Dr. von Braun and Don Ostrander, head of the Launch Vehicle Program of the NASA Headquarters look at a model of the Saturn I launch complex 34.

The test of twin Linear Aerospike XRS-2200 engines, originally built for the X-33 program, was performed on August 6, 2001 at NASA's Sternis Space Center, Mississippi. The engines were fired for the planned 90 seconds and reached a planned maximum power of 85 percent. NASA's Second Generation Reusable Launch Vehicle Program , also known as the Space Launch Initiative (SLI), is making advances in propulsion technology with this third and final successful engine hot fire, designed to test electro-mechanical actuators. Information learned from this hot fire test series about new electro-mechanical actuator technology, which controls the flow of propellants in rocket engines, could provide key advancements for the propulsion systems for future spacecraft. The Second Generation Reusable Launch Vehicle Program, led by NASA's Marshall Space Flight Center in Huntsville, Alabama, is a technology development program designed to increase safety and reliability while reducing costs for space travel. The X-33 program was cancelled in March 2001.

The Vehicle Assembly Building is seen at sunset as preparations continue for the NASA’s SpaceX Demo-2 mission, Monday, May 25, 2020, at NASA’s Kennedy Space Center in Florida. NASA’s SpaceX Demo-2 mission is the first launch with astronauts of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the International Space Station as part of the agency’s Commercial Crew Program. The test flight serves as an end-to-end demonstration of SpaceX’s crew transportation system. Robert Behnken and Douglas Hurley are scheduled to launch at 4:33 p.m. EDT on Wednesday, May 27, from Launch Complex 39A at the Kennedy Space Center. A new era of human spaceflight is set to begin as American astronauts once again launch on an American rocket from American soil to low-Earth orbit for the first time since the conclusion of the Space Shuttle Program in 2011. Photo Credit: (NASA/Joel Kowsky)

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

These images and video show NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

These images and video show NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows NASA’s SLS (Space Launch System) and Orion spacecraft rolling out of the Vehicle Assembly Building at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carries the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

Boeing’s CST-100 Starliner spacecraft passes by the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida on Nov. 21, 2019, making its way to the Space Launch Complex 41 Vertical Integration Facility at Cape Canaveral Air Force Station. At the pad, Starliner will be secured atop a United Launch Alliance Atlas V rocket in preparation for Boeing’s uncrewed Orbital Flight Test to the International Space Station for NASA’s Commercial Crew Program.

Boeing’s CST-100 Starliner spacecraft passes by the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida on Nov. 21, 2019, making its way to the Space Launch Complex 41 Vertical Integration Facility at Cape Canaveral Air Force Station. At the pad, Starliner will be secured atop a United Launch Alliance Atlas V rocket in preparation for Boeing’s uncrewed Orbital Flight Test to the International Space Station for NASA’s Commercial Crew Program.

Boeing’s CST-100 Starliner spacecraft passes by the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida on Nov. 21, 2019, making its way to the Space Launch Complex 41 Vertical Integration Facility at Cape Canaveral Air Force Station. At the pad, Starliner will be secured atop a United Launch Alliance Atlas V rocket in preparation for Boeing’s uncrewed Orbital Flight Test to the International Space Station for NASA’s Commercial Crew Program.

S73-25140 (16 April 1973) --- A ground-level view of Pad A, Launch Complex 39, Kennedy Space Center, Florida, showing the 341-feet tall Skylab 1/Saturn V space vehicle on the pad soon after being rolled out from the Vehicle Assembly Building (VAB). The vehicle is composed of the Saturn V first (S-1C) stage, the Apollo Telescope Mount (ATM), the Multiple Docking Adapter (MDA), the Airlock Module (AM), and the Orbital Workshop (OWS). Photo credit: NASA

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

This image shows a sunset of NASA’s SLS (Space Launch System) and Orion spacecraft at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carried the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows a sunset of NASA’s SLS (Space Launch System) and Orion spacecraft at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carried the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.

This image shows a sunset of NASA’s SLS (Space Launch System) and Orion spacecraft at NASA’s Kennedy Space Center. NASA's massive Crawler-Transporter, upgraded for the Artemis program, carried the powerful SLS rocket and Orion spacecraft on the Mobile Launcher from the Vehicle Assembly Building to Launch Pad 39B at Kennedy Space Center in preparation for the Artemis II mission.