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BFR Developments

Yazata Offline
(Jul 16, 2019 04:04 AM)Yazata Wrote: So... the untethered free-flight probably won't be Tuesday. It might have slipped to Wednesday (hopefully).

Elon verifies that they are now shooting for Wednesday for the un-tethered free-flight.

https://twitter.com/elonmusk/status/1151152285449220096

But today should still be exciting, since everybody thinks that they are planning a static test fire today. (The engine will be ignited while the vehicle remains tied down.) Probably around sundown, Texas time.

Watch on LabPadre's live-stream. It's going right now.

https://www.youtube.com/watch?v=fhl6KJnj1yE

And for your added enjoyment, Tim Dodd the Everyday Astronaut will be streaming too, with his commentary. His stream starts in 3 hours.

https://www.youtube.com/watch?v=ACYW4RDCS90

There may be another stream here

https://www.spadre.com

Edit: pad cleared and roadblocks up.

Edit 2: BCG reports that the SpaceX firetruck was seen headed to the pad. No visible sign of a fire. Perhaps a safety precaution for fuel loading. Pad isn't clear since a man in a hard hat and orange vest was seen by the methane tanks. And something strange -- a red car was seen heading for the pad, then driving away at a high rate of speed. The car appeared to pull off the road onto dirt and a cloud of dust went up, when the dust settled, no red car. Are they having trouble with unauthorized intruders?

Edit 3: A whole group of men in hardhats and orange and yellow vests near the base of the Hopper.

Edit 4: Pad seems to be clear again. The SpaceX fire truck was last to leave. Here it is passing through the road block on its way out.


[Image: 1570394.jpg]
[Image: 1570394.jpg]



Edit 5: People on the scene (BCG & company) say they think that fueling has started. No vapor clouds and only minor activity at the flare stack, but there's a distinctive noise that one hears when they are moving fuel and oxidizer around.

Edit 6: Vapor is now clearly visible. Talk is that engine ignition should be within an hour.

Edit 7: Intense flaring. Blue lights turned on under the rocket. (Apparently for better photos by SpaceX cameras.) Word is that engine is being chilled prior to ignition. Ignition should be 10:30 CDT. T-10 minutes.

Edit 8: Engine Ignition!! After the engine shut off, there was flame under the Hopper. Flame suppression came on, and a huge ball of flame erupted! (Bigger than the hopper is tall!) Does water react with a methane fire like water on a grease fire?

It appears to be out now and the Hopper is still superficially intact. The engine may or may not be toast though.

Video of the event here:

https://twitter.com/NASASpaceflight/stat...5702965250

It appeared to my layman's eye that the fire/explosion may have been unburned fuel and oxidizer. It didn't seem to me to originate at the engine, but over towards the rim of the rocket's bottom by a landing leg. (That's why I originally thought the flame was a reflection of the flare stack.) That's where the ground unbilicals connect and fuel and oxidizer are loaded and off-loaded. So did something shake loose?
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C C Offline
So much for the flight tomorrow. At least it's still intact, barring another explosion from that leaky flame.
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Yazata Offline
(Jul 17, 2019 04:32 AM)C C Wrote: So much for the flight tomorrow.

That's not going to happen, for sure.

Quote:At least it's still intact, barring another explosion from that leaky flame.

Hopefully SN6 is intact. But even if it is, it will have to be inspected minutely.

I still think that the engine might not be at fault, that the culprit was a fuel leak. Did a pipe shake loose and break? Did an umbilical come loose? Did a fuel tank rupture?

Whatever, tomorrow's not going to give us our long-awaited free-flight. But BCG's morning photos might give the world's rocket-scientists some idea what went wrong and what damage was done.

This is why they have that SpaceX firetruck, I guess.
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Yazata Offline
Photos this morning show the Hopper to be superficially intact. In fact, there's nothing visibly wrong with it.

https://twitter.com/austinbarnard45/stat...7519948800

The engine looks fine

https://twitter.com/TrevorMahlmann/statu...0528450560

The engineers in the spectator's gallery seem to mostly think that it looked worse than it was. (Provided that SN6 is ok.) The worst fire seems to have been where the umbilicals attach. The fires elsewhere were probably methane pressure valves releasing methane vapor that ignited, and maybe a vapor leak at the tank access port on the side. Down at the umbilical there might have been a failure of a backflow valve and liquid CH4 was flowing back out through the same lines they used to fuel the thing. Or vibration from the engine run shook something loose. (The Hopper is Frankenstein's Spaceship, with all kinds of ad-hoc piping and cable runs on its surface.) The big fire-ball seems to have been correlated with the activation of the remote-controlled fire suppression system, leading to the hypothesis that the water might have flash-vaporized cold liquid methane that the water hit and a big flare resulted, like in a kitchen grease fire. No loud 'boom' was heard, so it appears to have been a flare rather than an explosion. No visible damage to the Hopper (apart from the leaks which we assume are there).

The data that they got from SN6's little five second run might be of more interest to the SpaceX engineers. That's a lot of time in engineering terms (5000 milliseconds) and if SN6 ran well, that good news might overshadow the subsequent fire. The engineers should be able to observe the engine start-up, shut-down, whether any weird vibrations developed and so on.

Edit: This episode does show that there are risks in firing a large rocket engine at a concrete slab not far away, instead of into a Cape Canaveral style flame duct. At Boca Chica the rocket exhaust is reflected back upwards.

My guess is that this little crisis will throw off their schedule, but probably not for as long as feared. (Provided again, that the engine is ok.) The umbilical system needs work, as do various valves and seals. But that's relatively easy stuff to fix.

Where we stand now:

https://twitter.com/LabPadre/status/1151527796411392001

Summary

https://twitter.com/NASASpaceflight/stat...2125147138

Good static fire (5 secs).
Methane discharge ignited.
Hopper detanked and powered down fine.
Looks totally OK this morning.
Hop schedule TBD.
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Yazata Offline
Elon's tweeting again! Just two hours ago.

https://twitter.com/elonmusk/status/1151950403874914304

Somebody asked: "Starhopper is ok?"

Elon: "Yeah, big advantage of being made of high strength stainless steel: not bothered by a little heat!"

Somebody asked: "What happened? Fireball?"

Elon: "Post test fuel leak, but no major damage."

Elon: "Aiming for hover test next week."
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C C Offline
(Jul 18, 2019 11:39 PM)Yazata Wrote: Elon's tweeting again! Just two hours ago.

https://twitter.com/elonmusk/status/1151950403874914304

Somebody asked: "Starhopper is ok?"

Elon: "Yeah, big advantage of being made of high strength stainless steel: not bothered by a little heat!"

Somebody asked: "What happened? Fireball?"

Elon: "Post test fuel leak, but no major damage."

Elon: "Aiming for hover test next week."


Of course, they'll probably have to test the engine beforehand again and invite another postponing technical glitch (as if discovering a bad would be better when it's hovering). Barring massive fog or something, at least weather sensitivity isn't so much a delay factor with these type tests.
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Yazata Offline
Road closures announced for next week.

Monday 7-22, Wednesday 7-24 and Thursday 7-25.

http://www.co.cameron.tx.us/wp/space-x/

Not sure what that Monday closure is for. Maybe pressurization tests to check the new valves and seals to make sure there aren't any new leaks. Probably a checkout of improvements to the umbilical disconnect designed to unplug all the fuel and oxidizer lines when the thing takes off. (I think that was where Tuesday's fuel leak originated.) I don't anticipate that it's going to be another static engine-fire. So the free-flight is apparently penciled in for Wednesday with Thursday as a backup date.

New NOTAMs and TFRs haven't been posted yet.
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Yazata Offline
Elon's tweeting again! About three hours ago.

https://twitter.com/elonmusk/status/1152367082018754561

"Texas and Florida Starship prototypes (not Hopper) fly in 2 to 3 months."

Somebody asked it these flights will be livestreamed.

"I suspect many besides SpaceX will livestream these flights. Won't be subtle."

Somebody asked: "So vehicle will achieve orbit at some point during test regimen?"

"2 to 3 months after that."

Of course this might be something that Einstein would absolutely love: Elon Time. Proof that time is relative. Six months for Elon might be six years for me.

Especially given what happened Tuesday, some of these test prototypes are inevitably going to be lost. But after decades of NASA sloth going nowhere, I do love to see Elon goosing SpaceX to develop amazing new technology at Warp Speed.

If it doesn't contradict the laws of physics, SpaceX should be able to engineer it! And if they can engineer it, they should have finished it yesterday!

It's the old 1960's 'Space Cowboy' spirit finally returned to space travel. That's what I love to see. (And the fact that robot guidance systems are so much better today might prevent people from getting killed. Most of the test-flying can be unmanned.)

In other news, BCG has spotted that they are preparing to install a fuel-tank bulkhead in the Boca Chica Starship prototype.

https://twitter.com/BocaChicaGal/status/...3013938176

And in other BCG news, Mary spotted them unpacking what looked like new pumps for the remote control launch-pad fire-suppression system. Maybe they thought that they didn't have enough pressure/volume on Tuesday.
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C C Offline
(Jul 20, 2019 03:30 AM)Yazata Wrote: . . . And in other BCG news, Mary spotted them unpacking what looked like new pumps for the remote control launch-pad fire-suppression system. Maybe they thought that they didn't have enough pressure/volume on Tuesday.


Seemed pretty slow-poke the other night about getting down to business, too. Although maybe that was a subjectively skewered perception of the time interval. Due to it feeling like ages beforehand that the local commentators were debating whether those were real fires issuing from the craft itself or just reflections on its surface from the neighboring burn-off of unused methane.
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Yazata Offline
They are powering ahead. Mary/BCG's latest closeups (Saturday morning) of the Hopper show that the tie-down tethers have been removed from its landing legs. That definitely suggests that the promised hover test is next up, and that they won't be conducting another static test fire. Presumably SN6 behaved sufficiently well on Tuesday to satisfy them. (Despite the clunky Steampunk Spaceship that it's attached to not doing quite so well.)
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