Buzz Aldrin took this iconic image of a bootprint on the Moon during the Apollo 11 moonwalk on July 20, 1969. https://photojournal.jpl.nasa.gov/catalog/PIA24439

S69-35505 (June 1969) --- The prime crews of the Apollo 10 lunar orbit mission and the Apollo 11 lunar landing mission are photographed during an Apollo 10 postflight de-briefing session. Clockwise, from left foreground, are astronauts Michael Collins, Apollo 11 command module pilot; Edwin E. Aldrin Jr., Apollo 11 lunar module pilot; Eugene A. Cernan, Apollo 10 lunar module pilot; Thomas P. Stafford, Apollo 10 commander; Neil A. Armstrong, Apollo 11 commander; and John W. Young, Apollo 10 command module pilot.

This montage depicts the flight crew patches for the manned Apollo 7 thru Apollo 17 missions. The Apollo 7 through 10 missions were basically manned test flights that paved the way for lunar landing missions. Primary objectives met included the demonstration of the Command Service Module (CSM) crew performance; crew/space vehicle/mission support facilities performance and testing during a manned CSM mission; CSM rendezvous capability; translunar injection demonstration; the first manned Apollo docking, the first Apollo Extra Vehicular Activity (EVA), performance of the first manned flight of the lunar module (LM); the CSM-LM docking in translunar trajectory, LM undocking in lunar orbit, LM staging in lunar orbit, and manned LM-CSM docking in lunar orbit. Apollo 11 through 17 were lunar landing missions with the exception of Apollo 13 which was forced to circle the moon without landing due to an onboard explosion. The craft was,however, able to return to Earth safely. Apollo 11 was the first manned lunar landing mission and performed the first lunar surface EVA. Landing site was the Sea of Tranquility. A message for mankind was delivered, the U.S. flag was planted, experiments were set up and 47 pounds of lunar surface material was collected for analysis back on Earth. Apollo 12, the 2nd manned lunar landing mission landed in the Ocean of Storms and retrieved parts of the unmanned Surveyor 3, which had landed on the Moon in April 1967. The Apollo Lunar Surface Experiments Package (ALSEP) was deployed, and 75 pounds of lunar material was gathered. Apollo 14, the 3rd lunar landing mission landed in Fra Mauro. ALSEP and other instruments were deployed, and 94 pounds of lunar materials were gathered, using a hand cart for first time to transport rocks. Apollo 15, the 4th lunar landing mission landed in the Hadley-Apennine region. With the first use of the Lunar Roving Vehicle (LRV), the crew was bale to gather 169 pounds of lunar material. Apollo 16, the 5th lunar landing mission, landed in the Descartes Highlands for the first study of highlands area. Selected surface experiments were deployed, the ultraviolet camera/spectrograph was used for first time on the Moon, and the LRV was used for second time for a collection of 213 pounds of lunar material. The Apollo program came to a close with Apollo 17, the 6th and final manned lunar landing mission that landed in the Taurus-Littrow highlands and valley area. This mission hosted the first scientist-astronaut, Schmitt, to land on the Moon. The 6th automated research station was set up, and 243 ponds of lunar material was gathered using the LRV.

S69-35503 (June 1969) --- Astronaut Eugene A. Cernan (left), lunar module pilot of the Apollo 10 lunar orbit mission, confers with astronaut Edwin E. Aldrin Jr. during an Apollo 10 postflight de-briefing session. Aldrin is the lunar module pilot of the Apollo 11 lunar landing mission.

S69-16402 (29 Dec. 1968) --- Although it was past 2 a.m., a crew of more than 2,000 people were on hand at Ellington Air Force Base to welcome the members of the Apollo 8 crew back home. Astronauts Frank Borman, James A. Lovell Jr., and William A. Anders had just flown to Houston from the pacific recovery area by way of Hawaii. The three crewmen of the historic Apollo 8 lunar orbit mission are standing at the microphones in center of picture. Photo credit: NASA

S69-60662 (December 1969) --- This is the insignia of the Apollo 13 lunar landing mission. The Apollo 13 prime crew will be astronauts James A. Lovell Jr., commander; Thomas K. Mattingly II, command module pilot; and Fred W. Haise Jr., lunar module pilot. Represented in the Apollo 13 emblem is Apollo, the sun god of Greek mythology, symbolizing how the Apollo flights have extended the light of knowledge to all mankind. The Latin phrase Ex Luna, Scientia means "From the Moon, Knowledge." Apollo 13 will be the National Aeronautics and Space Administration's (NASA) third lunar landing mission.

Retracing the Steps of Apollo 15

New View of Apollo 14

S69-34968 (24 May 1969) --- Astronaut Eugene A. Cernan, Apollo 10 lunar module pilot, is seen in this color reproduction taken from a telecast made by the color television camera aboard the Apollo 10 spacecraft during its trans-Earth journey home.

S69-34969 (24 May 1969) --- Astronaut Thomas P. Stafford, Apollo 10 commander, is seen in this color reproduction taken from a telecast made by the color television camera aboard the Apollo 10 spacecraft during its trans-Earth journey home.

Astronaut James Lovell (Apollo 8 Apollo 13), center, flanked by Walt Cunningham (Apollo 7), left, and David Scott (Apollo 9 Apollo 15) responds during the 40th anniversary of the Apollo 11 mission and the walk on the moon press conference, Monday, July 20, 2009, at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

Apollo astronauts from left, Walt Cunningham (Apollo 17), James Lovell (Apollo 8 Apollo 13), David Scott (Apollo 9 Apollo 15), Buzz Aldrin (Apollo 11), Charles Duke (Apollo 16), Thomas Stafford (Apollo 10) and Eugene Cernan (Apollo 17) are seen during the 40th anniversary of the Apollo 11 mission and the walk on the moon press conference, Monday, July 20, 2009, at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

Apollo astronauts from left, Walt Cunningham (Apollo 17), James Lovell (Apollo 8 Apollo 13), David Scott (Apollo 9 Apollo 15), Buzz Aldrin (Apollo 11), Charles Duke (Apollo 16), Thomas Stafford (Apollo 10) and Eugene Cernan (Apollo 17) are seen during the 40th anniversary of the Apollo 11 mission and the walk on the moon press conference, Monday, July 20, 2009, at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

Apollo astronauts from left, Walt Cunningham (Apollo 17), James Lovell (Apollo 8 Apollo 13), David Scott (Apollo 9 Apollo 15), Buzz Aldrin (Apollo 11), Charles Duke (Apollo 16), Thomas Stafford (Apollo 10) and Eugene Cernan (Apollo 17) are seen during the 40th anniversary of the Apollo 11 mission and the walk on the moon press conference, Monday, July 20, 2009, at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

S69-34313 (20 May 1969) --- Astronaut Eugene A. Cernan is shown spinning a water bag to demonstrate the collection of hydrogen bubbles in this color reproduction taken from the fifth telecast made by the color television camera aboard the Apollo 10 spacecraft. When this picture was made the Apollo 10 spacecraft was approximately 175,300 nautical miles from Earth, and only 43,650 nautical miles from the moon. Cernan is the Apollo 10 lunar module pilot. Also, aboard Apollo 10 were astronauts Thomas P. Stafford, commander; and John W. Young, command module pilot.

S69-33999 (18 May 1969) --- A close-up view of the face of astronaut, Thomas P. Stafford, Apollo 10 commander, is seen in this color reproduction taken from the third television transmission made by the color television camera aboard the Apollo 10 spacecraft. When this picture was made the Apollo 10 spacecraft was on a trans-lunar course, and was already about 36,000 nautical miles from Earth. Also, aboard Apollo 10 were astronauts John W. Young, command module pilot, and Eugene A. Cernan, lunar module pilot.

Apollo 6 (AS-502) Pacific Recovery

Apollo 6 (AS-502) Pacific Recovery

Apollo 6 (AS-502) Pacific Recovery

Apollo 6 (AS-502) Pacific Recovery

Apollo 6 (AS-502) Pacific Recovery

Apollo 6 (AS-502) Pacific Recovery

S69-27915 (11 March 1969) --- Aerial view at Launch Complex 39, Kennedy Space Center, showing a close-up of the 363-feet tall Apollo 10 (Spacecraft 106/Lunar Module 4/Saturn 505) space vehicle on its way to Pad B. The Saturn V stack and its mobile launch tower are atop a huge crawler-transporter. The Apollo 10 flight is scheduled as a lunar orbit mission. The Apollo 10 crew will be astronauts Thomas P. Stafford, commander; John W. Young, command module pilot; and Eugene A. Cernan, lunar module pilot.

The audience is seen while a video about the Apollo 8 mission is shown on monitors during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

The Washington National Cathedral Choir performs a choral performance of Apollo 8's Christmas Eve broadcast during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

The Washington National Cathedral Choir performs a choral performance of Apollo 8's Christmas Eve broadcast during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

S69-27089 (11 March 1969) --- Overall view of Pad B, Launch Complex 39, Kennedy Space Center, showing the Apollo 10 (Spacecraft 106/Lunar Module-4/Saturn 505) space vehicle during a Countdown Demonstration Test. The Apollo 10 flight is scheduled as a lunar orbit mission. The Apollo 10 crew will be astronauts Thomas P. Stafford, commander; John W. Young, command module pilot; and Eugene A. Cernan, lunar module pilot.

Gerry Griffin, Apollo flight director, makes remarks during the Apollo 11 50th Gala, pressented by Northrop Grumman, inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex on July 16, 2019

This view of the back side of the Moon was captured by the Apollo 16 mission crew. The sixth manned lunar landing mission, the Apollo 16 (SA-511), carrying three astronauts: Mission Commander John W. Young, Command Module pilot Thomas K. Mattingly II, and Lunar Module pilot Charles M. Duke, lifted off on April 16, 1972. The Apollo 16 continued the broad-scale geological, geochemical, and geophysical mapping of the Moon’s crust, begun by the Apollo 15, from lunar orbit. This mission marked the first use of the Moon as an astronomical observatory by using the ultraviolet camera/spectrograph which photographed ultraviolet light emitted by Earth and other celestial objects. The Lunar Roving Vehicle, developed by the Marshall Space Flight Center, was also used. The mission ended on April 27, 1972.

S69-25861 (3 March 1969) --- The Apollo 9 (Spacecraft 104/Lunar Module 3/ Saturn 504) space vehicle is launched from Pad A, Launch Complex 39, Kennedy Space Center (KSC) at 11 a.m. (EST), March 3, 1969. Aboard the spacecraft are astronauts James A. McDivitt, commander; David R. Scott, command module pilot; and Russell L. Schweickart, lunar module pilot. The Apollo 9 mission will evaluate spacecraft lunar module systems performance during manned Earth-orbital flight. Apollo 9 is the second manned Saturn V mission.

S69-25862 (3 March 1969) --- Framed by palm trees in the foreground, the Apollo 9 (Spacecraft 104/Lunar Module 3/ Saturn 504) space vehicle is launched from Pad A, Launch Complex 39, Kennedy Space Center (KSC) at 11 a.m. (EST), March 3, 1969. Aboard the spacecraft are astronauts James A. McDivitt, commander; David R. Scott, command module pilot; and Russell L. Schweickart, lunar module pilot. The Apollo 9 mission will evaluate spacecraft lunar module systems performance during manned Earth-orbital flight. Apollo 9 is the second manned Saturn V mission.

S69-25478 (23 Feb. 1969) --- These three astronauts are the prime crew of the Apollo 9 Earth-orbital space mission. Left to right, are Russell L. Schweickart, lunar module pilot; David R. Scott, command module pilot; and James A. McDivitt, commander. In the right background is the Apollo 9 space vehicle on Pad A, Launch Complex 39, Kennedy Space Center (KSC). They are pausing momentarily during training for their scheduled 10-day mission.

Astronaut James Lovell (Apollo 8 Apollo 13) gestures during the 40th anniversary of the Apollo 11 mission and the walk on the moon press conference, Monday, July 20, 2009, at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

S69-25881 (3 March 1969) --- The Apollo 9 crew leaves the Kennedy Space Center's Manned Spacecraft Operations Building during the Apollo 9 prelaunch countdown. The crewman entered the special transfer van which transported them to their waiting spacecraft at Pad A, Launch Complex 39. Astronaut James A. McDivitt (back to camera) is the commander. McDivitt appears to be inviting astronaut David R. Scott, command module pilot, to step first into van. In background is astronaut Russell L. Schweickart, lunar module pilot. Walking along almost behind Schweickart is astronaut Alan B. Shepard Jr., chief, Astronaut Office, Manned Spacecraft Center. Apollo 9 was launched at 11 a.m. (EST), March 3, 1969, on a 10-day Earth-orbital mission.

S67-50903 (9 Nov. 1967) --- The Apollo 4 (Spacecraft 017/Saturn 501) space mission was launched from Pad A, Launch Complex 39, Kennedy Space Center, Florida. The liftoff of the huge 363-feet tall Apollo/Saturn V space vehicle was at 7:00:01 a.m. (EST), Nov. 9, 1967. The successful objectives of the Apollo 4 Earth-orbital unmanned space mission obtained included (1) flight information on launch vehicle and spacecraft structural integrity and compatibility, flight loads, stage separation, subsystem operation, emergency detection subsystem, and (2) evaluation of the Apollo Command Module heat shield under conditions encountered on return from a moon mission.

The Washington National Cathedral is seen lit up with space imagery prior to the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

The Washington National Cathedral is seen illuminated during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

The Space Window at the Washington National Cathedral is seen during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

The interior of the Washington National Cathedral is seen illuminated prior to the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

AS12-46-6832 (19 Nov. 1969) --- A close-up view of a lunar mound as photographed during the Apollo 12 extravehicular activity (EVA) on the lunar surface. Astronaut Richard F. Gordon Jr., command module pilot, remained with the Apollo 12 Command and Service Modules (CSM) in lunar orbit while astronauts Charles Conrad Jr., commander, and Alan L. Bean, lunar module pilot, descended in the Lunar Module (LM) to explore the moon.

S68-26668 (June 1968) --- The official emblem of Apollo 7, the first manned Apollo space mission. The crew will consist of astronauts Walter M. Schirra Jr., Donn F. Eisele, and Walter Cunningham. The NASA insignia design for Apollo flights is reserved for use by the astronauts and for the official use as the NASA Administrator may authorize. Public availability has been approved only in the form of illustrations by the various news media. When and if there is any change in this policy, which we do not anticipate, it will be publicly announced.

Gerry Griffin, Apollo flight director, left, presents the Pioneer Award to JoAnn Morgan, retired NASA engineer, during the Apollo 11 50th Gala, on July 16, 2019. The gala, presented by Northrop Grumman, was held inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Comples in Florida. Morgan was the first woman engineer on console at Kennedy Space Center and the only woman in the firing room during the Apollo 11 launch countdown and launch.

S69-19983 (17 Feb. 1969) --- The Apollo 9 crew is shown suited up for a simulated flight in the Apollo Mission Simulator at the Kennedy Space Center (KSC). Left to right are astronauts James A. McDivitt, commander; David R. Scott, command module pilot; and Russell L. Schweickart, lunar module pilot.

AS12-47-6949 (19-20 Nov. 1969) --- A photograph of the Apollo 12 lunar landing site taken during the extravehicular activity (EVA) of astronauts Charles Conrad Jr., commander; and Alan L. Bean, lunar module pilot. The Apollo 12 Lunar Module (LM) is on the left. Barely visible in the center of the picture, in the shadows on the farside of the crater, is the Surveyor 3 spacecraft. The two spacecraft are about 600 feet apart. Conrad and Bean walked over to Surveyor 3 during their second EVA. The television camera and several other pieces were taken from Surveyor 3 and brought back to Earth for scientific examination. Astronaut Richard F. Gordon Jr., command module pilot, remained with the Command and Service Modules (CSM) in lunar orbit, while astronauts Conrad and Bean descended in the LM to explore the moon. The considerable glare in the picture is caused by the position of the sun. The Apollo tool carrier is the object next to the LM footpad.

AS17-162-24050 (7-19 Dec. 1972) --- Astronaut Eugene A. Cernan appears to be relaxing in this candid photograph taken by a fellow crewman aboard the Apollo 17 spacecraft during the final lunar landing mission in NASA's Apollo program. Also, aboard Apollo 17 were astronaut Ronald E. Evans, command module pilot, and scientist-astronaut Harrison H. "Jack" Schmitt, lunar module pilot. Cernan was the mission commander.

Andy Aldrin, son of Apollo 11 astronaut Buzz Aldrin, introduces Apollo 11 astronaut Michael Collins, during the Apollo 50th Gala, presented by Northrop Grumman. The event was held inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida on July 16, 2019.

S69-36593 (26 May 1969) --- The Apollo 10 astronauts Thomas P. Stafford (center), John W. Young (left) and Eugene A. Cernan (waving) are greeted by Donald E. Stullken (lower left) of the Manned Space Center's (MSC) recovery operations team. The Apollo 10 crew splashed down in the South Pacific recovery area to conclude a successful eight-day lunar orbit mission. Splashdown occurred at 11:53 a.m. (CDT), May 26, 1969, about 400 miles east of American Samoa and about four miles from the prime recovery ship, USS Princeton.

S69-36593 (26 May 1969) --- The Apollo 10 astronauts Thomas P. Stafford (center), John W. Young (left) and Eugene A. Cernan (waving) are greeted by Donald E. Stullken (lower left) of the Manned Space Center's (MSC) recovery operations team. The Apollo 10 crew splashed down in the South Pacific recovery area to conclude a successful eight-day lunar orbit mission. Splashdown occurred at 11:53 a.m. (CDT), May 26, 1969, about 400 miles east of American Samoa and about four miles from the prime recovery ship, USS Princeton.

NASA Kennedy Space Center Director Bob Cabana, far right, serves as moderator for the “Apollo Heroes Panel Discussion” in the IMAX Theater at the Kennedy Space Center Visitor Complex in Florida on July 16, 2019. Panelists are, from left, JoAnn Morgan, the only woman on console in the Launch Control Center for Apollo 11 launch countdown activities; Bob Sieck, Apollo-era launch team member and former space shuttle launch director; and Harrison Schmitt, Apollo 17 astronaut and moonwalker. The panel discussion is one of several events at the visitor complex to honor the 50th anniversary of NASA’s Saturn V/Apollo 11 launch and landing on the Moon.

S67-49447 (9 Nov. 1967) --- Close-up view of the charred heat shield of the Apollo Spacecraft 017 Command Module aboard the USS Bennington. The damage was caused by the extreme heat of reentry. The carrier Bennington was the prime recovery ship for the Apollo 4 (Spacecraft 017/Saturn 501) unmanned, Earth-orbital space mission. Splashdown occurred at 3:37 p.m. (EST), Nov. 9, 1967, 934 nautical miles northwest of Honolulu, Hawaii.

View of Astronaut David R.Scott ,Apollo 9 Command Module pilot, inside the Command Module "Gumdrop" during the Apollo 9 earth-orbital mission. . Film magazine was D,film type was SO-368 Ektachrome with 0.460 - 0.710 micrometers film / filter transmittance response and haze filter,80mm lens.

S69-35099 (21-27 Dec. 1968) --- Astronaut James A. Lovell Jr., Apollo 8 command module pilot, is seen at the Apollo 8 Spacecraft Command Module's Guidance and Navigation station during the Apollo 8 lunar orbit mission. This picture was taken from 16mm motion picture film.

The Lunar Module for Apollo 11 moves from the landing gear fixture and mate to the spacecraft-lunar module adapter.

S69-26148 (6 March 1969) --- This photograph from the second live television transmission from Apollo 9 was made early Thursday afternoon on the fourth day in space. Though of poor quality, this view shows the interior of the Lunar Module "Spider" with astronauts James A. McDivitt (foreground) and Russell L. Schweickart at their crew stations. McDivitt is the Apollo 9 commander; and Schweickart is the lunar module pilot. At this moment Apollo 9 was orbiting Earth with the Command and Service Modules docked nose-to-nose with the Lunar Module. Astronaut David R. Scott, command module pilot, remained at the controls in the Command Module "Gumdrop" while the other two astronauts checked out the Lunar Module. McDivitt and Schweickart moved into the Lunar Module from the Command Module by way of the docking tunnel.

Apollo 8 astronaut Jim Lovell, left, Andrew Johnston, Vice President for Astronomy and Collections at Chicago's Adler Planetarium, center, and Ellen Stofan, Director of the Smithsonian's National Air and Space Museum, right, look at Lovell's Apollo 8 flight plan during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo astronaut Alan Bean, center, laughs at a comment made by Apollo astronaut Charles Duke, right, as Apollo astronaut Buzz Aldrin, left, looks on during a live television interview on Monday, July 20, 2009, at NASA Headquarters in Washington. Monday marked the 40th Anniversary of the historic landing of Apollo 11 on the Moon. Photo Credit: (NASA/Paul E. Alers)

Apollo 11 astronaut Buzz Aldrin, the second man to walk on the Moon, seated left, responds to a question during a live television interview on Monday, July 20, 2009, at NASA Headquarters in Washington as Apollo 12 astronaut Alan Bean and Apollo 16 astronaut Charles Duke, right look on. The three sat in for interviews with morning talks shows covering the 40th Anniversary of the Apollo 11 landing on the Moon. Photo Credit: (NASA/Paul E. Alers)

Apollo 8 astronaut Jim Lovell shakes hands with NASA Administrator Jim Bridenstine after being introduced during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell speaks during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell is seen during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell speaks during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell speaks during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell speaks during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Ellen Stofan, director of the Smithsonian's National Air and Space Museum, speaks about NASA's Apollo program during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell is seen during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell acknowledges a stating ovation after being introduced during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell speaks during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Ellen Stofan, director of the Smithsonian's National Air and Space Museum, speaks about NASA's Apollo program during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Ellen Stofan, director of the Smithsonian's National Air and Space Museum, speaks about NASA's Apollo program during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

A monitor showing a portrait of the Apollo 8 crew is seen during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell poses for a picture with his flight plan from the mission during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

Apollo 8 astronaut Jim Lovell is seen with his flight plan from the mission that was among the artifacts on display during the Smithsonian National Air and Space Museum's Spirit of Apollo event commemorating the 50th anniversary of Apollo 8, Tuesday, Dec. 11, 2018 at the Washington National Cathedral in Washington, DC. Apollo 8 was humanity's first journey to another world, taking astronauts Frank Borman, Jim Lovell, and William Anders to the Moon and back in December of 1968. Photo Credit: (NASA/Joel Kowsky)

S69-35504 (June 1969) --- The prime crews of the Apollo 10 lunar orbit mission and the Apollo 11 lunar landing mission are photographed during an Apollo 10 postflight de-briefing session. Clockwise, from left foreground, are astronauts Michael Collins, Apollo 11 command module pilot; Edwin E. Aldrin Jr., Apollo 11 lunar module pilot; Eugene A. Cernan, Apollo 10 lunar module pilot; Thomas P. Stafford, Apollo 10 commander; Neil A. Armstrong, Apollo 11 commander; and John W. Young, Apollo 10 command module pilot.

S69-35507 (June 1969) --- The prime crews of the Apollo 10 lunar orbit mission and the Apollo 11 lunar landing mission are photographed during an Apollo 10 postflight de-briefing session. Clockwise, from left, are astronauts Michael Collins, Apollo 11 command module pilot; Edwin E. Aldrin Jr., Apollo 11 lunar module pilot; Eugene A. Cernan, Apollo 10 lunar module pilot; Thomas P. Stafford, Apollo 10 commander; Neil A. Armstrong, Apollo 11 commander; and John W. Young, Apollo 10 command module pilot.

The Lunar Roving Vehicle (LRV) was designed to transport astronauts and materials on the Moon. An LRV was used on each of the last three Apollo missions; Apollo 15, Apollo 16, and Apollo 17, in 1971 and 1972, to permit the crew to travel several miles from the lunar landing site. This photograph was taken during the Apollo 16 mission.

JoAnn Morgan, retired NASA engineer, makes remarks after receiving the Pioneer Award during the Apollo 11 50th Gala on July 16, 2019. The gala, presented by Northrop Grumman, was held inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. Morgan was the first woman engineer on console at Kennedy Space Center and the only woman in the firing room during the Apollo 11 launch countdown and launch.

Stuart A. Roosa, Apollo 14 Command Module pilot, undergoes a final space suit check prior to liftoff. The Apollo 14, carrying a crew of three astronauts: Roosa; Alan B. Shepard, Jr., Mission Commander; and Edgar D. Mitchell, Lunar Module pilot, lifted off from launch complex 39A at KSC on January 31, 1971. It was the third manned lunar landing, the first manned landing in exploration of the lunar highlands, and it demonstrated pinpoint landing capability. The major goal of Apollo 14 was the scientific exploration of the Moon in the foothills of the rugged Fra Mauro region. The lunar surface extravehicular activity (EVA) of astronauts Shepard and Mitchell included setting up an automated scientific laboratory called Apollo Lunar Scientific Experiments Package (ALSEP), and collecting a total of about 95 pounds (43 kilograms) of Moon rock and soil for a geological investigation back on the Earth. Apollo 14 safely returned to Earth on February 9, 1971.

S71-37963 (July 1971) --- These three astronauts are the prime crew of the Apollo 15 lunar landing mission. They are, left to right, David R. Scott, commander; Alfred M. Worden, command module pilot; and James B. Irwin, lunar module pilot. The Apollo 15 emblem is in the background.

Personnel atop the 402-ft. Mobile Service Structure look back at the Apollo 11 spacecraft as the tower is moved away during a Countdown Demonstration Test. Photo filed 11 July 1969.

AS-205, the fifth Saturn IB launch vehicle developed by the Marshall Space Flight Center (MSFC), lifts off from Cape Canaveral, Florida on the first marned Apollo-Saturn mission, Apollo 7. Primary mission objectives included demonstration of the Apollo crew (Walter Schirra, Don Eisele, and Walter Cunningham) capabilities and the Command/Service Module rendezvous capability. In all, nine Saturn IB flights were made, ending with the Apollo-Soyuz Test Project in July 1975.

Mike Ciannilli, the Apollo, Challenger, Columbia Lessons Learned Program manager, welcomes participants to the Apollo 1 Lessons Learned presentation in the Training Auditorium at NASA’s Kennedy Space Center in Florida. The program's theme was "To There and Back Again." Guest panelists included Charlie Duke, former Apollo 16 astronaut and member of the Apollo 1 Emergency Egress Investigation Team; Ernie Reyes, retired, Apollo 1 senior operations engineer; and John Tribe, retired, Apollo 1 Reaction and Control System lead engineer. The event helped pay tribute to the Apollo 1 crew, Gus Grissom, Ed White II, and Roger Chaffee.

This is a cutaway illustration of the Apollo Spacecraft configuration and data summary.

Physicist Brian Cox serves as the moderator for a panel discussion with Apollo astronauts during the Apollo 11 50th Gala on July 16, 2019. The gala, presented by Northrop Grumman, was held inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex. From left, are Apollo 9 astronaut Rusty Schweichart, Apollo 11 astronaut Michael Collins, Apollo 16 astronaut Charlie Duke, and Apollo Flight Director Gerry Griffin.

A panel discussion with Apollo astronauts took place during the Apollo 11 50th Gala, present by Northop Grumman, inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida on July 16, 2019. From left, are Apollo 9 astronaut Rusty Schweickart, Apollo 11 astronaut Michael Collins, Apollo 16 astronaut Charlie Duke, and Apollo Flight Director Gerry Griffin.

Michael Collins; right; Apollo 11 astronaut; presents the Innovation Award to David Thompson; left; founder; president and CEO of Orbital Sciences Corp (later known as Orbital ATK); during the Apollo 50th Gala on July 16; 2019. The event; presented by Northrop Grumman; was held inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Comples in Florida. In the center at the podium is Andy Aldrin; son of Apollo 11 astronaut Buzz Aldrin.

This illustration depicts a configuration of the Soyuz spacecraft for the Apollo-Soyuz Test Project (ASTP). The ASTP was the first international docking of the U.S.'s Apollo spacecraft and the U.S.S.R.'s Soyuz spacecraft in space. For this project, the Soviets built another in their continuing series of Soyuz space capsules. The U.S. used the Saturn IB Apollo capsule. A joint engineering team from the two countries met to develop a docking system that permitted the two spacecraft to link in space and allowed the crews to travel from one spacecraft to the other.

This photograph shows an early moment of the first test flight of the Saturn V vehicle for the Apollo 4 mission, photographed by a ground tracking camera, on the morning of November 9, 1967. This mission was the first launch of the Saturn V launch vehicle. Objectives of the unmarned Apollo 4 test flight were to obtain flight information on launch vehicle and spacecraft structural integrity and compatibility, flight loads, stage separation, and subsystems operation including testing of restart of the S-IVB stage, and to evaluate the Apollo command module heat shield.

S69-34039 (18 May 1969) --- Overall view of activity in the Mission Operations Control Room in the Mission Control Center, Building 30, on the first day of the Apollo 10 lunar orbit mission. This picture was taken following CSM/LM-S-IVB separation, and prior to LM extraction from the S-IVB. The telecast from the Apollo 10's color TV camera shows the LM still attached to the S-IVB. The CSM is making the docking approach to the LM/S-IVB.

Panoramas of Apollo sites were created to familiarize various Constellation projects with the actual nature of the lunar surface. View of the Lunar Surface towards the western Horizon. Image was created using Apollo 14 images - mag 66 frames 9271 thru 9293.

David Thompson, founder, presdient and CEO of Orbital Sciences Corp. (later known as Orbital ATK), makes remarks after receiving the Innovation Award at the Apollo 50th Gala on July 16, 2019. The gala, presented by Northrop Grumman, was held inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida.

During the Apollo 11 50th Gala, presented by Northrop Grumman, on July 16, 2019, last year's space-themed constume contest winner, left, helps the announcer preent this year's winners their awards. The gala was held inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida.

David Thompson, founder, presdient and CEO of Orbital Sciences Corp. (later known as Orbital ATK), makes remarks after receiving the Innovation Award at the Apollo 50th Gala on July 16, 2019. The gala, presented by Northrop Grumman, was held inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida.

NASA Kennedy Space Center Director and retired astronaut Bob Cabana delivers remarks during the Apollo 50th Gala, presented by Northrop Grumman, inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida on July 16, 2019.

Retired NASA astronaut Charlie Precourt, vice president, propulsion systems, with Northrop Grumman, delivers remarks during the Apollo 11 50th Gala, presented by Northrop Grumman, inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex on July 16, 2019.

Al Roker, NBC TODAY Show co-host and weatherman, serves as the emcee for the Apollo 11 50th Gala, presented by Northrop Grumman, inside the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex on July 16, 2019.

AS17-152-23272 (7-19 Dec. 1972) --- The crescent Earth rises above the lunar horizon in this photograph taken from the Apollo 17 spacecraft in lunar orbit during National Aeronautics and Space Administration's (NASA) final lunar landing mission in the Apollo program. While astronauts Eugene A. Cernan, commander, and Harrison H. Schmitt, lunar module pilot, descended in the Lunar Module (LM) "Challenger" to explore the Taurus-Littrow region of the moon, astronaut Ronald E. Evans, command module pilot, remained with the Command and Service Modules (CSM) "America" in lunar orbit.

S72-50438 (September 1972) --- These three astronauts are the prime crew members of the Apollo 17 lunar landing mission. They are Eugene A. Cernan (seated), commander; Ronald E. Evans (standing on right), command module pilot; and Harrison H. Schmitt, lunar module pilot. They are photographed with a Lunar Roving Vehicle (LRV) trainer. Cernan and Schmitt will use an LRV during their exploration of the Taurus-Littrow landing site. The Apollo 17 Saturn V space vehicle is in the background. This picture was taken at Pad A, Launch Complex 39, Kennedy Space Center (KSC), Florida. The Apollo 17 insignia is in the photo insert at upper left. The insignia, designed by artist Robert T. McCall in collaboration with the crewmen, is dominated by the image of Apollo, the Greek sun god.

S69-62224 (December 1969) --- The members of the prime crew of the Apollo 13 lunar landing mission (left to right) are astronauts James A. Lovell Jr., commander; Thomas K. Mattingly II, command module pilot; and Fred W. Haise Jr., lunar module pilot. They are seated in front of a scene of the Lagoon Nebula, with the mission insignia and two items of early navigation in the foreground. Represented in the Apollo 13 emblem (center) is Apollo, the sun god of Greek mythology, symbolizing that the Apollo flights have extended the light of knowledge to all mankind. The Latin phrase Ex Luna, Scientia means "From the Moon, Knowledge." The Hindu astrolabe in Sanskrit (on right) was used to predict the position of celestial bodies before the invention of the octant (on left) was used in 1790 to determine the altitude of celestial bodies from aboard ship.

S69-32614 (April 1969) --- Astronaut Eugene A. Cernan, prime crew lunar module pilot of the Apollo 10 lunar orbit mission.