Inside the rockets that NASA and SpaceX plan to send to the moon



As the United States returns its attention to the possibilities of human spaceflight beyond low Earth orbit – back to the moon, possibly on to Mars – two very large rockets, one from NASA and one from SpaceX, are taking center stage.


In the way they are manufactured, the way they’re financed and the way they’re supposed to work, these two ships represent starkly differing approaches to getting off the Earth.



The SLS will use mainly tried-and-true NASA hardware — some of it actually left over from the Apollo era of the 1960s and 70s — to boost the Orion spacecraft into orbit around the moon.


As with all NASA rockets before it, the SLS rocket stages are expended and then splashed into the ocean, never to be recovered.

The approach was dictated by Congress: NASA already had the equipment for it. They’d seen it work. Going back to it seemed the budget-conscious choice.

Once the spacecraft clears most of the atmosphere, the Launch Abort System fairings and tower that surround Orion are jettisoned, falling back to earth.


Orion, while superficially similar to the old Apollo capsules, has new technology to accommodate longer missions, more people and better communications.



In both appearance and functionality, Starship, from Elon Musk’s venture SpaceX, is a sharp contrast to NASA’s tried-and-true approach.

While the SLS rockets are for one-time use, many of the main components of the Super Heavy Boosters will land and be reused on subsequent flights.


The Super Heavy Booster will loft Starship: A next-generation spacecraft intended to rendezvous with NASA’s Orion spacecraft and take its astronauts to the surface of the moon.


The divergent approaches to space travel between NASA and SpaceX can be seen down to the engines powering the rockets.

At the heart of the SLS is the RS-25 rocket engine.

Not just a version of the engines that launched space shuttles into orbit for 30 years, but in fact the very same engines. Those that survived have been updated and refurbished. Designed to be reusable, they’ll go on a one-way mission this time.


SpaceX’s Raptor rocket engine, on the other hand, is an entirely new design and conceived to be reusable with a minimum of maintenance and refurbishment between flights.


But perhaps the biggest innovation of the Raptor engines is how SpaceX plans to use them.

NASA’s SLS blasts off with four heavy duty engines out for one last ride. But SpaceX’s Heavy Booster will lift from the pad using 33 engines firing at once. They’re lower powered and designed to be nimble, versatile and operable across projects.



Now that NASA has successfully completed the first flight of the SLS and Orion, a mission known as Artemis I, NASA is looking to put a crew of as many as four astronauts on Orion for a flight around the moon. That Artemis II mission could come as soon as 2024, with a landing on the lunar surface planned for a year or two later.

SpaceX’s Starship could also soon hit a major milestone, with the first launch attempt to reach orbit expected later this year.

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The New Space Age
As humanity looks once again to the heavens, this series examines the recent boom of the private space industry, the long-term ambitions of NASA and foreign space agencies, and the potentially profound implications of this moment for society.
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About this story

Additional design and development by Betty Chavarria. Editing by Kate Rabinowitz, Manuel Canales and Jeff Dooley. Copy editing by Wayne Lockwood and Liz McGehee.