“When you look at the rocket, it looks almost retro,” said Bill Nelson, the administrator of NASA. “Looks like we’re looking back toward the Saturn V. But it’s a totally different, new, highly sophisticated–more sophisticated–rocket, and spacecraft.”
Artemis, powered by the Space Launch System rocket, is America’s first attempt to send astronauts to the moon since Apollo 17 in 1972, and technology has taken giant leaps since then. On Artemis I, the first test flight, mission managers say they are taking the SLS, with its uncrewed Orion spacecraft up top, and “stressing it beyond what it is designed for”—the better to ensure safe flights when astronauts make their first landings, currently targeted to begin with Artemis III in 2025.
But Nelson is right: The rocket is retro in many ways, borrowing heavily from the space shuttles America flew for 30 years, and from the Apollo-Saturn V.
Much of Artemis’ hardware is refurbished: Its four main engines, and parts of its two strap-on boosters, all flew before on shuttle missions. The rocket’s apricot color comes from spray-on insulation much like the foam on the shuttle’s external tank. And the large maneuvering engine in Orion’s service module is actually 40 years old—used on 19 space shuttle flights between 1984 and 1992.
“I have a name for missions that use too much new technology—failures.”
—John Casani, NASA
Perhaps more importantly, the project inherits basic engineering from half a century of spaceflight. Just look at Orion’s crew capsule—a truncated cone, somewhat larger than the Apollo Command Module but conceptually very similar.
Old, of course, does not mean bad. NASA says there is no need to reinvent things engineers got right the first time.
“There are certain fundamental aspects of deep space exploration that are really independent of money,” says Jim Geffre, Orion Vehicle Integration Manager at the Johnson Space Center in Houston. “The laws of physics haven’t changed since the 1960s. And capsule shapes happen to be really good for coming back into the atmosphere at Mach 32.”
Roger Launius, who served as NASA’s chief historian from 1990 to 2002 and as a curator at the Smithsonian Institution from then until 2017, tells of a conversation he had with John Casani, a veteran NASA engineer who managed the Voyager, Galileo and Cassini probes to the outer planets.
“I have a name for missions that use too much new technology,” he recalls Casani saying. “Failures.”
The Artemis I flight is slated for about six weeks. (Apollo 11 lasted eight days.) The ship roughly follows Apollo’s path to the moon’s vicinity, but then puts itself in what NASA calls a distant retrograde orbit. It swoops within 110 km of the lunar surface for a gravity assist, then heads 64,000 km out—taking more than a month but using less fuel than it would in closer orbits. Finally, it comes home, reentering the Earth’s atmosphere at 11 km per second, slowing itself with a heatshield and parachutes, and splashing down in the Pacific not far from San Diego.
If all four, quadruply-redundant flight computer modules fail, there is a fifth, entirely separate computer onboard, running different code to get the spacecraft home.
“That extra time in space,” says Geffre, “allows us to operate the systems, give more time in deep space, and all those things that stress it, like radiation and micrometeoroids, thermal environments.”
There are, of course, newer technolo