The current version of Starship, which SpaceX debuted in January, has hit one signficant setback after another.
The vehicle made it farther in its flight path during a mission in May — but ultimately spun out of control before landing.
Then, in June, a Starship spacecraft exploded during a routine engine test.
After each ill-fated trial, SpaceX has said it investigated the issue and implemented changes to the vehicle’s hardware and flight profile in the hopes of getting better results.
In a technical brief posted to its website last week, SpaceX said it believes that Starship began tumbling out of control during its last test flight in May because of abnormally high pressure that built up in the nose cone — or tip — of the Starship spacecraft.
That was likely caused by “a failure on the main fuel tank pressurization system diffuser,” SpaceX said. That’s a component that is designed to ensure that propellant moves from one place to another, spraying it in a diffuse manner rather than allowing a flood of fuel to begin sloshing or creating turbulence.
SpaceX engineers were able to replicate the issue during ground tests, the company said, and the issue was fixed by implementing a redesigned diffuser that should “substantially decrease the strain on the (fuel tank) structure.”
Similarly, SpaceX said it believes the root cause of the ground test explosion in June was “undetectable or under-screened damage to a composite overwrapped pressure vessel (COPV).”
COPV tanks, used to store high-pressure gasses, are notoriously fickle pieces of hardware because the components are meant to be extremely strong while still being lightweight. Any flaws in the tank’s structure could spell disaster when pressures are high.
“To address the issue, COPVs on upcoming flights will operate at a reduced pressure with additional inspections and proof tests added prior to loading reactive propellants onto a vehicle,” SpaceX said in a statement.
