- Joined
- 21 April 2009
- Messages
- 13,645
- Reaction score
- 7,403

The Secrets of Rocket Design Revealed
I am going to share with you some of the little-known techniques and implications of rocket architectural design. Why big rockets sometimes…

There is no proper international competition in the market at the moment that’s half the problem, so I am not sure where you get that idea from that mystically these people are going to appear. Ariane 6 for a start still doesn’t look that competitive and other players have their own issues.As one with first hand experience of ULA’s monopoly I can explain the difference in circumstances why there is no contradiction. The big difference between the ULA monopoly and the potential SpaceX monopoly is that ULA never was competitive on the international launch market (other than the 1st handful that were sold at a deep discount), they priced their products accordingly. Even if ULA went under tomorrow, SpaceX has enough international competition that there is a price ceiling which never existed for ULA (they never obtained the market share SpaceX has). Second, when I showed up at the EELV SPO 13 years ago, there was no plan to compete services. While I was there we did write the New Entrant’s Certification Guide (which I reviewed) and there are now multiple potential competitors that can/would compete for services should ULA go away, so any SpaceX monopoly would be short lived.That’s unlikely to be the case in both the near and medium term due to the US government wanting to retain a plurality of access to space. Also it has always seemed strange to me that the same people decried ULA’s monopoly in the past now welcome Space X approaching the same position. Nobody should welcome a monopoly in the launch market.
So, the premise of the statement is a bit off since the nature of the industry is a bit different than it was in 2010. Today SpaceX wouldn’t be the type of monopoly ULA became when it formed.
A valid perspective if hardware ready to launch today is considered, but space launch is not a today market. Integration timelines typically run on a 24-36 month timeframe, so there’s a bit of a future horizon built in (plus what doesn’t shift right?). That said, the way to think of this isn’t like a normal consumer good/service market, but rather like an entrepreneur or tech model, where fast followers can have a real advantage. Through that lens there are plenty of startups looking to copy/tweak the SpaceX model, some domestic, some international. That alone keeps a considerable pressure on Elon to keep costs low.There is no proper international competition in the market at the moment that’s half the problem, so I am not sure where you get that idea from that mystically these people are going to appear. Ariane 6 for a start still doesn’t look that competitive and other players have their own issues.
I wonder how many times the Russians have wished they'd just given him some old ICBMs to play with.There is no proper international competition in the market at the moment that’s half the problem, so I am not sure where you get that idea from that mystically these people are going to appear. Ariane 6 for a start still doesn’t look that competitive and other players have their own issues.
My $.02, I’ve lived a bit of this and remember how the ex-McDD/Boeing engineers who didn’t want to leave SoCal for C Springs/Decatur completely blew off the crazy PayPal/electric car guy who’d never get to orbit, much less successfully reuse boosters…
Not really, they were too busy launching them to keep EELV out of the commercial market and then selling ULA RD-180’s for the government launches on everybody’s preferred launcher, Atlas V. At least Vulcan doesn’t use a Russian engine…I wonder how many times the Russians have wished they'd just given him some old ICBMs to play with.![]()
All I need say as regards the lack of international competition now and how hard it will be to establish it is to mention what’s happened to Virgin Orbit.A valid perspective if hardware ready to launch today is considered, but space launch is not a today market. Integration timelines typically run on a 24-36 month timeframe, so there’s a bit of a future horizon built in (plus what doesn’t shift right?). That said, the way to think of this isn’t like a normal consumer good/service market, but rather like an entrepreneur or tech model, where fast followers can have a real advantage. Through that lens there are plenty of startups looking to copy/tweak the SpaceX model, some domestic, some international. That alone keeps a considerable pressure on Elon to keep costs low.There is no proper international competition in the market at the moment that’s half the problem, so I am not sure where you get that idea from that mystically these people are going to appear. Ariane 6 for a start still doesn’t look that competitive and other players have their own issues.
The other bit, which I mentioned, is that there’s now an approved process for new entrants to compete for launch services. This was recently relaxed further so new entrants only have to meet the reference orbits for the missions they wish to compete (when I reviewed they had to be able to meet all reference orbits). That’s a big barrier future competitors won’t have to path find the way SpaceX did, which lowers considerably the barrier to entry.
My $.02, I’ve lived a bit of this and remember how the ex-McDD/Boeing engineers who didn’t want to leave SoCal for C Springs/Decatur completely blew off the crazy PayPal/electric car guy who’d never get to orbit, much less successfully reuse boosters…
Bruno: still confident in a Vulcan launch in May. A little more than halfway through qualification testing of BE-4; likely the pacing item for launch.
Bruno: Vulcan debut "only has about four to five days of launch window each month" due to the Astrobotic lunar payload requirements.
Through the afternoon haze, venting is now visible at SLC-41, indicating that propellant load testing is underway for Vulcan's Centaur upper stage!
Watch LIVE: nsf.live/spacecoast
Booster was a clean repeat of last time. Centaur went well, but this was the first time. There was some learning specific to the ground system. We are tuning up some procedures and software to have that all in place for the WDR.
Did she pass? Anything you need to change on next boosters?
Yes, some minor adjustments on the ground side
Yeah but things have changed. Now they get to compete against Falcon 9.Not really, they were too busy launching them to keep EELV out of the commercial market and then selling ULA RD-180’s for the government launches on everybody’s preferred launcher, Atlas V. At least Vulcan doesn’t use a Russian engine…I wonder how many times the Russians have wished they'd just given him some old ICBMs to play with.![]()
Nothing to do with the president. The military wants more than one launch provider, a decision I am entirely in accordance with. At the moment ULA are the only viable option to provide this alternative launch provider. Most arguments I’ve seen to support an effective monopoly of the market by Space X have supported these statements with mistaken arguments about other launch providers out there at the moment.In a response to one of my previous posts on this topic I was righteously called out for incorrectly claiming that ULA would lose a competition with SpaceX, because as a USG sponsored enterprise ULA will persist as long as the USG wants it. So ULA may well continue to survive for a while on taxpayer dole, but as a left leaning European social democrat tax paying resident alien (so much for no taxation without representation btw) I sure hope Uncle Joe Biden sees the light of multiple Merlins and Raptors burning bright in the not too distant future and makes the right call...
First of all, as you correctly assert, ULA (and Vulcan) aren’t going away anytime soon as Vulcan won 60% of the last 5 year block buy and has 18 launches contracted for Kuiper. The most likely ULA exit would be after that block buy expires several years in the future, by which time there will likely be at least one other medium lift rocket, if not multiple ones IMHO. The likelihood of a SpaceX monopoly is pretty small in my opinion, at least for medium category launchers, which is a very different situation from when I worked EELV 2010-12.Nothing to do with the president. The military wants more than one launch provider, a decision I am entirely in accordance with. At the moment ULA are the only viable option to provide this alternative launch provider. Most arguments I’ve seen to support an effective monopoly of the market by Space X have supported these statements with mistaken arguments about other launch providers out there at the moment.
No comment, I interviewed with them not too long ago...Any idea what's taking Blue Origin so damn long?
NASA's Joel Kearns says at Space Science Week that Intuitive Machines' IM-1 lander is in "very last stages" of integration and test for a June launch. Astrobotic's Peregrine is ready, waiting for call to ship to Florida for integration on Vulcan Centaur.
Keeping you posted: During Qual testing of Centaur V structural article at MSFC, the hardware experienced an anomaly. This is is why we thoroughly & rigorously exercise every possible condition on the ground before flight. Investigation is underway. Vulcan will fly when complete.
Looking at the majority of companies within the space industry today, you can see a common theme in next-generation launch vehicles. This theme is the shift toward either partial or full reusability. While there are a lot of differences in this regard on what is reused and how between each rocket, no matter the size of the launch vehicle, it’s becoming a very popular design choice. This has to do with the fact that reusability, especially in large launch vehicles, provides significant cost and time improvements.
Despite these benefits and the heavy shift within the industry, United Launch Alliance’s next-generation launch vehicle Vulcan is fully expendable. At least, on the surface this rocket is fully expendable, however, in reality, the company has some unique reusability plans for the future. Recent updates from the company and CEO Tory Bruno have shined more light on the future plans and what we can expect.
No matter how reliable Vulcan is, as time goes on, ULA knows that other rockets will begin to gain a significant advantage on the company if they successfully demonstrate reusability. It’s important to consider that a company can offer lower launch costs to customers when reusability is saving them money each mission. Here I will go more in-depth into the recent updates from ULA on Vulcan reuse, SMART technology, busy launch cadence, and more.
Full article here - https://thespacebucket.com/ulas-plan-...
Just wonderful..
United Launch Alliance has been very busy over the last couple of months as they prepare for the first orbital test flight of Vulcan. The recent work has included stacking the rocket, moving it to the pad, and performing some initial testing ahead of the flight readiness firing. Currently scheduled for early May, there is still quite a bit of work left before this rocket takes off.
Unfortunately, the recent explosion of a separate Centaur upper stage at a test stand is not helping. Initially, we learned that an anomaly occurred while testing this stage. Only days ago, more information and images came out that showed the extent of this mishap. While this doesn’t directly affect the first flight of Vulcan, it does bring up some concerns and could add delays.
This comes in addition to more work needed on the main test article and new developments with the payloads. All of which factors into the rocket’s launch date which has already been pushed back a decent bit. Here I will go more in-depth into the recent upper-stage explosion, the first flight of Vulcan, what to expect in the coming weeks, and more.
Hydrogen balloon tanks pushed as far as they will go?
I very highly doubt it. Typically structures, whether pressurized or unpressurized, tend to increase in terms of mass efficiency with increasing scale. For ideal spherical cryogenic tanks designed for the same evaporation rate and internal pressure, the volume will increase by the third power of the radius, but both the structural and insulation masses will only increase by a lower rate closer to the square power, so keep on pushing...Hydrogen balloon tanks pushed as far as they will go?
Since the Centaur is a heritage Lockheed Martin design, this does bring back unhappy memories of the Lockheed Martin X-33 debacle, see https://www.nasaspaceflight.com/2006/01/x-33venturestar-what-really-happened/: https://www.nasaspaceflight.com/2006/01/x-33venturestar-what-really-happened/. Perhaps LM should really leave tank design to the likes of General Dynamics Land Systems... (just kidding, of course.)Hydrogen balloon tanks pushed as far as they will go?
It could be but we don't know the details yet except that it was test-article being pushed to its' limits in which a catastrophic could be anticipated.
Source of H2 leak? Has it been determined if Centaur test article or GSE?
Not yet
How would you go about working out the source? Assuming the blast destroyed most of the evidence to where the source was
Because it was a deflagration (fire) not a detonation, the cylinder is buckled but intact and the dome pieces are large and lying inside the tank. If the leak was in the test article, we’ll find it.
So after you figure the leak out can you redo the test at say Stennis or will you have to wait to rebuild this test stand ?
Got through 14 tests before this one. May not need a full Centaur to finish
A few weeks ago a test of the Vulcan Centaur at the Marshal Space Flight Center ended in a fiery explosion as leaking hydrogen gas found an ignition source. Meanwhile ULA are preparing a Vulcan rocket for flight with a debut 3 weeks from now, while this is not the outcome engineers would hope for I expect that this launch will continue.
ULA’s Vulcan Centaur has been trying to launch for a few years now. Unfortunately for the rocket, a host of different issues and complications have come up during its nearly decade-long development. Right now the rocket is closer than ever, however, it just recently was delayed again with the explosion of a separate upper stage and core testing that still needs to be completed.
Recently ULA CEO Tory Bruno confirmed that the launch scheduled to happen in early May about one week away, will now take off in June or even July. While the rocket is at the pad and the payloads are ready, a final flight readiness firing among other checks is necessary prior. All of which pushing back this maiden flight more than ULA had hoped for.
This being said, the maiden flight of any rocket often runs into delays and gets pushed back quite a bit. Vulcan is no different as it features a bunch of new hardware including two BE-4 engines getting ready to fly for the first time ever. Here I will go more in-depth into the delay of Vulcan’s maiden flight, why this mission is so important, what to expect in the coming weeks, and more.
Full article here - https://thespacebucket.com/the-first-...
In an email update, @astrobotic confirms that the debut launch of Vulcan has slipped due to an ongoing investigation of the Centaur anomaly.
PEREGRINE MISSION ONE UPDATE
Peregrine is assembled and ready for its journey to Florida for integration with our launch vehicle, United Launch Alliance (ULA's Vulcan Centaur. While the Astrobotic team is looking forward to launch, we understand ULA is conducting an investigation following a test article anomaly. The ULA team is no longer targeting a May 4, 2023 launch date and will provide a new date once the investigation is complete. We have confidence they will move through the investigation and Vulcan will fly when it is safe to launch. Follow our social media channels for up-to-the-moment news about when and how to tune in for launch and landing!
Going to assume the conclusion was the centaur anomaly was a test stand failure?
Not yet concluded, but very close now. Been moving fast once we got safe access to the test asset.
I feel that you guys deserve a short time lapse of #VulcanRocket leaving the VIF this morning. Now hard down on the pad for tomorrow’s tanking tests. Enjoy.