Engineers could make another attempt to launch Starship as soon as Friday evening.
See full article...
See full article...
Ground system issue scrubs first launch of SpaceX’s Starship V3 rocket
- Thread starter JournalBot
- Start date
In the past I’ve always heard that rockets with several engines need to slightly stagger the engine startups to reduce stresses due to pressure spikes, vibrations and such.
But now the Starship V3 booster will start all 33 Raptors simultaneously.
Anyone know how they solved the problems with simultaneous engine startup?
But now the Starship V3 booster will start all 33 Raptors simultaneously.
Anyone know how they solved the problems with simultaneous engine startup?
Upvote
3
(3
/
0)
Both 11 million pounds and 5000 metric tons are meaninglessly large numbers to people. Unless someone is familiar with the actual mechanics and engineering of how much space that kind of thing takes up in a system like this, it's pointless and arguably worse to switch to a form of measurement other than the one actually used by the organization doing the thing. And for those who are familiar with it, there's no need to change either, because they're already familiar with it.I get that 11 million is a large number that reads impressive, but it's also completely meaningless to me and I guess a lot of other readers. Personally I think that 5000 metric tons gives a much better impression of scale. Please and thank you
Upvote
18
(20
/
-2)
I'm sure part of it has to do with how few parts there are on the Raptor 3s... meaning way less stuff that could get damaged by vibrations. See
View: https://www.reddit.com/r/EngineeringPorn/comments/1eix9bv/a_spacex_raptor_v1_engine_compared_to_the_new_v3/
for a comparison of Raptor V1 vs V3.
Upvote
17
(18
/
-1)
I fully understand this view and agree. I have watched most of SpaceX's launches when it was new (go F9 and FH) then as they became routine (and could we have imagined that before SpaceX?) I'd catch the occasional F9 launch and booster landing for I love me my Earth from space Videos.
Of course, I was also there at the first SH hop and watched each test. Then Musk goes off the rails and I had to make a choice, what was I supporting in my watching, Musk/SpaceX or SpaceX/Future of Humans in Space. it was the latter (go engineers)
So now, when it comes time for a new test launch of SH/SS I ignore any of the Musk Rah Rah crap, focus back when they go back to the launch and watch the future unfold.
I could not watch yesterday's attempt (conflicts), but when Nikki appeared, I would have turned the sound down, opened another browser window and scanned some article till her face was off the screen. Then it would be back to the regularly scheduled show again.
Upvote
15
(17
/
-2)
It's not especially prominent. They use a lot of names - including 'block', as I said. 'Version' is a word that the public easily understands, and that is used by countless companies. Perhaps they are more inclined to use it rather than just a number (like Ariane for example) because of the rapid iteration process.
Anyway this argument about the name is very silly. And now you have missed your chance to pretend it was satire.
Upvote
21
(21
/
0)
At least part of it was replacing the downcomer with a much larger one (the size of an F9 Booster!) to greatly increase fuel flow and double as the landing tank.
Upvote
22
(22
/
0)
The Falcon 9 launch vehicle development effort went through five versions called "Blocks" as in Falcon 9 Block 5, which has been the workhorse for SpaceX since it was first launched on 11May2018. The F9B5 has been launched 584 times over the past 8 years with 583 successful launches (99.83%) and has landed safely 580 times (98.7%).
Last edited:
Upvote
5
(6
/
-1)
Presumably the errant pin did retract as expected during the previous wet dress rehearsal?
Upvote
-1
(1
/
-2)
What is the engineering reason for driving the water this way? I mean pumping huge quantities of water is something industry does every day (say cooling nuclear reactors or pumped-hydro) with electrically driven pumps (or diesel, whatever). Is there some reason you use gas to drive it that isn't obvious at first glance? Didn't the Apollo deluge use a water tank to let gravity help out (like city water does in a lot of places)?
Upvote
-1
(2
/
-3)
There's very little head pressure here, and a limited volume of water. the startup demand is so quick that pumps might be starved and cavitate.
Upvote
8
(8
/
0)
When the count repeatedly returned to 40 secs, I had to check that I wasn't streaming a fake YouTube channel that was about to switch to A.I. Elon Musk selling crypto.
Upvote
8
(9
/
-1)
Have you seen more specifics about this design? I assumed they were just cameras with a local connection to the rocket which would rebroadcast the stream, but using actual starlinks should have been obvious.
Upvote
1
(1
/
0)
Upvote
15
(15
/
0)
I didn't think they were allowed to shut down the beach on holiday weekends, does that restriction somehow not apply to the Friday at the start of the long weekend?
Upvote
3
(3
/
0)
Resistance
Wise, Aged Ars Veteran
I agree the argument is silly, it's such a small issue. Where we disagree is if it is an thing at all. Musk is famously deeply involved in the naming of things he's involved with, and known for hidden and subtle meanings. For someone so careful with names and so ostensibly concerned with being perceived as a NAZI this is, at best, an amusing oversight.
It is used by countless companies, except notably rocket companies, the reason is obvious.
Upvote
-12
(1
/
-13)
Would that help with pressure spikes and vibrations?
I think those were the main problems, not feeding fuel to the engines.
Upvote
3
(3
/
0)
Bill Swallow
Ars Centurion
I agree completely, but I would add a third question - Functional on-orbit cryogenic propellant transfer.
Granted, Starship can become operational and do useful work without that, but it still seems like a very long pole in the tent to reach its full potential.
Upvote
5
(5
/
0)
It looks like Fridays are ok. From this article:
https://www.valleycentral.com/news/...-starbase-decide-when-to-close-beaches-roads/
Upvote
18
(18
/
0)
Upvote
-16
(1
/
-17)
The wet dress rehearsal would not actually release the umbilicals, as they would be needed for de-tanking. This would be one of the things that can't get fully tested under launch-like conditions (under load and very cold) until attempting launch for real.
Upvote
18
(18
/
0)
My confidence in the future of Starship is now greater than ever.
However, I come from a long line of whack jobs.
Some of my ancestors believed in the Wright Brothers.
Others, in Alexander Graham Bell.
Some were so whacky as to believe that Henry Ford would get anywhere with his assembly-line buffoonery.
A few were so insane as to fall for the crazy integrated-circuit idea of Jack Kilby and Robert Noyce.
I guess that my nuttiness is genetic.
Upvote
6
(11
/
-5)
fellow human
Ars Praefectus
The thing about being a Nazi is everything you do can be suspected to be because you're a Nazi.
Upvote
-12
(4
/
-16)
Not a rocket engineer but I believe a larger pipe should help even out pressure.
Just quoting what spacex.com says on their article about the changes for Starship V3:
Introducing Starship V3
Upvote
3
(4
/
-1)
NASA and the various contractors built prototypes and test articles to work various problems all through the program and blew up or broke more than a few of them. They had the money, manpower, and freedom to do so, which is why the program moved as fast as it did.
Going from a mockup to a flying vehicle in 5 years, when a good 60-70% of what you're doing is breaking new ground (propulsion cycle, materials, manufacturing, conops), is amazing progress.
Yes, Elon overpromised on timelines. He always has, that's nothing new. His mouth writes checks his engineers aren't ready to cash.
He did it with Falcon 9, he did it with booster landings, he did it with Crew Dragon; all of those systems have met or exceeded expectations. The fact that they took a couple of years longer than initially promised doesn't negate that. No, Starship isn't hauling the mail yet, but for some in this thread (they know who they are) to claim that it's a total failure and will never, ever work because Elon missed his initial deadline is a fallacy of the highest order.
It is beyond unfortunate that Elon's behavior has tainted absolutely everything SpaceX has done; these are incredibly talented, passionate engineers and technicians who have significantly advanced the state of the art in spaceflight and deserve better than the scorn directed at Elon (who absolutely deserves it).
Upvote
17
(19
/
-2)
Resistance
Wise, Aged Ars Veteran
That's the thing about dogwhistles, they are specifically chosen because they could be interpreted as either benign or deliberate. In general, when accused of using a dog whistle or overt symbol, people will react with regret and a promise to avoid using it in the future. Though others will react differently. Few people who aren't bigots want to be perceived as bigots so they will work to avoid looking and acting like a bigot.
The prevalent use of dogwhistles creates a lot of problems.
My favorite example is this 14 word 88 character tweet from the 2021 Canadian election:
To some it was clearly a deliberate nod to the 1488 dogwhistle and the language a reference to this quote:
To others it was a completely benign coincidence.
The reactions to these claims from supporters were either:
The critics are unhinged, I'm going to support more.
The critics are right and I agree with the ideology being presented.
I don't care either way and I'm going to continue supporting.
Dogwhistles exist and are used frequently because they work well.
Upvote
-13
(4
/
-17)
Uh….dude’s been off the rails for a decade or more, unless you see a bunch of fully autonomous Teslas outside your window and know about some Mars colony we don’t.
Upvote
-12
(1
/
-13)
Wasn’t aware he had participated in material way other than money.
He’s not all that smart and is certainly not what anyone would consider an engineer, lol
Upvote
-16
(1
/
-17)
I instantly had to wonder if she is Elon's new baby mama
Upvote
-1
(3
/
-4)
SpaceX specifically said modified Starlink satellites for the last two, rather than modified Starlink mass simulators. On their launch livestream, they also briefly showed what those things (that they jokingly called "Dodger dogs") look like:
- that looks rather more polished that the typical mass simulator from previous flights.
Upvote
5
(5
/
0)
Yep - widening the pipe increases the distance from the "vicosity-film" at the sidewalls; that film is a pretty consistent thickness, primarily related to Reynolds number (i.e., primarily friction) between the sidewall and liquid, and the viscosity of the liquid itself. I have no idea what the viscosity characteristics are for cryogenically cold hydrocarbons (at least they are non-polar), but I'm betting that the characteristics for O2 are pretty whackadoodle, since O2 demonstrates magnetic behaviors when liquified.
Overall, this means, the further you get from the sidewalls the more likely you are to generate high velocity laminar flow, to minimize turbulence and generate a fairly predictable and stable pressure profile across the entire flux region.
Upvote
8
(8
/
0)
Well.. not after the IPO, since it's going to IPO with a LOT of dead weight attached to it.
Upvote
-4
(0
/
-4)
Try reading what I wrote a little more carefully; you kinda missed my point.
He's smart enough; he's taught himself enough about orbital mechanics and rockets to speak somewhat competently, at least to other laymen.
Man has some skills. He's buggier than a shithouse rat and twice as repulsive, he's rotted his brain on ketamine and hero worship, but he does have some technical proficiency. Not the degree to which his admirers would have you believe, but he's not the complete and total moron his detractors would have you believe, either.
Upvote
7
(7
/
0)
They can spin up and precharge the system using pressure reservoirs (compressible gas) which helps them know 1) that the system will push water in some amount of volume ahead of it actually having to do so and 2) the size of the pumps needed move the amount of water required are likely a good bit larger and energy hungry then a set of gas generators.
Upvote
0
(0
/
0)
Upvote
0
(0
/
0)
You are aware 3... comes after 1 and 2, which SpaceX already developed?
Upvote
0
(1
/
-1)