For the first time in half a century, NASA is preparing to launch a moon rocket. After multiple delays and redesigns, the giant Artemis 1 vehicle has rolled to the launch pad for the first in a series of final rehearsals for an unmanned Orion spacecraft mission around the moon. The combination of the Space Launch System and Orion spacecraft has been in development since the end of the space shuttle program and shares several key technologies with the earlier vehicle, including main engines, airframe structures and segmented solid rocket boosters.The use of proven design elements in the Artemis program is hoped to grant the system capabilities that exceed the Apollo program’s Saturn 5 launch vehicle, with better reliability and lower relative costs. And there is another similarity to the 1960s: a space race. The race today is with Elon Musk’s SpaceX, whose giant Starship is already on the launch pad undergoing tests. A firm launch date has not been set for either vehicle, although it is generally expected that Starship will likely launch first.Access all episodes of This Week in Engineering on engineering.com TV along with all of our other series.