Starship SN8 in flight
SpaceX's Starship SN8 prototype shortly after liftoff from Boca Chica, Texas, Dec. 9. Credit: SpaceX webcast

WASHINGTON — SpaceX performed the first high-altitude test flight of a prototype of its Starship launch vehicle Dec. 9, with the vehicle successfully lifting off the pad but exploding when attempting a landing several minutes later.

The Starship SN8 vehicle lifted off from SpaceX’s test site at Boca Chica, Texas, at approximately 5:45 p.m. Eastern. The flight was the first high-altitude test of the vehicle, intended to go to an altitude of 12.5 kilometers before descending and making a powered vertical landing back at the launch site.

The vehicle ascended into the Texas sky, although SpaceX did not immediately provide information on the actual altitude that the vehicle reached. One of the three Raptor engines in the base of the vehicle shut down 1 minute and 40 seconds after liftoff, briefly igniting equipment in the engine bay. A second engine shut down 3 minutes and 15 seconds after liftoff.

The last engine shut down 4 minutes and 40 seconds after liftoff, at which point the vehicle began to descend. It shifted into a horizontal orientation, using its fins to guide its descent. At 6 minutes and 32 seconds after liftoff, Starship reignited its engines and reoriented to the vertical to attempt a powered landing. However, the vehicle appeared to be going too fast and made a hard landing 10 seconds later, exploding.

SN8 upon landing
The Starship SN8 prototype explodes upon landing. Credit: SpaceX webcast

That explosion destroyed the vehicle, leaving behind a large portion of the nose cone section but little else. Nonetheless, SpaceX declared the flight a success on its webcast, displaying a graphic stating, “Awesome test. Congrats Starship team!”

“Fuel header tank pressure was low during landing burn, causing touchdown velocity to be high & RUD, but we got all the data we needed!” Musk tweeted shortly after the flight. A “RUD” is a “rapid unscheduled disassembly,” or an explosion. “Congrats SpaceX team hell yeah!!”

Fuel header tank pressure was low during landing burn, causing touchdown velocity to be high & RUD, but we got all the data we needed! Congrats SpaceX team hell yeah!!

— Elon Musk (@elonmusk) December 9, 2020

Musk had played down the chances of a completely successful test flight before the SN8 liftoff. “Probably 1/3 chance of completing all mission objectives,” he tweeted Dec. 7, the day before the first launch attempt for Starship SN8. SpaceX scrubbed that Dec. 8 launch attempt just 1.3 seconds before liftoff after an “auto abort” of the Raptor engines.

The SN8 vehicle is the latest in a line of prototypes developed by SpaceX for its next-generation reusable launch system. Two previous vehicles, SN5 and SN6, each made brief “hop” flights in August and September, respectively, going to no more than 150 meters before landing on flights lasting about one minutes each. Those prototypes, which lacked the nose cone sections and aerodynamic surfaces needed for high-altitude flights, were retired after their hop tests.

Four other prototypes were destroyed in earlier ground tests, dating back to November 2019. Three were destroyed in pressurization tests while a fourth, SN4, exploded after what appeared to be a successful static-fire test in May.

Those failures have put SpaceX behind the schedule Musk set at a media event in Boca Chica in September 2019. “This thing is going to take off, fly to 65,000 feet, about 20 kilometers, and come back and land, in about one or two months,” he said then, referring to a prototype called Starship Mark 1 on display then. That prototype was destroyed in a November 2019 pressurization test.

Despite the test failures and delays, SpaceX has continued to produce more prototypes as it expands its production facility at Boca Chica, on the coast of the Gulf of Mexico near Brownsville, Texas. Another Starship prototype, SN9, is largely complete, and could begin testing in the near future.

“Mars, here we come!!” Musk tweeted after the SN8 flight.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...