SpaceX encountered a snag in an attempted test key to the development of its next-generation Starship spacecraft. Specifically, the StarHopper sub-scale demonstration and testing craft it’s using to work on the Startship’s propulsion system failed to undertake its first untethered test flight at a testing site in Boca Chica Beach in Texas.

The plan was to have the demonstration craft take off and fly to a height of 20 meters before returning to Earth, all under its own power and directed by its own guidance system. Instead, it seemed to fire rockets and then was engulfed in smoke, before venting fire out the top of the test craft for a few minutes prior to extinguishing, with StarHopper looking relatively unscathed. We’re still waiting on official confirmation from SpaceX of what happened, but they characterized this as an “abort” on a live stream of the test.

Last week during a static test fire, the StarHopper vehicle was engulfed in a large ball of flame. This wasn’t a planned event, but did not result in significant damage to the spacecraft, SpaceX later said.

StarHopper succeeded in flying its first tethered flight at the beginning of April, and has undergone further testing since then to prepare for its untethered trip. SpaceX CEO Elon Musk said earlier this month that a successful untethered test would pave the way for a full presentation of SpaceX’s Starship spacecraft plans at the end of July, but the test has encountered a few issues since then.

The reason SpaceX and other companies run tests like these is to identify potential issues early in the development process, so it’s good to see them making progress even if that doesn’t mean a “success” in the traditional sense of actually having achieved untethered flight.

The SpaceX-designed Starship will be fully reusable once complete, unlike Falcon 9 and Falcon Heavy, so it’ll reduce the cost of launches, and the company hopes to eventually use it to fly all its missions, though it’ll keep Falcon 9 and Falcon Heavy in service for its paying customers as long as there’s appetite.