BFR Developments

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Yazata Offline
It didn't seem to go as well as expected.

The pad is undamaged and the deluge worked as designed. Booster 9 appears to be undamaged.

But out of 33 engines, four failed to start properly and were immediately shut down by the flight computer. (The minimum for launch is 30 engines.)

Then the test seems to have been prematurely shut down by the flight computer only 2.7 seconds in. It's unknown why.

The fact that the pad is undamaged is unsurprising given the brevity of the test.

My initial observation is that engine reliability remains a serious problem for them.
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C C Offline
(Aug 6, 2023 08:46 PM)Yazata Wrote: It didn't seem to go as well as expected.

The pad is undamaged and the deluge worked as designed. Booster 9 appears to be undamaged.

But out of 33 engines, four failed to start properly and were immediately shut down by the flight computer. (The minimum for launch is 30 engines.)

Then the test seems to have been prematurely shut down by the flight computer only 2.7 seconds in. It's unknown why.

The fact that the pad is undamaged is unsurprising given the brevity of the test.

My initial observation is that engine reliability remains a serious problem for them.

I hate to say it, but as the years drag on just waiting to see if a depot starship in stable orbit can be filled with fuel from multiple refuel rocket launches, Bezos' limited, retro Moon lander is starting to look better and better. Or better than than nothing, as China bounds along closer and closer.

OTOH, the Blue Moon lander is so late in development at even getting started, and probably going the dismally slow Boeing Starliner & NASA engineering route, that any full-fledged working debut for it is probably going to be in the 2030s.
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Yazata Offline
Interesting test object rolled out of the Midbay today. It's a Starship nosecone with what looks like a pressure bulkhead at the bottom, and what might concievably be air conditioning units of some sort.

Speculation (that's all it is) is that this is some kind of mockup or test article for a future pressurized crew compartment.

(Photo from LabPadre's Rover-1 live-stream camera)


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Yazata Offline
The crew compartment test article atop an SPMT traveled a short distance down the road to the east end of the build site where it was placed near the payload integration facilities. During its short trip, labels were photographed on it that confirm that it is indeed an HLS test article.

And here's latest Mauricio's full-length update video.


https://www.youtube-nocookie.com/embed/hEyoqlzvf4k
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Yazata Offline
And this: The Coast Guard has put out a warning to mariners:

"On August 31, 2023, mariners operating offshore in waters east of Brownsville Texas are advised of rocket launching activities and associated hazardous areas which may impact navigation interests. Navigational hazards from rocket launching activity may include, free falling debris and/or descending vehicles or vehicle components, under various means of control. Mariners should avoid all waters within rocket flight trajectories originating from launch sites in the vicinity of Boca Chica Beach and Brownsville Texas."


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Yazata Offline
(Aug 6, 2023 08:46 PM)Yazata Wrote: But out of 33 engines, four failed to start properly and were immediately shut down by the flight computer. (The minimum for launch is 30 engines.)

Subsequent to the static fire, technicians were seen working on the engine starters in the Orbital Launch Mount and testing them repeatedly.

(The rocket engine turbopumps are spun up initially with high pressure gas. Since the outer twenty Raptors only start once for launch, while the inner 13 need to restart for landing, the high pressure gas cannisters and valves for the outer twenty engines are on the launch pad so as to reduce mass carried by the booster.)

So speculation (that's all it is) is that SpaceX's instrumentation has isolated the reason four engines didn't start to problems with the starters, which is being addressed.

Quote:Then the test seems to have been prematurely shut down by the flight computer only 2.7 seconds in. It's unknown why.

Speculation once again is that the computer aborted the test early because fewer than the 30 engines necessary for flight ignited. In an actual launch attempt, if they didn't have enough engines running, the launch would be aborted. The computer probably had that abort criterion written in its software.

Unknown if 2.7 seconds was enough for them to assess the effectiveness of the water deluge on reflected acoustic energy that could damage the booster, but they seem satisfied by all external indications.

Quote:My initial observation is that engine reliability remains a serious problem for them.

Or maybe not. Maybe the problem wasn't the engines at all, but rather the process external to the engines used to start them.
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