Sun. Oct 2nd, 2022

SN3 cryotest failed.

This week, SpaceX workers in South Texas loaded the third complete Starship prototype — SN3 — onto a test bench at the company’s Boca Chica launch site. On Wednesday evening, they tested the vehicle at ambient temperature with pressurized nitrogen and SN3 performed well.

On Thursday evening, SpaceX began cryotesting the vehicle, meaning it was reloaded with nitrogen, but this time it was cooled to flight-like temperatures and put under flight-like pressure. Unfortunately, just after 2 a.m. local time, SN3 failed and began to collapse on top of itself. It appeared as if the vehicle had lost pressure and was becoming top heavy.

Shortly after the failure, the founder and chief engineer of SpaceX, Elon Musk, said on Twitter“We’ll see what the data review says in the morning, but this may have been an error in the test configuration.” A test problem would be good in the sense that it means the vehicle itself performed well and the problem is easier to deal with.

This is the third time a spaceship has failed in these pilot tests that precede engine tests and possibly flight tests. Multiple sources indicated that if these preliminary tests had been successful, SN3 would have attempted a 150-meter test flight by next Tuesday.

Here’s a summary of SpaceX’s efforts to test full-scale spaceships so far:

  • spaceship Mk1: Construction began in December 2018. Failed during the pressure test in November 2019.
  • spaceship SN1: Construction began in October 2019. Failed during a pressure test on February 28.
  • spaceship SN2: Construction began in February 2020. After the failure of SN1, it was converted into a test bed for the thrust puck at the base of the missile. Passed the test on March 8 and retired.
  • spaceship SN3: Construction began in March 2020. Cryogenic test fails on April 3.
  • spaceship SN4: Construction started in March 2020. Will the test start later this month?

This failure must have been a disappointment, as the prototype rocket failed a third time before going to Raptor engine testing. And after the SN1 outage, Musk told his engineers, “In the future, you treat that rocket like it’s your baby, and you don’t send it to the test site unless you think your baby is going to be okay.”

This baby was out of order.

The reality, however, is that SpaceX is now hardware-rich and has built up a capacity in South Texas to quickly build newer and more advanced prototypes of the Starship vehicle. The probability of failure is ingrained in a privately funded program that builds, tests, fails, learns, and then restarts the cycle. So Musk and his engineers will learn from this failure and will likely begin testing SN4 later this month.

List image by Trevor Mahlmann for Ars

By akfire1

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