SpaceX loses another Starship prototype as landing sequence fails

Despite a thickly fogged launch site in South Texas, SpaceX let its SN11 Starship prototype fly on Tuesday morning at 8 am local time.

An onboard camera showed the vehicle making a nominal ascent to about 10 km, shutting off its three Raptor rocket engines in turn. As the vehicle ascended, it cleared the low cloud deck into blue skies. Starship then hovered before beginning its return to Earth.

The camera attached to the Starship vehicle's exterior provided imagery during the descent, which appeared to be fairly smooth as the vehicle "flopped" over and oriented itself to come back through the thickening atmosphere. During three previous high-altitude flights, Starship prototypes have performed this graceful maneuver without much apparent difficulty.

With launch site cameras unable to track Tuesday's flight due to the thick sea fog, however, it was difficult to tell how well this maneuver actually went. Photographer Trevor Mahlmann, who was in South Texas to photograph the mission for Ars, realized the Texas coast was shrouded in fog, so he drove inland to where he could look back toward the coast and get a clearer view of the vehicle near its 10 km apogee.

From an inland vantage point, he was able to capture the photographs above and watch the initial belly flop maneuver. It was unlike the previous Starship flights, Mahlmann said, in that the vehicle rotated more about its axis during this initial descent. This may be an indication that something went wrong fairly early in the Starship prototype's return to Earth.

All we really know for sure is that at 5 minutes and 47 seconds into the flight, one of Starship's three Raptor engines relit to begin the final landing sequence, and then the engine-bay camera cut out in SpaceX's webcast. Contact with the vehicle was lost, at least in terms of live video pictures. Shortly after this, pieces of the Starship vehicle began raining down on the launch site, and there were reports of a series of small explosions.

In his comments on SN11's failure, SpaceX founder Elon Musk did not reference any issues related to the belly flop maneuver:

Looks like engine 2 had issues on ascent & didn’t reach operating chamber pressure during landing burn, but, in theory, it wasn’t needed.

Something significant happened shortly after landing burn start. Should know what it was once we can examine the bits later today.

— Elon Musk (@elonmusk) March 30, 2021

It is not clear whether the vehicle's flight termination system was activated to destroy the Starship before it veered off course. However, the remnants of the vehicle landed near their intended target.

This would appear to be a setback for the Starship program, as the previous three flights had all demonstrated progress toward a successful landing. The last flight, of SN10 in early March, actually landed before exploding 10 minutes later due to fuel line breakages.

Fortunately, as part of its iterative development program, SpaceX is building a Starship vehicle at a rate of every two to three weeks. So the next prototype—likely to be SN15 as the company skips ahead toward a more advanced version—may be ready to fly in several weeks. Still, SpaceX would have liked to have gotten this one back in one piece.

Listing image by Trevor Mahlmann / Ars Technica