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BFR Developments

#41
Yazata Offline
New NOTAMs announcing TFRs for Tuesday, Wednesday and Thursday. Each one starts at 2:00 PM and runs to 10:00 PM CDT.

https://tfr.faa.gov/tfr2/list.html

Elon Musk commented this (April 2) morning on twitter about what's delaying the Hopper:

https://twitter.com/elonmusk/status/1113000800526036992

"Some challenges with ice formation in the cryogenic propellant prevalves. Hopefully overcome soon."

Unleash the engineering geeks!

They immediately homed in on Elon's use of the word "in" rather than "on". Either it was a mistake, or else this isn't a matter of air moisture in humid Texas freezing around the outside of the cold lines and valves.

One on NSF wrote this: "I believe to what Elon is referring is that CH4 has a nasty habit of forming Methane Hydrate and Clathrate Hydrate ices at certain Temp/Pressure conditions. CH4 and associated tanks, lines, storage need to be VERY DRY."

So there's speculation about whether we will see methane dryers appearing at Boca Chica.
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#42
stryder Offline
(Apr 2, 2019 06:16 PM)Yazata Wrote: New NOTAMs announcing TFRs for Tuesday, Wednesday and Thursday. Each one starts at 2:00 PM and runs to 10:00 PM CDT.

https://tfr.faa.gov/tfr2/list.html

Elon Musk commented this (April 2) morning on twitter about what's delaying the Hopper:

https://twitter.com/elonmusk/status/1113000800526036992

"Some challenges with ice formation in the cryogenic propellant prevalves. Hopefully overcome soon."

Unleash the engineering geeks!

They immediately homed in on Elon's use of the word "in" rather than "on". Either it was a mistake, or else this isn't a matter of air moisture in humid Texas freezing around the outside of the cold lines and valves.

One on NSF wrote this: "I believe to what Elon is referring is that CH4 has a nasty habit of forming Methane Hydrate and Clathrate Hydrate ices at certain Temp/Pressure conditions. CH4 and associated tanks, lines, storage need to be VERY DRY."

So there's speculation about whether we will see methane dryers appearing at Boca Chica.

We'd usually refer to them as a Knock Out Pot (wikipedia.org) especially useful when dealing with Natural Gas since it's make-up is constituted by a lot of moisture. For instance pulling gas from a Landfill site will include drawing moisture from Leachate (wikipedia.org) which technically has to go through seperators because it can otherwise pollute the water table.

I'd assume (assumption not necessarily absolutely true) in the case of rocketry however, they should be dealing with purified gases as opposed to dirty types. I'm therefore not so sure that the concerns would be the moisture inside the pipes, but the concern of the extremis. If it's not insulated enough to deal with the temperature changes and the insulation itself can hold a factor of moisture then it could cause a cascading damage effect where the insulation becomes less and less effective. (There is also the problem that the sun beating down "bleaches", if the UV levels breakdown insulation foam significantly it can be a problem)
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#43
Yazata Offline
Photos this morning showed the Hopper site seemingly deserted. Then later in the morning lots of liquified gas tankers arrived and offloaded. Around midday it got crowded. Multiple trucks parked by the Hopper, even a firetruck (just in case, I assume). Now about 6:30 PM they are all clearing out. Don't know if they are going to try (again) to fire it up, or whether they are just quitting for the day.

Edit: The Hopper looks to be all fueled up. It's illuminated after sunset in weirdly beautiful golden light which is apparently the work of a new set of LED worklights that arrived yesterday. (And dutifully photographed by BCG.) There's also an exceedingly bright beacon light that appeared yesterday that I assume is meant to be visible to aviators marking the center of the no-fly zone. Lots of white vapor venting from the bottom, but still no ignition. They seem to have gotten to the same point where they got stuck in previous days.

Edit 2: Big LOX cloud at base of Hopper and another giant flare suggest the vehicle is being emptied of fuel and oxidizer. Looks like that's it for today. Kind of disappointing. They were working on the thing all day, but apparently to no effect.

I guess this is what real engineering looks like. The kind where geeks tear their hair out, bashing their heads against intractable problems. It isn't all the wonderful finished triumphs like landing rockets, delivering Little Earth to the Space Station and shooting red Teslas past Mars. But they are gonna solve this latest problem one of these days and things will move on to the next challenge.
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#44
Yazata Offline
They just lit it up! 7:56:26 pm CDT (5:56 PDT, 12:56 AM UTC). Only for a second, which was expected. The Hopper was tied down and didn't fly so it was a static test of the engine ignition, pumps and plumbing. This is the first-ever firing of a full-flow staged-combustion rocket engine on an actual vehicle and not just an engineering experiment on a test stand. (It's a very complicated engine.)

https://en.wikipedia.org/wiki/Staged_combustion_cycle

It happened after sunset, in the fog. Here it is from six miles away. The small flame on the right is now-familiar flare stack. The big flame on the left is rocket blast coming out from under the Hopper. Hopefully the Hopper is still there and not the victim of what Elon calls a Rapid Unscheduled Disassembly. I'll be interested to see photos of it tomorrow morning. Hopefully BCG will come through.

Photo from Labpadre's video feed.

https://www.youtube.com/channel/UCFwMITS...6PoJoh1OUQ


[Image: 1554363.jpg]
[Image: 1554363.jpg]



Short little videos here from the two live webcams:

https://twitter.com/NASASpaceflight/stat...3924372480

Elon Musk reacting

https://twitter.com/elonmusk/status/1113613409767964673
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#45
Yazata Offline
Nerves-of-Steel BocaChicaGal to the rescue! Check this video out that she shot from (relatively) close by in Boca Chica! (I don't believe she is quite as close as it seems, it's a long lens.)

Apparently the loud honking sound at the end of the video is really the sound this rocket engine makes when it shuts off. It reportedly made the same sound on the test stand at McGregor. After the smoke clears, the Hopper looks intact.

https://www.youtube.com/watch?time_conti...0RwWWE-aAQ
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#46
C C Offline
What's it been -- two weeks or more that both an online (and a physical?) crowd have been hovering on the fringes and suffering disappointments, waiting to witness this event? They finally got to smoke a cigarette.

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#47
Yazata Offline
(Apr 4, 2019 06:50 PM)C C Wrote: What's it been -- two weeks or more that both an online (and a physical?) crowd have been hovering on the fringes and suffering disappointments, waiting to witness this event? They finally got to smoke a cigarette.

And I was one of them!
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#48
Yazata Offline
Another test firing Friday evening.

Conditions were too foggy to see anything much on the two live webcams, but it definitely seems to have lit up for about a second.

https://twitter.com/NASASpaceflight/stat...2717424640

The two webcams are 6 miles away at South Padre Island.

But BCG was watching (and reporting on trucks driving up to and away from the vehicle during the day), so hopefully she caught this second firing more clearly from close up. (I believe that she's a safe distance away when the police roadblocks are up, and right outside the fence many times when they aren't.) She seems to know what to photograph too, and her detailed photos get lots of attention from the engineering geeks, who discuss all the lines running into the Hopper, how they are connected to the vehicle and what various pieces of equipment pointed at it are. (IR and visual cameras, high intensity worklights and things like that.) They were even dissecting her video of the first firing frame by frame, to see how the engine ignited. Reminded me of the National Reconnaissance Office interpreting spy satellite photos pixel by pixel.

The attitude is that this is engineering history and if it finally ends up in delivering humans to the Moon and Mars, they want to be documenting it step by tiny step, trips and stumbles and all. To say nothing of the fact that it's absolute catnip to anyone with a drop of engineering flowing in their veins.

Edit: About one minute ago Elon Musk posted this on twitter

https://twitter.com/elonmusk/status/1114390314565787648
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#49
confused2 Offline
One small step ... on the way to Mars. I really do think that is what we are seeing.
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#50
C C Offline
(Apr 6, 2019 05:29 AM)Yazata Wrote: The attitude is that this is engineering history and if it finally ends up in delivering humans to the Moon and Mars, they want to be documenting it step by tiny step, trips and stumbles and all.


Let's hope it has a happy ending like that, and the footage doesn't instead appear in the 21st-century's version of a Spruce Goose documentary. At least it's definitely going to get to "fly" more than once.

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