SpaceX’s Starhopper Flight Test Is a Big Step Forward for Elon Musk’s Moon Dreams

You know a spacecraft is cool when you watch it fly and can’t help but think it looks more like a bit of Hollywood CGI than an actual machine. The SpaceX Starhopper spacecraft was very much the real deal — a bright chrome, a 60-ft. tall, three-finned contraption powered by a single engine — when it made an exceedingly brief, 54-second flight on Aug. 27 in Boca Chica, Texas. But it still seemed whimsically imaginary.

“It almost looked like a cartoon or something,” Cheryl Stevens, a nearby resident, told Reuters.

All the same, the flight represented a tiny but very important step for the development of a much bigger spacecraft: the 180-ft. tall Starship rocket that SpaceX boss Elon Musk hopes to launch on a crewed flight around the moon as early as 2023. That’s an awfully ambitious deadline that may or may not be realistic. But the Starhopper test helped prove two critical elements of Starship hardware: the engine and the maneuvering thrusters.

NASA’s Apollo orbiter and lunar module used what are known as hypergolic fuels: a mix of hot-tempered chemicals that ignite merely by being brought into contact with each other. That eliminated the need for ignition hardware, simplifying the engine and reducing the risk of breakdowns. But hypergolics are exceedingly toxic and corrosive.

For Starship, SpaceX is introducing a new engine, named Raptor, that uses a lighter, energy-dense mix of methane and liquid oxygen. And since SpaceX envisions landing Starship upright on its fins, much the way Starhopper did, the ship needs to be nimble, “translating,” as the engineers say, left to right and forward and back while keeping its nose straight up as its crew looks for a good landing site. Starhopper validated both systems during its admittedly modest flight, rising about 500 feet into the sky and then moving 650 feet due east before settling back down to Earth.

“Congrats SpaceX team!!” Musk tweeted when the flight was done, and then, perhaps transported by a picture of the Starhopper as it was landing, surrounded by a swirl of reddish Texas dust, he added, a follow-up, with the picture: “One day Starship will land on the rusty sands of Mars.”

Maybe. For now, the new ship has a long way to go before it even makes a flight to Earth orbit — but Musk is pushing hard. There are two Starships currently under construction, one in Boca Chica and one in Cocoa, Florida, and Musk concedes he hopes that competition between the two teams of workers will serve as encouragement.

As for Starhopper, it will never fly again. It is slated instead to be used for what are known as static tests — engine firings with the vehicle itself locked in place and going nowhere. Those tests, SpaceX hopes, will help the next generation of Raptor-powered spacecraft do much more than hop.