Astronauts Thomas K. Mattingly, II., right, and Henry Hartsfield, Jr. pose for news photographers in front of the Space Shuttle vehicle during break in the countdown demonstration test (CDDT) for STS-4.

Apollo XI Launch Vehicle AS-506 and Spacecraft 107, Launch Pad 39A for CDDT (Countdown Demonstration Test), includes MSS (Mobile Service Structure) pullback, KSC. 1. APOLLO XI - PRELAUNCH KENNEDY SPACE CENTER, FL

S69-56596 (28 Oct. 1969) --- A nighttime, ground-level view of Pad A, Launch Complex 39, Kennedy Space Center (KSC) showing the Apollo 12 (Spacecraft 108/Lunar Module 6/Saturn 507) space vehicle, during the terminal phase of a Countdown Demonstration Test (CDDT). The crew of the National Aeronautics and Space Administration's (NASA) second lunar landing mission will be astronauts Charles Conrad Jr., commander; Richard F. Gordon Jr., command module pilot; and Alan L. Bean, lunar module pilot. The Apollo 12 launch has been scheduled for 11:22 a.m. (EST) on Nov. 14, 1969.

S73-25696 (15 May 1973) --- An overall view of Pad B, Launch Complex 39, Kennedy Space Center, Florida, showing the Skylab 2/Saturn 1B space vehicle during a Countdown Demonstration Test (CDDT). This is the launch vehicle for the first manned Skylab mission. The vapor being emitted from the vehicle is the venting of cryogenic propellants. Photo credit: NASA

S69-33853 (4 May 1969) --- Ground-level view of the Apollo 10 (Spacecraft 106/Lunar Module 4/Saturn 505) space vehicle on Pad B, Launch Complex 39, Kennedy Space Center, Florida. This photograph of the 363-feet tall Apollo/Saturn V stack was taken during Countdown Demonstration Test (CDDT) activity. The Apollo 10 crew will be astronauts Thomas P. Stafford, commander; John W. Young, command module pilot; and Eugene A. Cernan, lunar module pilot.

KENNEDY SPACE CENTER, FLA. -- A technician helps astronaut Thomas P. Stafford, Apollo 10 commander, suit up for the Countdown Demonstration Test (CDDT) which ended successfully at 1:01 p.m. today. The CDDT is a dress rehearsal for the launch of Apollo 10 from Pad B at Launch Complex 39 May 18 at 12:49 p.m.

Crew depart the Neil A. Armstrong Operations and Checkout Building to travel to the Vehicle Assembly Building to board their Orion spacecraft atop NASA’s SLS (Space Launch System) rocket as part of the Artemis II Countdown Demonstration Test, December 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Charlie Blackwell-Thompson, Artemis launch director, and Jeremy Graeber, assistant launch director, monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Charlie Blackwell-Thompson, Artemis launch director, talks to Wes Mondale, NASA test director, during a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Charlie Blackwell-Thompson, Artemis launch director, and Jeremy Graeber, assistant launch director, monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Jeremy Graeber, assistant launch director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Wes Mosedale, NASA test director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Teams monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Charlie Blackwell-Thompson, Artemis launch director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Teams monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Teams monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Dan Florez, NASA test director (second from right), monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Jeremy Graeber, assistant launch director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Jeremy Graeber, assistant launch director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

From left, Jeff Spaulding, senior NASA test director, and Wes Mosedale, NASA test director, monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Charlie Blackwell-Thompson, Artemis launch director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Dan Florez, NASA test director (second from right), monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Jeremy Graeber, assistant launch director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Charlie Blackwell-Thompson, Artemis launch director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Teams monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Teams monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Charlie Blackwell-Thompson, Artemis launch director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Teams monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Teams monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Charlie Blackwell-Thompson, Artemis launch director, monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Randy Bresnick monitors the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Teams monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

Teams monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

From right, Shawn Quinn NASA’s Exploration Ground Systems program manager; Cliff Lanham, NASA’s Exploration Ground Systems deputy program manager; and Howard Hu, Orion program manager, monitor the progress of a countdown demonstration test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 1 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

S72-34473 (29 March 1972) --- A ground-level view of Pad A, Launch Complex 39, Kennedy Space Center (KSC), showing the 363-feet tall Apollo 16 (Spacecraft 113/Lunar Module 11/Saturn 511) space vehicle during a Countdown Demonstration Test (CDDT). The CDDT was part of the preflight preparations for the Apollo 16 lunar landing mission. The crew of Apollo 16, scheduled for launch on April 16, 1972, are astronauts John W. Young, commander; Thomas K. (Ken) Mattingly II, command module pilot; and Charles M. Duke Jr., lunar module pilot.

KENNEDY SPACE CENTER, FLA. - Technicians make the final adjustments to Apollo 11 Commander Neil A. Armstrong's spacesuit as he prepares to take part in a space vehicle Countdown Demonstration Test (CDDT). Astronauts Armstrong, Aldrin and Collins are practicing for ther mission, the first manned Lunar landing.

The Apollo 17 prime crew leaves the Manned Spaceflight Operations Building to enter the transfer van which will carry them to Complex 39's Pad A to participate in the CDDT. From right are Eugene A. Cernan, Commander Ronald E. Evans, Command Module Pilot, and Harrison H. Schmitt, Lunar Module Pilot.

From left, NASA astronauts Reid Wiseman, Artemis II commander, Victor Glover, Artemis II pilot, Christina Koch, Artemis II mission specialist and CSA (Canadian Space Agency) astronaut Jeremy Hansen, Artemis II mission specialist, depart the Neil A. Armstrong Operations and Checkout Building to travel to the Vehicle Assembly Building to board their Orion spacecraft atop NASA’s SLS (Space Launch System) rocket as part of the Artemis II Countdown Demonstration Test on Saturday, Dec. 20, 2025 at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut, Christina Koch, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

From left, NASA astronauts Victor Glover, Artemis II pilot, and Reid Wiseman, Artemis II commander, undergo spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

CSA (Canadian Space Agency) astronaut Jeremy Hansen, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Victor Glover, Artemis II pilot, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Reid Wiseman, Artemis II commander, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut, Christina Koch, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronauts Reid Wiseman, Artemis II commander, Victor Glover, Artemis II pilot, Christina Koch, Artemis II mission specialist and CSA (Canadian Space Agency) astronaut Jeremy Hansen, Artemis II mission specialist, depart the Neil A. Armstrong Operations and Checkout Building to travel to the Vehicle Assembly Building to board their Orion spacecraft atop NASA’s SLS (Space Launch System) rocket as part of the Artemis II Countdown Demonstration Test on Saturday, Dec. 20, 2025 at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

CSA (Canadian Space Agency) astronaut Jeremy Hansen, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Victor Glover, Artemis II pilot, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

From left, NASA astronauts Reid Wiseman, Artemis II commander, Christina Koch, Artemis II mission specialist, CSA (Canadian Space Agency) astronaut Jeremy Hansen, Artemis II mission specialist, and NASA astronaut Victor Glover, Artemis II pilot, depart the Neil A. Armstrong Operations and Checkout Building to travel to the Vehicle Assembly Building to board their Orion spacecraft atop NASA’s SLS (Space Launch System) rocket as part of the Artemis II Countdown Demonstration Test on Saturday, Dec. 20, 2025 at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut, Christina Koch, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Reid Wiseman, Artemis II commander, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

CSA (Canadian Space Agency) astronaut Jeremy Hansen, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut, Christina Koch, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Reid Wiseman, Artemis II commander, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut, Christina Koch, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

CSA (Canadian Space Agency) astronaut Jeremy Hansen, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut, Christina Koch, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Reid Wiseman, Artemis II commander, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Victor Glover, Artemis II pilot, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut, Christina Koch, Artemis II mission specialist, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

From left, NASA astronauts Victor Glover, Artemis II pilot, and Reid Wiseman, Artemis II commander, undergo spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

From left, NASA astronauts Victor Glover, Artemis II pilot, and Reid Wiseman, Artemis II commander, undergo spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Victor Glover, Artemis II pilot, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

NASA astronaut Victor Glover, Artemis II pilot, undergoes spacesuit checks inside the crew quarters suit-up room in the Neil A. Armstrong Operations and Checkout Building part of the Artemis II Countdown Demonstration Test at the agency’s Kennedy Space Center on Saturday, Dec. 20, 2025. For this operation, the Artemis II crew and launch team are simulating the launch day timeline including suit-up, walkout, and climbing in and out of the spacecraft. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all.

S75-28387 (2 July 1975) --- A nighttime view of Pad B, Launch Complex 39, Kennedy Space Center, showing the ASTP Apollo/Saturn 1B space vehicle on the pad during Apollo-Soyuz Test Project prelaunch preparations. An ASTP countdown demonstration ?wet? test (CDDT) was being conducted at KSC when this photograph was taken. The liftoff was on July 15, 1975.

S82-28456 (19 Feb. 1982) --- Astronauts Jack R. Lousma, left, STS-3 commander, and C. Gordon Fullerton, pilot, are briefed on emergency procedures at Launch Pad 39A by Buck Tomlinson, a safety instructor with Wackenhut Services, Inc. Also pictured is astronaut Daniel C. Brandenstein, STS-8 pilot. The men were at Kennedy Space Center (KSC) for participation in a countdown demonstration test (CDDT). Photo credit: NASA

S82-28454 (19 Feb. 1982) --- Astronaut Jack R. Lousma, right, STS-3 commander, and C. Gordon Fullerton, pilot, carry portable spacesuit air controllers as they walk from a transport van to Launch Pad 39A to participate in a simulated countdown and launch. This countdown demonstration test (CDDT) is part of the preparations for NASA?s third orbital flight test in the space shuttle Columbia. The two are scheduled to spend a week orbiting Earth in Columbia this spring. Photo credit: NASA

S69-25488 (23 Feb. 1969) --- Interior view of the White Room at Pad A, Launch Complex 39, Kennedy Space Center (KSC), during an Apollo 9 Countdown Demonstration Test (CDDT). Astronauts James A. McDivitt, commander; David R. Scott, command module pilot; and Russell L. Schweickart, lunar module pilot, were participating in a dress rehearsal in preparation for their scheduled 10-day Earth-orbital space mission.

S75-28386 (2 July 1975) --- An early morning view of Pad B, Launch Complex 39, Kennedy Space Center, showing the ASTP Apollo/Saturn 1B space vehicle on the pad during Apollo-Soyuz Test Project prelaunch preparations. An ASTP countdown demonstration "wet" test (CDDT) was being conducted at KSC when this photograph was taken. The liftoff was on July 15, 1975.

KENNEDY SPACE CENTER, FLA. -- Astronaut John W. Young suits up for the Apollo 10 Countdown Demonstration Test (CDDT) which ended successfully at 1:01 p.m. today, clearing the way for a May 18 launch. Young, command module pilot, will keep lonely vigil in lunar orbit while Thomas P. Stafford, commander, and Eugene A. Cernan, lunar module pilot, drop to within 10 miles of the Moon in the lunar module before returning to the parent spacecraft.

S81-38547 (10 Sept. 1981) --- Astronauts Joe H. Engle, right, and Richard H. Truly, prime crew members for STS-2, complete their suiting up chores prior to a countdown demonstration test (CDDT). They are in the operations and checkout building at the Kennedy Space Center. The two have a launch scheduled for late autumn of this year. Photo credit: NASA

S93-45004 (20 Sept 1993) --- Posing for a crew portrait, with the Space Shuttle Columbia at Launch Pad 39B, are the seven STS-58 astronauts. They are, front row left to right, John E. Blaha, mission commander; Martin J. Fettman, payload specialist; and David A. Wolf, mission specialist. Back row, left to right, are Richard A. Searfoss, pilot; William S. McArthur and Shannon W. Lucid, mission specialists; and Rhea Seddon, payload commander. The crew was in Florida for the Terminal Countdown Demonstration Test (CDDT) in preparation for next month's launch aboard Columbia.

S70-32990 (24 March 1970) --- Nighttime, ground level view of Pad A, Launch Complex 39, Kennedy Space Center (KSC), showing the Apollo 13 (Spacecraft 109/Lunar Module 7/Saturn 508) space vehicle during Countdown Demonstration Test (CDDT). The crew of NASA's third lunar landing mission includes astronauts James A. Lovell Jr., commander; John L. Swigert Jr., command module pilot; and Fred W. Haise Jr., lunar module pilot. The Apollo 13 launch has been scheduled for 2:13 p.m. (EST), April 11, 1970.

S93-45003 (20 Sept 1993) --- Posing for a crew portrait, in front of the Space Shuttle Columbia at Launch Pad 39B, are the seven STS-58 astronauts. They are, left to right, David A. Wolf, mission specialist; Martin J. Fettman, payload specialist; William S. McArthur and Shannon W. Lucid, mission specialists; John E. Blaha, mission commander; Richard A. Searfoss, pilot; and Rhea Seddon, payload commander. The crew was in Florida for the Terminal Countdown Demonstration Test (CDDT) in preparation for next month's launch aboard Columbia. (Kennedy Space Center Photo ID: KSC-93-PC-1253)

KENNEDY SPACE CENTER, FLA. - The Apollo 15 Saturn V Space Vehicle is seen from a camera located at the mobile launcher's 360-foot level at Launch Pad 39A during venting of the liquid oxygen during the 'wet' portion of the Countdown Demonstration Test today. Astronauts David R. Scott, Commander; James B. Irwin, Lunar Module Pilot; and Alfred M. Worden, Jr., Command Module Pilot, will participate tomorrow in the 'dry' portion of the Countdown Demonstration Test (CDDT), as a final dress rehearsal for the launch to the Moon, scheduled for no earlier than July 26, 1971.

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.

S82-32201 (29 May 1982) --- Members of the JSC astronaut corps, vehicle integration test team (VITT) and other personnel pose for a photograph at the completion of a countdown demonstration test (CDDT) at Launch Pad 39A, Kennedy Space Center (KSC). The participants are, from the left, Wilbur J. Etbauer, engineer with the VITT; mission specialist-astronaut James D. Van Hoften; Terri Stanford, engineer from JSC's flight operations directorate; mission specialist-astronaut Steven A. Hawley; astronaut Richard N. Richards; astronaut Michael J. Smith; Richard W. Nygren, head of the VITT; mission specialist-astronaut Kathryn D. Sullivan; astronaut Henry W. Hartsfield Jr., STS-4 pilot; Mark Haynes, a co-op student participating with the VITT; astronaut Thomas K. Mattingly II, STS-4 commander; and astronaut Donald E. Williams. Photo credit: NASA

S82-32200 (29 May 1982) --- Members of the JSC astronaut corps, STS-4 vehicle integration test team (VITT) and other personnel pose for a photograph at the completion of a countdown demonstration test (CDDT) at Launch Pad 39A, Kennedy Space Center (KSC). The participants are, from the left, Wilbur J. Etbauer, engineer with the VITT; mission specialist-astronaut James D. van Hoften; Terry Stanford, engineer from JSC's flight operations directorate; mission specialist-astronaut Steven A. Hawley; astronaut Richard N. Richards; astronaut Michael J. Smith; Richard W. Nygren, head of the VITT; mission specialist-astronaut Kathryn D. Sullivan; astronaut Henry W. Hartsfield Jr.,STS-4 pilot; Mary Haynes, a co-op student participating with the VITT; astronaut Thomas K. Mattingly II, STS-4 commander; and astronaut Donald E. Williams. Photo credit: NASA

S69-34333 (13 May 1969) --- The three Apollo 10 astronauts suit up for a Countdown Demonstration Test at the Kennedy Space Center during preparations for their scheduled lunar orbit mission. From front to rear, are Thomas P. Stafford, commander; John W. Young, command module pilot; and Eugene A. Cernan, lunar module pilot.

S69-34330 (13 May 1969) --- Astronaut Thomas P. Stafford, Apollo 9 commander, is suited up at the Kennedy Space Center for a Countdown Demonstration Test during preparations for the scheduled Apollo 10 lunar orbit mission. The other two crewmembers are astronauts John W. Young, command module pilot; and Eugene A. Cernan, lunar module pilot.

S82-28457 (19 Feb. 1982) --- Member of the JSC astronaut corps., STS-3 vehicle integration test (VIT) team and other personnel pose for a photograph at the completion of a countdown demonstration test (CDDT) and safety briefings at Launch Pad 39A, Kennedy Space Center (KSC). Participants are, from the left, Wilbur J. Etbauer, engineer with the VIT team; George W. S. Abbey, director of flight operations at JSC; astronaut John W. Young, chief of the astronaut office at JSC; Jack Fleming of Rockwell International; mission specialist-astronaut John M. Lounge; astronaut Daniel C. Brandenstein; mission specialist-astronaut James D. Van Hoften; astronauts C. Gordon Fullerton and Jack Lousma, prime crew for STS-3; Olan J. Bertrand, VIT team member; mission specialist-astronaut Kathryn D. Sullivan; Richard W. Nygren, head of the VIT team; and astronaut Donald E. Williams. The space shuttle Columbia is obscured by its service structure on Launch Pad 39A in the background. Part of slide-wire type emergency escape system is visible in the picture. Photo credit: NASA

CAPE CANAVERAL, Fla. – ASTP prime crewmen Donald Slayton, Thomas Stafford and Vance Brand pose with their Saturn IB launch vehicle following the Countdown Demonstration Test [CDDT], a step-by-step dress rehearsal for their July 15 launch. During the “wet” portion of the test, conducted yesterday, the stages of the launch vehicle were fueled as they will be on launch day. The fuels were off loaded and the terminal portion of the count repeated today with the astronauts aboard the vehicle. The first international crewed spaceflight was a joint U.S.-U.S.S.R. rendezvous and docking mission. The Apollo-Soyuz Test Project, or ASTP, took its name from the spacecraft employed: the American Apollo and the Soviet Soyuz. The three-man Apollo crew lifted off from Kennedy Space Center aboard a Saturn IB rocket on July 15, 1975, to link up with the Soyuz that had launched a few hours earlier. A cylindrical docking module served as an airlock between the two spacecraft for transfer of the crew members. Photo credit: NASA

The sun sets as Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist participate in the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The astronaut transport vehicle carrying Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist is seen as it approaches the Vehicle Assembly Building during the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The sun rises shortly before Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist participate in the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The astronaut transport vehicle carrying Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist is seen as it departs the Vehicle Assembly Building following the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams simulated the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The sun rises shortly before Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist participate in the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The astronaut transport vehicle carrying Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist is seen as it departs the Vehicle Assembly Building following the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams simulated the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The astronaut transport vehicle carrying Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist is seen as it departs the Vehicle Assembly Building following the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams simulated the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The astronaut transport vehicle carrying Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist is seen as it approaches the Vehicle Assembly Building during the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The astronaut transport vehicle carrying Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist is seen as it approaches the Vehicle Assembly Building during the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The sun rises shortly before Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist participate in the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Keegan Barber)

The elevator button for the 275-foot level of the mobile launcher is seen teams prepare for Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist; to arrive and board their Orion spacecraft atop NASA’s Space Launch System rocket during the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Joel Kowsky)

Will Sattler of the Closeout Crew is seen on the crew access arm just outside of the white room awaiting the arrival of Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist; at the 275-foot level of the mobile launcher as they prepare to board their Orion spacecraft atop NASA’s Space Launch System rocket during the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Joel Kowsky)

Artemis II crewmember NASA astronaut Christina Koch, mission specialist, is seen inside the white room at the 275-foot level of the mobile launcher she and fellow crewmates NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist, prepare to board their Orion spacecraft atop NASA’s Space Launch System rocket during the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Joel Kowsky)

Teams monitor the progress of a Countdown Demonstration Test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 2 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Aubrey Gemignani)

Teams monitor the progress of a Countdown Demonstration Test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 2 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Aubrey Gemignani)

Emily Nelson, NASA's chief flight director, Lori Glaze, acting associate administrator for NASA's Exploration Systems Development Mission Directorate, and Stephanie Schierholz, chief of staff for NASA's Exploration Systems Development Mission Directorate, discuss the progress of a Countdown Demonstration Test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 2 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Aubrey Gemignani)

Left to right, Adam Steltzner, engineering advisor to the NASA Associate Administrator, Emily Nelson, NASA's chief flight director, and Lori Glaze, acting associate administrator for NASA's Exploration Systems Development Mission Directorate, discuss the progress of a Countdown Demonstration Test with Artemis II crewmembers NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist onboard their Orion spacecraft from Firing Room 2 of the Rocco A. Petrone Launch Control Center, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Aubrey Gemignani)

CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist is seen as he can his crew mates NASA astronauts Reid Wiseman, commander (not pictured); Victor Glover, pilot; and Christina Koch, mission specialist depart the Neil A. Armstrong Operations and Checkout Building to board their Orion spacecraft atop NASA’s Space Launch System rocket inside the Vehicle Assembly Building as part of the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Aubrey Gemignani)

NASA astronaut Reid Wiseman, commander is seen as he and crew mates Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist, not pictured, are seen as they depart the Neil A. Armstrong Operations and Checkout Building to board their Orion spacecraft atop NASA’s Space Launch System rocket inside the Vehicle Assembly Building as part of the Artemis II countdown demonstration test, Saturday, Dec. 20, 2025, at NASA’s Kennedy Space Center in Florida. For this operation, the Artemis II crew and launch teams are simulating the launch day timeline including suit-up, walkout, and spacecraft ingress and egress. Through the Artemis campaign, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and to build the foundation for the first crewed missions to Mars, for the benefit of all. Photo Credit: (NASA/Aubrey Gemignani)