Musk says methane leak doomed Starship’s latest test flight – Spaceflight Now

A file photo of the Starship SN8 prototype, which flew last year, with three Raptor engines. Credit: Elon Musk / SpaceX

SpaceX founder Elon Musk said Monday that a “relatively small” methane leak caused the company’s latest Starship test rocket to explode last week on an experimental flight over South Texas.

The 164-foot-tall (50-meter) Starship test vehicle, known as Series No. 11, took off from SpaceX’s development facility near Brownsville on March 30 for an atmospheric test flight at an altitude of approximately 33,000 feet. or 10,000 meters.

Three Raptor engines, each consuming supercooled methane and liquid oxygen propellants, propelled the stainless steel rocket from its launch pad with more than a million pounds of thrust.

After climbing directly above a dense layer of fog, the Starship shut down each of the Raptor engines in sequence, as planned, before launching horizontally to begin a controlled descent back to the ground. Aerodynamic flaps helped stabilize the giant rover as it fell back to Earth before the Raptor engines were supposed to re-ignite and flip the rocket upright to land on a landing pad next to the Starship launch site. .

Heavy fog prevented a clear view of what happened, but an onboard camera view on SpaceX’s live feed froze as the Raptor engines fired up to land. Other camera views showed debris falling over the test site, which Musk calls the Starbase, after a thunderous roar cracked the facility.

The spacecraft’s light debris fragments apparently traveled up to 5 miles (8 kilometers) from the launch site and landed in a public viewing area, although the material may have been dislodged from the rocket as it ascended toward the cusp of its trajectory. and not during the explosion just before landing.

Musk tweeted Monday that the climb phase of the Starship SN11 test flight proceeded according to plan. The transition to horizontal and control during its free fall back to Earth was also good, he said.

But a small methane leak caused a fire in one of the vehicle’s Raptor engines and “cold” part of an avionics system. That caused a “hard start” in the engine’s methane turbopump at the beginning of the landing combustion, Musk said.

“This is going to be fixed six says through Sunday,” Musk tweeted.

The March 30 explosion was the fourth consecutive Starship vehicle SpaceX has lost since it began high-altitude test flights in December.

A crash landing on an otherwise successful Starship test flight on December 9 was caused by low pressure from the header tanks that power the vehicle’s Raptor engines for critical combustion just prior to landing, and one of the Raptor engines failed to re-ignite for landing combustion on a February 2 test flight.

The SN10 rocket achieved the first soft landing of a full-size Starship vehicle at the end of a test flight on March 3, but the rocket exploded minutes later.

SpaceX is developing the Starship vehicle as the company’s next-generation rocket, crew, and cargo carrier to eventually replace the Falcon 9 launcher and Dragon capsule. The Starship vehicle now being tested in Texas will form the top stage of the new giant rocket, which will stand nearly 400 feet (about 120 meters) high with the Starship stacked on a massive booster stage.

The full-size rocket configured for orbital missions will have 28 Raptor engines in its first stage and six Raptor engines in Starship’s upper stage. SpaceX says it will be able to deliver more than 220,000 pounds, or 100 metric tons, of payload mass to low Earth orbit.

Once in orbit, the spacecraft will be able to receive a fresh supply of methane and liquid oxygen propellants to continue and transport its heavy cargo, and eventually people, to more distant destinations, such as the moon and Mars, according to SpaceX.

The booster stage, known as the Super Heavy, and the Starship vehicle will be fully reusable to limit launch costs.

But first SpaceX needs to master the Starship landing maneuver, which is very different from the way SpaceX lands its operational Falcon rocket boosters. SpaceX also plans to begin test flights of the first Super Heavy booster prototypes.

Starship SN11 ahead of its test flight on March 30. Credit: SpaceX

SpaceX’s next Starship rocket, designated SN15, is preparing to launch from its assembly hangar at the test site near Boca Chica Beach in South Texas. Once you’re on the launch pad, SpaceX engineers will run a series of checks and will likely attempt a refueling test and a test firing before proceeding to a test flight.

The Starship production complex is located a couple of miles inland from the launch and landing pads.

SpaceX skipped building the SN12, SN13, and SN14 in favor of an updated Starship setup that will debut with SN15.

“It has hundreds of design improvements to structures, avionics / software and engine,” Musk tweeted last week. Hopefully one of those enhancements covers this issue (with SN11). Otherwise, the modernization will add a few more days. “

SpaceX aims to launch the first fully stacked Super Heavy and Starship in an orbital launch attempt from South Texas in July. “That’s our goal,” Musk tweeted.

An orbital launch attempt for July is an aggressive target, like many programs described by the founder and CEO of SpaceX.

The next big tech upgrade to the Starship vehicle will come with the SN20 later this year, according to Musk.

“Those ships will be able to orbit with a heat shield and stage separation system,” Musk tweeted. “The probability of success in the ascent is high. However, the SN20 + vehicles will likely need many flight attempts to survive the Mach 25 input heating and land intact. “

SpaceX has stacked the first Super Heavy booster test bed, known as BN1, at the South Texas launch site. But Musk said the vehicle is a trailblazer for testing manufacturing and production techniques, and it won’t fly. Crews are building the second Super Heavy prototype, BN2, for atmospheric test flights before proceeding with the construction of BN3 for a possible orbital launch attempt.

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Follow Stephen Clark on Twitter: @ EstebanClark1.

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