ALT View of Tethys, the small cratered moon of Saturn that is quarter-illuminated by the sun, as seen from a distance of about 28,000 miles (44,500 kilometers) by NASA's Cassini spacecraft in August 2015.

ALT Astronaut Neil A. Armstrong receives the first Congressional Space Medal of Honor from President Jimmy Carter, assisted by Captain Robert Peterson. Armstrong, one of six astronauts to be presented the medal during ceremonies held in the Vehicle Assembly Building (VAB), was awarded for his performance during the Gemini 8 mission and the Apollo 11 mission when he became the first human to set foot upon the Moon.

ALT During a tour of Kennedy Space Center, President Jimmy Carter, smiling, with wife Rosalynn and daughter Amy, listen to center director Lee R. Scherer discuss a crawler-transporter model on the table in front of them. They are wearing hard hats with the NASA "worm" logo, and each Carter family member's name. Credit: NASA

ALT An archival photo from 1977 shows three men dressed in suits. The man at the left is Voyager project scientist Ed Stone. He is dark-haired and smiling as he shakes the hand of the man in the middle, President Jimmy Carter. Carter faces away from the camera. At right, a third man in a pinstripe suit and glasses smiles toward the men shaking hands.

ALT This image is of President Jimmy Carter's letter that was included on the Voyager spacecraft's Golden Record. Three paragraphs of black typeface are set against a white page. The third paragraph, Carter's message to the cosmos, is indented. Below the paragraphs is Jimmy Carter's signature, labeled President of the United States. The bottom left corner of the page includes a notation that reads: The White House, June 16, 1977

ALT Apollo 8 astronauts Frank Borman. Bill Anders, and Jim Lovell, as well as the commanding officer of the recovery ship U.S.S. Yorktown walk the red carpet of the flight deck after splashdown recovery in the Pacific Ocean on Dec 27, 1968.

ALT Biologist Elaine Muñoz wears protective gear as she transfers an Apollo 11 lunar sample in the glove box in the Lunar Biological Laboratory. NASA / Harry Zabower

ALT Photograph of the Mars meteorite specimen ALH84001, found during a snowmobile ride December 27, 1984, in the Far Western Icefield of Allan Hills in Antarctica. It is on a white background next to a one centimeter cube.