SpaceX gearing up for 12-mile-high test flight with Starship SN8 prototype

The next big leap for SpaceX's Mars-colonizing Starship spacecraft appears to be right around the corner.

Two full-size Starship prototypes, known as SN5 and SN6, recently performed 500-foot-high (150 meters) test hops at SpaceX's South Texas facilities, near the village of Boca Chica. And the next vehicle in line is nearly ready to soar much higher, company founder and CEO Elon Musk said.

"SN8 Starship with flaps & nosecone should be done in about a week. Then static fire, checkouts, static fire, fly to 60,000 ft [18,300 m] & back," Musk said via Twitter on Saturday (Sept. 12).

 In photos: SpaceX's SN5 Starship prototype soars on 1st test flight

Static fires are routine engine tests conducted while a vehicle is tethered to the ground. The engines that will be tested in this case are SpaceX's next-generation Raptors — likely three of them, to get the SN8 up so high. SN5 and SN6 sported only a single Raptor, and those vehicles didn't have nosecones or control-improving body flaps, either. (SN7 was a test tank that SpaceX intentionally burst during a pressure trial this past June, in case you were wondering.)

SpaceX is iterating toward a final version of Starship that will feature six Raptors and, Musk has said, be capable of carrying up to 100 people to the moon, Mars and other distant destinations. 

The 165-foot-tall (50 m) Starship will launch from Earth atop a gigantic rocket known as Super Heavy, which will be powered by about 30 Raptors of its own. The Starship vehicle will be powerful enough to blast itself off the moon and Mars, whose gravitational pulls are much weaker than that of our planet, Musk has said.

Both Starship and Super Heavy are designed to be fully and rapidly reusable, a technological breakthrough that SpaceX believes will make ambitious exploration feats such as Mars colonization economically feasible. 

Related: SpaceX's Starship and Super Heavy rocket in pictures

SpaceX has already booked one Starship customer — Japanese billionaire Yusaku Maezawa, who will fly around the moon on the vehicle. The target launch date for that mission is 2023. 

Starship is also in the running to land NASA astronauts on the moon, as part of the space agency's Artemis program. Artemis aims to put two astronauts down near the lunar south pole in 2024 and establish a sustainable human presence on and around the moon by the end of the decade.

Starship will fly a wide variety of missions to many different destinations, if all goes according to plan. SpaceX plans to phase out all of its other spaceflight hardware over time, handing all duties over to Starship and Super Heavy eventually.

Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.