Sat. Oct 1st, 2022

So what exactly are we to make of the third flight of a full prototype Starship?

If nothing else, Wednesday afternoon’s flight provided several minutes of top-notch entertainment: the rocket ship is going up. Missile ship coming down. Missile ship lands. And then, 10 minutes later, with an incredible plot twist, the rocket ship takes off again for a moment and then explodes.

It all looked remarkable. Like many of the most inspiring things SpaceX has accomplished in the past decade, this launch, landing, and subsequent explosion looked almost alien. It felt like a glimpse into the future, a glimpse of something that might yet be unseen.

SpaceX founder and chief engineer Elon Musk appeared satisfied after the flight. “The SpaceX team is doing an amazing job! One day the real measure of success will be that Starship flights are mundane,” he tweeted

So the Starship program is clearly making progress. But will it get where it needs to be? Three explosions in three flights are hard to ignore.

What happened

Let’s start with the technical details of Wednesday’s launch. Like the flights of SN8 and SN9, SN10 rose to an altitude of about 10 km in December and February respectively. This flight looked smoother than the previous climbs, but that could be an optical illusion. Like those previous flights, SN10 then performed a belly flap maneuver and began to fall to Earth.

SN10 flight and destruction, from 5 miles away, shot down by Trevor Mahlmann.

Unlike the previous flights, this vehicle had no problems re-igniting the Raptor engines. All three ignited as the vehicle approached the ground, and then one was knocked out by design. With two engines, the vehicle completed its reorientation to a vertical position. Then, as intended, the vehicle landed slowly on the single engine landing pad.

SpaceX engineers have had some issues with Starship’s stubby landing legs — they’re probably a temporary design fix, and at least some of them should have been crushed by Wednesday. It also appeared that Starship has bounced back momentarily. But the vehicle hit the ground and although it leaned, with a little fire at the base, it bounced back to the ground in one piece.

It stood there for about 10 minutes. Suddenly, the vehicle came up short in a violent explosion and crashed back into the path. SN10 was no more. SpaceX has not yet given any details on what happened and probably won’t. However, informed sources suggested the accident may have been caused by a leaking valve, likely methane fuel. It is notoriously difficult to operate fuel valves at cryogenic temperatures.

Takeaways

SpaceX engineers should be glad they discovered the annoying propellant and Raptor relighting problems that had sunk the two previous landing attempts. This was a consistent problem with the Falcon 9 program and simpler Merlin engine design in making a successful landing. It is noteworthy that a spaceship lands at high altitude only after its third flight.

Also, SpaceX will take a lot of meaningful data from this launch, flight and landing that it can use to refine both the Starship’s design and its flight software.

What we don’t know is how NASA will see this. Will it be considered progress? Or as a negative, with the third destruction of a spaceship in three flights? This matters as the agency moves closer to a down-select for its Human Landing System contract next month, allowing billions of dollars to flow into SpaceX for its Starship program — or not. NASA may decide to go with more conventional landers under development by teams led by Blue Origin and Dynetics.

That said, NASA isn’t stupid. Starship undergoes a unique development program, progressing through rapid iterations and taking risks through design. Every failed mission buys risks for future flights. It’s no coincidence that SpaceX builds a new spaceship in South Texas every two or three weeks. Because you are rich in hardware, you can act fast, try, fail, try again and finally succeed.

SpaceX first used this method to develop the Falcon 1 rocket, which entered orbit in 2008 after several failures. And Musk now believes this method offers the most direct path to launching Starship into orbit by the end of this year or early next. Enough good things happened on Wednesday to believe he might be right.

List image by Trevor Mahlmann

By akfire1

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