Moderators: richierich, ua900, PanAm_DC10, hOMSaR
flyingturtle wrote:Just a few questions...
- has the Starship size been finalized? Until SN8, there has been a progression of larger test vehicles, starting with Hoppy. AFAIK the current Starships have small tanks, ones that only have to supply atmospheric Raptors for 4-ish minutes of powered flight.
- has there been any indication of when the Booster will be first flown, e.g. for hover tests?
casinterest wrote:From this angle. you can tell that the trigger for the explosion was probably the lack of water being pumped on the bottom. less than 10 seconds after the water stops, the rocket explodes. The water was probably helping to disperse the Methane that was leaking.
flyingturtle wrote:casinterest wrote:From this angle. you can tell that the trigger for the explosion was probably the lack of water being pumped on the bottom. less than 10 seconds after the water stops, the rocket explodes. The water was probably helping to disperse the Methane that was leaking.
I don't agree. Water does not disperse a gas very well, and methane isn't that water-soluble either. Water only cools incendiary sources, like hot engine parts.
It's a tiny bit like the burning Notre Dame cathedral - walls and roofs that protect the hot stuff from the nasty water.
A fan wouldn't have helped either, because of the skirt.
ThePointblank wrote:It appears they are zeroing in on the cause of the explosion of SN10; the rocket suffered a hard landing, with thrust being low despite the engine being commanded high, per a tweet from Elon:
https://twitter.com/elonmusk/status/1368016384458858500
Elon is suggesting that they will instead have a minimum of two engines all the way to the ground & restart the third engine if engine 1 or 2 have issues.
ThePointblank wrote:It appears they are zeroing in on the cause of the explosion of SN10; the rocket suffered a hard landing, with thrust being low despite the engine being commanded high, per a tweet from Elon...
Stitch wrote:ThePointblank wrote:It appears they are zeroing in on the cause of the explosion of SN10; the rocket suffered a hard landing, with thrust being low despite the engine being commanded high, per a tweet from Elon...
Not all of the landing struts locking on deployment (you can clearly see about half of them just swaying in the slow-motion) didn't help, either.
Nomadd wrote:SN11 is on it's way to the pad. It almost ran over a snail, but the snail managed to outrun it.
Tugger wrote:What are/will be the planned changes from "old type" to "new type"?
Tugg
The major hardware that exists or will be built includes:
Two orbital launch pads, one of which is already under constriction
Two suborbital launch pads, one of which already exists
Two landing pads, one of which already exists
Two structural test stands for Starship and the Super Heavy booster
A large "tank farm" to provide ground support equipment for orbital flights
A permanent position for the totemic "Starhopper" vehicle at the site's entrance
What is striking about this architectural drawing is its compact nature, largely because SpaceX has limited land to work with at the facility and must include stormwater ponds to mitigate against flooding. All of these facilities will be concentrated within a couple dozen acres, which is in stark contrast to more expansive launch sites in Florida at Kennedy Space Center and Cape Canaveral Space Force Station.
mxaxai wrote:Doesn't the proximity of the launch and landing facilities risk damage to the neighbouring pads, and to vehicles waiting for launch there, in case of an explosion?
If that's not an issue, why did NASA build their stuff so far apart at KSC in the first place?
zanl188 wrote:mxaxai wrote:Doesn't the proximity of the launch and landing facilities risk damage to the neighbouring pads, and to vehicles waiting for launch there, in case of an explosion?
If that's not an issue, why did NASA build their stuff so far apart at KSC in the first place?
Complex 39 was designed for LOX/Hydrogen boosters. Much more energetic than LOX/RP1 combo SpaceX is using.
Tugger wrote:I love the blue collar nature of that picture.
A friend of mine has always been annoyed at the perception people have of engineers. He terms himself a "Bluecollar Engineer" to make it clear to people that there is hard dirty work involved. Good engineering is not just "design on a computer" (though there are many engineers like that). As he puts it "a real engineer will get their hands dirty, see what and how their design/enginneering does in the real world" and that is the only way to "learn to become a real engineer not just a computer jockey".
Tugg
Fair point. If autogenous pressurization had been used, CH4 bubbles would most likely have reverted to liquid.
Helium in header was used to prevent ullage collapse from slosh, which happened in prior flight. My fault for approving. Sounded good at the time.
Might just catch the ship with the launch tower, same as booster
Yeah, we talked about that internally. Could just have it land on a big net or bouncy castle. Lacks dignity, but would work. But, optimized landing propellant is only ~5% of dry mass, so it’s not a gamechanger.
Tugger wrote:A friend of mine has always been annoyed at the perception people have of engineers. He terms himself a "Bluecollar Engineer" to make it clear to people that there is hard dirty work involved. Good engineering is not just "design on a computer" (though there are many engineers like that). As he puts it "a real engineer will get their hands dirty, see what and how their design/enginneering does in the real world" and that is the only way to "learn to become a real engineer not just a computer jockey".
Nomadd wrote:I had the misfortune to be in companies where the worst insult they had was "Scarier than an engineer with a screwdriver".
zanl188 wrote:.... and SpaceX launches, and lands, a Falcon 9 for a record ninth time. We live in exciting times.....
GDB wrote:A third of that 9th booster's missions have been since December.
I think we are getting a better picture of how resilient they are now.
Nomadd wrote:GDB wrote:A third of that 9th booster's missions have been since December.
I think we are getting a better picture of how resilient they are now.
That booster just passed the Skylab Saturn 5 for payload launched and has now lifted more than any booster in history. It just took a few tries.
Nomadd wrote:This is one bigass booster. 9 meters wide and 70 meters tall. It just needs a 50 meter tall Starship on top to complete the picture.
*This camera is connected to the computer through a piece of Cat 6 scavenged from the wreckage of SN 10.*
Francoflier wrote:There's a few things I don't get about their stacking approach... Are they really using Tankzilla (through the high bay roof) to lift and stack the booster sections? I notice they were using smaller cranes to stack Starships as well.
You'd think the main purpose of having built a large hangar for stacking would be the benefit of having a gantry crane in the ceiling, along with a way to laterally stabilize the sections so they wouldn't dangle about the way that booster piece did?
*edit* Nevermind, just watched yesterday's NSF video showing the gantry crane being delivered.
Also, I didn't realize the High bay was only tall enough for the booster. What's their plan for final stacking? I can't see anything tall enough to do that anywhere on site...
FGITD wrote:Very unusual launch of sn11. Too foggy to really see much, and now it appears the vehicle broke apart midair while doing the landing flip.
Really looking forward to what spacex has to say about this one. After coming so close last time, it's too bad
Looks like engine 2 had issues on ascent & didn’t reach operating chamber pressure during landing burn, but, in theory, it wasn’t needed.
Something significant happened shortly after landing burn start. Should know what it was once we can examine the bits later today.
Francoflier wrote:Again, there was a fire near the base of one of the engines since early in the launch, I'd say from a methane leak.
The telemetry, at least the video part of it, was crap throughout.
And again, it seemed there was a problem with Raptor ignition for the landing burn and another RUD, eerily shrouded in fog, and seemingly more violent than even the previous ones.
One step forward, 2 steps back...
It may be time for SpaceX to take a break from testing and take a closer look at their design, here. I have the feeling the Raptor is not quite there yet, or at least the part where it re-ignites from horizontal freefall. That violent 90 degrees rotation doesn't seem to play nice with fuel and/or oxidizer flow,
I wonder whether the FAA is starting to lose patience. How many giant rockets need to crash out of control and explode near a populated town before they start raising an eyebrow?
kanban wrote:This can't be cheap... reminds me of the question "what's the difference between a rat and a human?" Ans: after 2 failures a rat looks for a different approach where as a human will keep doing the same approach hoping for a better result.
They need to to stop hoping for a different conclusion and go back to the drawing board.
texl1649 wrote:I think I read this am that Elon said SN15 to the pad in ‘a few days.’ This rapid iterative prototype/testing process is fun to watch, and I expect they will have a fresh analysis of what went wrong with the relight this time.
casinterest wrote:aumaverick wrote:Why did SN9's body (1/4 up from base) and nose cone appear to be frosted during the flight? Was there a leak somewhere causing the steel to freeze?
That is the frozen fuel condensation freezing on the outside. You can see it on the pad as well. There isn't much insulation on starship right now.
https://space.stackexchange.com/questio ... he-vehicle
All the rockets form ice on the pads with the low temperature liquid fuels.
texl1649 wrote:Francoflier wrote:Again, there was a fire near the base of one of the engines since early in the launch, I'd say from a methane leak.
The telemetry, at least the video part of it, was crap throughout.
And again, it seemed there was a problem with Raptor ignition for the landing burn and another RUD, eerily shrouded in fog, and seemingly more violent than even the previous ones.
One step forward, 2 steps back...
It may be time for SpaceX to take a break from testing and take a closer look at their design, here. I have the feeling the Raptor is not quite there yet, or at least the part where it re-ignites from horizontal freefall. That violent 90 degrees rotation doesn't seem to play nice with fuel and/or oxidizer flow,
I wonder whether the FAA is starting to lose patience. How many giant rockets need to crash out of control and explode near a populated town before they start raising an eyebrow?
You don’t really know what the telemetry was, just the video feed they put on YouTube. That’s the toughest data stream to maintain (moving picture), and they did pretty well with it, as well as the camera outside, and inside the tanks.
Finally, the RUD did happen, yes, but it’s also proven again the ship can fly, belly flop to terminal velocity, and then they’ve had trouble yes with the raptors. Significant changes in engineering are reported on the reworked raptor for SN15, as well as ‘over a hundred’ changes for the ship itself. I think I read this am that Elon said SN15 to the pad in ‘a few days.’ This rapid iterative prototype/testing process is fun to watch, and I expect they will have a fresh analysis of what went wrong with the relight this time. Elon also said they are expecting to add ‘several thousand’ employees at the Boca Chica site over the next couple of years.
It did explode/terminate; right over the launch pad. I get it, some hate this company for threatening the entrenched players, but let’s not be dramatic about this event threatening a population center.