SpaceX's Starship Mk1 prototype encountered an explosive failure during early testing in Texas on Wednesday – you can see exactly what happened in the video below, but basically it blew its lid during cryogenic testing – a standard test that you use to see if the vehicle can hold up to extreme cold temperatures, like those it would encounter in actual use. The good news is that this is exactly why SpaceX (and anyone building rockets) does this kind of early-stage testing on the ground, in controlled, relatively safe conditions. The bad news is that this might delay the company's optimistic timelines.
— Chris B - NSF (@NASASpaceflight) November 20, 2019
As for next steps, the plan appears to be to take what Starship Mk1 has taught SpaceX so far and proceed with the next iteration of the prototype spacecraft – Starship Mk3. 'Wait, didn't we skip a Mk?' you might ask – no, because SpaceX is already building Mk2 in parallel with this now-destroyed Mk1 at its other facility in Florida.
SpaceX CEO Elon Musk was quick to answer a question on Twitter from YouTuber Everyday Astronaut regarding the next steps for Starship testing, saying it'll move on to Mk3 design, and that Mk1's value was primarily "as a manufacturing pathfinder," noting that "flight design is quite different."
This is still a different version of events and Starship development from what's been discussed previously: Starship Mk1 and Mk2 were originally characterized as high-altitude test flight vehicles, to follow the success of the 'Starhopper' snub-nosed subscale demonstrator, which was used to test a single Raptor engine for a couple of low-altitude hops at SpaceX's Texas site.
Timelines are always fluid in the space business, however, and in particular in the launch industry. SpaceX also sets incredibly optimistic timelines for most of its ambitious goals, by the open admission of both Musk and SpaceX President and COO Gwynne Shotwell. Still, the company has said it'll look to achieve orbital flight with a Starship prototype vehicle as early as next year, so we'll have to wait and see whether this inopportune test result affects that schedule.
SpaceX provided the following statement regarding today's test:
The purpose of today’s test was to pressurize systems to the max, so the outcome was not completely unexpected. There were no injuries, nor is this a serious setback.
As Elon tweeted, Mk1 served as a valuable manufacturing pathfinder but flight design is quite different. The decision had already been made to not fly this test article and the team is focused on the Mk3 builds, which are designed for orbit.