YazataAug 26, 2019 11:48 PM (This post was last modified: Aug 27, 2019 12:12 AM by Yazata.)
(Aug 26, 2019 11:36 PM)confused2 Wrote:
(Aug 26, 2019 11:21 PM)Yazata Wrote: It's already 5:20 CDT, so we are already past the original 4 pm target.
Fueling is underway and vapor venting is visible from the vehicle.
That's OK. For 90 minutes I've been watching a rocket with no fuel in it expecting it to take off at any moment.
Word is that LOX loading is complete. Not sure about the methane.
The launch is still on, since a local resident says all the SpaceX workers who have been building the other prototype are all gathered in a crowd looking at Hoppy in the distance.
The Sheriffs told the Boca Chica Village residents that police sirens will sound at the T-10 minutes mark. Presumably the police are getting that direct from SpaceX. The people running the streams should alert us when that happens.
Some speculation that they might be holding due to high winds, hoping that they die down around sunset. But that's just speculation.
SpaceX has just started a live-stream of their own:
They say the new launch time is approximately 6:00 PM CDT, official from SpaceX.
The countdown clock on the SpaceX stream says t - 6 minutes! Sirens in Boca Chica Village are howling.
Launch appears to have aborted at t + 0.8 seconds, probably by a flight control computer. It appeared that the engine never ignited. Presumably there was some problem upstream with the preburners and turbopumps.
Problem is that these engines need to be 100% reliable. Just one failure is an almost irrecoverable situation. This is the price of showmanship - when it fails it fails publicly and catastrophically. NASA probably had many failed rocket engines but kept quiet about it. Whether SpaceX can recover is another matter.
But for now they have to depressurize Hoppy and drain it of the tons of fuel and liquid oxygen it contains. There's a whole safeing process to prevent it from being a really giant pressure-cooker bomb.
(Talk about blue balls... '5-4-3-2-1'...nothing. I bet Jeff Bezos is laughing.)
Edit: Elon thinks they have found the problem. If he's right, it's no biggie.
YazataAug 27, 2019 07:31 PM (This post was last modified: Aug 27, 2019 08:45 PM by Yazata.)
Mary/Bocachicagal reports that a Sheriff's deputy came by this morning and hand delivered her another warning leaflet. Its the same as the last one, except it says the "SpaceX spaceflight activities" will take place 8-27. The time has changed from 4PM to 4:15PM specified last time to a much more realistic 4PM to 7PM their time (CDT). (These things always run late.)
It seems that the Raptor uses more complicated (and untried in real flight conditions) igniters. The old igniters were chemical, using two hypergolic chemicals that spontaneously ignite when they come in contact. The new igniters are like little blow-torches and run off the same methane and oxygen that the rocket itself uses. These little blow-torches are themselves ignited with a spark-plug type arrangement.
Good and bad: The new igniters are more complicated and are untried. But they don't depend on a finite supply of TEA-TEB (the hypergolic igniter) which limits how many times the engines can be restarted. (The very first Falcon Heavy's center core crashed into the sea when it ran out of TEA-TEB and its engines failed to ignite for their landing burn.) The Raptor is designed to be restarted over and over, as long as it has regular methane fuel and oxidizer.
It's frustrating for those watching the various live-streams which had about 100,000 viewers yesterday, from all around the world in every conceivable country. (Maybe a few on other planets... I bet they were watching on the Space Station.) But, as the engineers say, "This is why we test". Better to catch a possible igniter problem now than when an actual Starship is trying to relight its engines in order to land. That's why Hoppy is doing valuable service as a low-budget flying test stand for the new Raptor engine.
Elon talks about the new igniters in these February tweets:
Shot by local resident Austin Bernard. You are gonna want to watch this one in full screen too with the sound on to catch the reaction of the gathered space-nuts:
Here's something interesting: One of the COPVs on top of Hoppy, the carbon overwrapped pressure vessels that contain pressurized gasses, can be seen jetting off on its own right after Hoppy's landing. Not entirely surprising, considering how Hoppy is Frankenstein's spaceship seemingly held together with duct-tape. (Which is probably why it flew so well. You can accomplish anything with duct-tape.)
YazataAug 28, 2019 07:49 PM (This post was last modified: Aug 28, 2019 08:44 PM by Yazata.)
Everyday Astronaut has more videos of Hoppy's flight. In real time, in close-up and in slow-motion. He even captured the COPV come jetting off after Hoppy landed.
Everyone said Hoppy was ugly and a joke. Everyone said Elon Musk was crazy to have a bunch of pickup-driving Texas boys building a spaceship out on an open windy beach, with the entire world watching their every move, in what looked like a junkyard.
Well, Hoppy triumphed yesterday! Watertowers really can fly! Beautifully too.
Next up, the crazy Starship prototypes!
NASA and the legacy aerospace industry never did things this way, at least since the wild-and-crazy 1960's engineering era that took us from the first satellite in orbit (1957) through Mercury and Gemini to men on the Moon (1969) in just 12 years.
Elon's trying to revive the old spirit. (It's 2019! About f'ing time!!)
(Aug 28, 2019 07:01 PM)C C Wrote:
(Aug 28, 2019 12:15 AM)Yazata Wrote: Videos of Hoppy's flight.
So strange to see a clean, giant oxidizing flame on a hovering water tower instead of a cutting torch.
Hi CC, welcome back. Missed you.
Yeah, I think that the rocket exhaust looks like a blowtorch since the engine is fueled by methane. We're used to kerosene rocket fuel that burns bright incandescent. Hydrogen fueled rockets have almost invisible exhaust.
The clean methane flame makes it easy to see the engine gimbaling in the videos to balance the vehicle and send it off to the side towards its lovely landing pad. You can see those surplus Falcon 9 cold gas thrusters puffing too, as it descends and lands.
confused2Aug 28, 2019 10:29 PM (This post was last modified: Aug 28, 2019 10:30 PM by confused2.)
In the solo water tower dance section that looked like a perfect 10 to me.
@Yazata - many thanks for sharing your enthusiasm which added a lot to the experience and without which I might have missed it altogether.