- UNDATED FILE PHOTO - A close-up view of the lunar rocks contained in the second Apollo 11 sample return container are shown in this undated file picture. The rock box was opened for the first time in the Vacuum Laboratory of the Manned Spacecraft Center's Lunar Receiving Laboratory, on August 5, 1969. The 30th anniversary of the Apollo 11 mission is July 16 (launch) and July 20 (landing on the moon). 

- FILE PHOTO JULY 1969 - Former U.S. President Richard M. Nixon welcomes the Apollo 11 astronauts aboard the U.S.S. Hornet in the Pacific Ocean in this July 1969 file photo. Already confined to the Mobile Quarantine Facility are, from left: Neil A. Armstrong, commander; Michael Collins, command module pilot; and Edwin E. Aldrin Jr., lunar module pilot. The 30th anniversary of the Apollo 11 mission is July 16 (launch) and July 20 (landing on the moon). 

Computer scientist Margaret Hamilton (L) receives the Presidential Medal of Freedom from U.S. President Barack Obama during a ceremony in the East Room of the White House in Washington, U.S., November 22, 2016. REUTERS/Carlos Barria