in the South Court Auditorium in the Eisenhower Executive Office Building on the White House complex in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA Astronaut Joe Acaba, center, moderates a panel discussion with NASA's 2013 astronaut candidates, from left, Christina M. Hammock, Andrew R. Morgan, Victor J. Glover, Jessica U. Meir, Tyler N. "Nick" Hague, Josh A. Cassada, Anne C. McClain, and, Nicole Aunapu Mann, at the annual White House State of Science, Technology, Engineering, and Math (SoSTEM) address, Wednesday, Jan. 29, 2014, in the South Court Auditorium in the Eisenhower Executive Office Building on the White House complex in Washington. Photo Credit: (NASA/Bill Ingalls)

A student ask a question to NASA Astronaut Joe Acaba, center, and NASA's 2013 astronaut candidates, from left, Christina M. Hammock, Andrew R. Morgan, Victor J. Glover, Jessica U. Meir, Tyler N. "Nick" Hague, Josh A. Cassada, Anne C. McClain, and, Nicole Aunapu Mann, at the annual White House State of Science, Technology, Engineering, and Math (SoSTEM) address, Wednesday, Jan. 29, 2014, in the South Court Auditorium in the Eisenhower Executive Office Building on the White House complex in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA personnel watch as a wreath is laid at the Tomb of the Unknowns by NASA Administrator Charles Bolden as part of NASA's Day of Remembrance, Friday, Jan. 31, 2014, at Arlington National Cemetery. The wreaths were laid in memory of those men and women who lost their lives in the quest for space exploration. Photo Credit: (NASA/Bill Ingalls)

Dr. John P. Holdren, Assistant to the President for Science and Technology and Director of the White House Office of Science & Technology Policy, talks with NASA's 2013 astronaut candidates at the annual White House State of Science, Technology, Engineering, and Math (SoSTEM) address, Wednesday, Jan. 29, 2014, in the South Court Auditorium in the Eisenhower Executive Office Building on the White House complex in Washington. Photo Credit: (NASA/Bill Ingalls)

NASA personnel and members of the public watch as a wreath is laid at the Tomb of the Unknowns by NASA Administrator Charles Bolden as part of NASA's Day of Remembrance, Friday, Jan. 31, 2014, at Arlington National Cemetery. The wreaths were laid in memory of those men and women who lost their lives in the quest for space exploration. Photo Credit: (NASA/Bill Ingalls)