Musk attributes SpaceX’s latest spaceship explosion to Raptor engine leak

CEO Elon Musk says SpaceX Starship’s last test flight ended in an in-flight explosion because a “small” leak started on one of the rocket’s three Raptor engines.

As promised, the new information offers insight into the cause of Starship SN11’s untimely demise and the challenges of iterative development of systems as complex as a fully reusable Saturn V-class launcher. On March 30, after about a week of delays, the Starship SN11 took off for SpaceX’s fourth high-altitude launch and landing test when it was almost completely obscured by a thick fog bank.

Despite the unfortunate weather conditions, which precluded almost any kind of view of the launch outside of Starship’s own cameras, the rocket performed as well as its three predecessors, reaching an expected peak of 10 km (6.2 mi) before launch. free fall of the belly. first return to earth. At T + 5: 49, however, things took a turn for the worse.

The ascent phase, the transition to horizontal and the control during the free fall were good.

A (relatively) small CH4 leak caused a fire on engine 2 and a fried portion of the avionics, causing a difficult start during an attempted landing burn in a CH4 turbopump.

This is corrected in 6 ways until Sunday.

– Elon Musk (@elonmusk) April 5, 2021

At this point, Starship attempted to ignite its three Raptor engines to switch to a rear landing configuration, at which point two of those engines would be shut down, leaving the healthier of the three to attempt a soft landing. Something immediately went wrong and telemetry, live video and countdown froze in sight of a partially ignited Raptor engine.

Notably, as shown in the image at the top of this article, it is possible that the “small [methane] Leak ”Musk blamed that the SN11 failure was visible on the Raptor SN52 engine within 30 seconds of Starship’s takeoff, leaving enough time for a high pressure fire to seriously damage the failed engine and its adjacent partners. SpaceX CEO says the resulting fire “fried some of [the] avionics “controlling one or all three Raptors,” causing [a] difficult start ”which damaged or destroyed one or all of the engines when they attempted to begin their landing.

Based on analysis of unofficial videos taken by cameras near the Starship launch site, it was deemed likely that SN11 exploded not because its Flight Termination System (FTS) tripped. – but because of Raptor’s violent and explosive “hard start”. Ultimately, it’s not clear whether SpaceX itself will ever be able to paint a really clear picture of what exactly happened to SN11, but Musk says the suspicious Raptor leak “is about to happen.” corrected [six] until Sunday. It’s possible that a Musk upgraded Raptor engine making its Starship SN15 debut has already fully or partially addressed what caused the SN11’s engine leakage and rough starts.

Either way, SN15 is expected to roll off the launch pad already as early as this week – just days after the SN11 explosion – and SpaceX won’t have to wait long to test the fixes it implements. as the upgraded vehicle operates towards static fire tests and its own. launch its debut.