Starship tested further, Flight Test 10 slips out two days.

The last date I had for Flight Test 10 was Friday, August 22nd at 7:30 PM EDT.  As testing has proceeded, they've rescheduled that out two days to Sunday, the 24th, at the same time.  Without double-checking, I think every test flight launch this year has been scheduled for 7:30 PM EDT, that's 2330 UTC, and the reason for the shift from mornings in Texas to evenings is for better lighting in the landing zone they're aiming for near Australia. 

This afternoon, SpaceX received launch approval from the FAA.  They had run a "Spin Prime" test on Starship 37 Wednesday afternoon, and signs were it went as expected, since after that test, crews rolled the ship back to a nearby hangar for engine inspections, touch-ups to its heat shield, and a handful of other chores to ensure it's ready to fly.  

With this flight, SpaceX officials hope to put several technical problems with the Starship program behind them. SpaceX is riding a streak of four disappointing Starship test flights from January through May, and and the explosion and destruction of another Starship vehicle during a ground test in June.

At the start of this year, SpaceX had some ambitious goals with the new version of the ship.  Perhaps the most important goals were to recover and reuse Starships then to refuel another rocket in orbit.  The second one has been talked practically as long as any exploration of space has been seriously studied.  These (and more) are important to SpaceX for their stated goal to start settling Mars (with or without NASA).

Meanwhile, NASA is eager for SpaceX to reel off these tests as quickly as possible because the agency has selected Starship as the human-rated lunar lander for the Artemis Moon program. Once operational, Starship will also be key to building out SpaceX's next-generation Starlink broadband network.

At the announcement that the FAA had cleared Test Flight 10, the FAA spokesperson said:

"The FAA oversaw and accepted the findings of the SpaceX-led investigation," the federal regulator said in a statement. "The final mishap report cites the probable root cause for the loss of the Starship vehicle as a failure of a fuel component. SpaceX identified corrective actions to prevent a reoccurrence of the event."

That "probable root cause" was seen and reported by telemetry almost as soon as Starship had cleared the tower.  No, that's just an exaggeration.  It was more likely to have been around the time the booster was dropped. 

SpaceX identified the most probable cause for the May failure as a faulty main fuel tank pressurization system diffuser located on the forward dome of Starship's primary methane tank.  The diffuser failed a few minutes after launch, when sensors detected a pressure drop in the main methane tank and a pressure increase in the ship's nose cone just above the tank. 

The rocket compensated for the drop in main tank pressure and completed its engine burn, but venting from the nose cone and a worsening fuel leak overwhelmed Starship's attitude control system. Finally, detecting a major problem, Starship triggered automatic onboard commands to vent all remaining propellant into space and "passivate" itself before an unguided reentry over the Indian Ocean, prematurely ending the test flight.

Among the many goals of the next test flight is that modifications to the various heat shield elements on Starship are to be tested.  Several different, new, ceramic and metallic tile designs have been placed in various places around the ship.  Starship successfully made it through reentry for a controlled splashdown in the Pacific several times in 2024, but sensors detected hot spots on the rocket's stainless steel skin after some of the tiles fell off during launch and descent. 

Making the Starship upper stage reusable like the Super Heavy booster will require better performance from the heat shield. The demands of flying the ship home from orbit and attempting a catch at the launch pad far outweigh the challenge of recovering a booster. Coming back from space, the ship encounters much higher temperatures than the booster sees at lower velocities.

While the ship is the star of the show, there are also experiments and trials planned for the SuperHeavy booster.  

Engineers also plan to put the Super Heavy booster through the wringer on the next launch. Instead of coming back to Starbase for a catch at the launch pad—something SpaceX has now done three times—the massive booster stage will target a controlled splashdown in the Gulf of Mexico east of the Texas coast. This will give SpaceX room to try new things with the booster, such as controlling the rocket's final descent with a different mix of engines to see if it could overcome a problem with one of its three primary landing engines. 

SpaceX completed a six-engine static fire of the next Starship upper stage on August 1. Credit: SpaceX

As many times as SpaceX has said it, it's almost a cliche' we automatically quote. The purpose of the test is the data they acquire.  

"Every lesson learned, through both flight and ground testing, continues to feed directly into designs for the next generation of Starship and Super Heavy," SpaceX said. "Two flights remain with the current generation, each with test objectives designed to expand the envelope on vehicle capabilities as we iterate towards fully and rapidly reusable, reliable rockets."