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Adeldor t1_j9u7eq4 wrote

> ... Bruno said[,] the oxygen pump on one of these engines has consistently produced about 5 percent more oxygen into the engine than expected. This fell outside the bounds of nominal performance but had only been observed in this engine.

> "We've arrived at the conclusion that this is simply likely unit-to-unit variation, ..."

> "Before the end of 2025 we expect to be really at a tempo, which is flying a couple of times a month, every two weeks."

Between the quoted variance and BO's yet-to-be-proved ability to produce motors at the required rate, I remain skeptical they'll be able to reach such a cadence by 2026.


ballthyrm t1_j9u7ft0 wrote

Cool Rocket ! Is the the race for the first methane engine to orbit still on ?


CurtisLeow t1_j9usfhn wrote

This is highly dependent on Blue Origins ramping up production of the BE-4 engine for ULA. The engines were the main reason for the repeated delays in the first launch.

> "We have to ramp up," Bruno said. "Before the end of 2025 we expect to be really at a tempo, which is flying a couple of times a month, every two weeks."

Even SpaceX has never built first stages at that production rate. SpaceX didn't ramp up product that fast for the Falcon 9 either. It first launched in 2010, but didn't achieve a double digit launch rate until 2017, and that was with reusable first stages. The Soyuz had a higher production rate than that at one point, but the Soyuz is a substantially easier to manufacture rocket. The Soyuz doesn't use solid boosters. The Soyuz uses substantially easier to manufacture gas generator rocket engines.

The entire concept of Vulcan doesn't make sense. They're building a difficult to manufacture expendable rocket, with 3 different engines, including a complicated staged combustion engine. Then they're planning to launch it at a rate that only makes sense for a simpler mass produced rocket, or a reusable rocket. In any other industry they would just be shamelessly copying the market leader.


DBDude t1_j9ut6me wrote

I wonder why they had so many problems with that engine, slipping the deadline again and again. Really, it's yet another oxygen-rich staged combustion engine, even simpler than the dual-chamber RD-180 it replaces. The Raptor is doing fine, and it's a much more complicated engine to engineer (full flow staged combustion).


Adeldor t1_j9v0dbc wrote

I can only speculate. Possibilities that come to mind (which might not be popular):

  • Inefficient/interfering management

  • Insufficient expertise among employees

  • Customer "moving the goalposts"

  • A design quirk making realization difficult

I'm sure there are other possibilities.


asssuber t1_j9v5wdd wrote

Raptor isn't doing that fine. You had many failing during starship's fights (not always the engine fault, but still) and 2 failing in the latest static fire. IIRC it also started development before the BE-4 (well before if you count when it was still supposed to burn hydrogen, but not much development was happening then). And let's not talk about deadlines, we all know that in the space industry they are just optimistic targets.

The RD-180 is a Russian engine, they have experience with oxygen-rich stage combustion, not the USA. AFAIK BE-4 will be the first oxygen-rich staged combustion engine made in USA to be flown (if we ignore that a full flow staged combustion engine also has an oxygen-rich side).


tanrgith t1_j9v9smx wrote

The idea that the ULA would be able to pump out 2 full new rockets consistently each month and have enough demand for it in a world where SpaceX can profitable launch mass to orbit for far less seems wildly unrealistic


This_Environment_883 t1_j9vgeaa wrote

When i read their press thing i thought it sounded like something might be up. It went from LET.GO we got the engines to we got lots of and lot more testing to do

BO couldn’t send two PERFECT rocket engines? Like you know this is the most important thing as everyone as talked about ULA being beholden to BO. And delays and many other things.

So this is a huge red flag to me. The fact launchs go from 2 this a year a few more in 24 then every two weeks makes me think ULA is seeing that a year or two or more to get things right. Not a good sign

why ULA went with BO has never really made sense can anyone tell me why?


DBDude t1_j9vjhn5 wrote

They lit 31 engines, a world record. The last time someone tried 30 they blew up four rockets in a row, the second one destroying the launch facility.

>IIRC it also started development before the BE-4

They were kind of playing around with ideas before BE-4, but real design didn't start until around the same time.

>if we ignore that a full flow staged combustion engine also has an oxygen-rich side

We'd have to. It's amazing to me that a modern company absolutely flush with cash is having serious issues designing roughly a methane variant of what's just a dual-chamber version of what was at the time a 25+ year-old engine. Something's been very wrong at BO. I'm just hoping now that Bezos is actively involved they can clean up their act.


valcatosi t1_j9vkopo wrote

This really bugs me. Zhuque-2's methane stage operated nominally and a later unrelated stage failed. That has no bearing on "methane engine to orbit" and only has any possible bearing on "a rocket with some methane in it has a fully nominal mission". If the point is methane fueled to orbit, Vulcan and New Glenn (lol) are not in the running, since their methane stages don't get the vehicles to orbit.


Elliott2 t1_j9vkqww wrote

i just got offered a test stand position with blue..


valcatosi t1_j9vrace wrote

I'm not really sure what the point of tracking "first methalox launch to orbit" is in the first place. Feels like just a No True Scotsman game. I'm excited to see all of these rockets launch but the fuel they use is not a primary reason why I'm excited.


Adeldor t1_j9vs8i5 wrote

Beyond the interesting technical compromises, the only importance it has for me is the fact that until one actually makes it to orbit, it's yet to be proved. Needless to say, it's surely exceedingly unlikely some hidden gotcha making methalox impractical will surface.


digifa t1_j9w6ezy wrote

ULA’s customer’s needs are quite different from SpaceX. They’re able to launch payloads to orbits and velocities that SpaceX does not offer, and the military, NASA, and many private entities already have contracts lined up with them. ULA and SpaceX are both launch providers, however they occupy different markets and there is a lot of demand for both. They aren’t going anywhere anytime soon.


Xeglor-The-Destroyer t1_j9w9z7n wrote

Eh, it took SpaceX several years to scale to that sort of launch cadence. I certainly wouldn't expect Old Space to miraculously reach a flight every other week within a year.

> why ULA went with BO has never really made sense can anyone tell me why?

Aerojet's AR1 engine was way behind in development. In short, they didn't want to design it unless someone else was paying for it and that made development drag out. BO, on the other hand, was building the BE-4 on its own dime regardless of whether someone else was interested in buying them. Aerojet basically has no ambition as a company.


asssuber t1_j9wgqvt wrote

> They lit 31 engines, a world record.

They lit 32 engines, one shut down during the (short) static fire.

> The last time someone tried 30 they blew up four rockets in a row, the second one destroying the launch facility.

N1 is a very low standard to compare against. It's engines could not even be test fired prior to being mounted in the rocket, much less had a chance to do a full static fire like SH. Those were also the first staged combustion engines ever made, oxygen-rich on top. And the failures had more to do with the rocket than the engines themselves.

On the other end a very high standard of reliability is given by SpaceX itself. SpaceX flew Falcon Heavy five times, each firing 27 engines (plus the upper stage one) and it was 100% successful with no Merlin having a problem in any of the flights. 27 is almost the same as 30, the phantasm of N1 was slayed by SpaceX itself already.

Raptor is clearly immature and problematic if you compare it with Merlin, RD-180, Vulcan-2, etc. We have seen it's engine-rich exhaust several times and they are still tweaking the film-cooling for optimal performance, and might have other problems they haven't spoken.

Given ULA's more stringent standards (they aren't expecting to lose/scrap several test vehicles, going through dozens of engines like Spacex. They don't have engine-out capability to shrug off a few bad engines like SH), I do not see BE-4 as being less fine than Raptor.


Decronym t1_j9whvia wrote

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:

|Fewer Letters|More Letters| |-------|---------|---| |AR|Area Ratio (between rocket engine nozzle and bell)| | |Aerojet Rocketdyne| | |Augmented Reality real-time processing| | |Anti-Reflective optical coating| |BE-4|Blue Engine 4 methalox rocket engine, developed by Blue Origin (2018), 2400kN| |BO|Blue Origin (Bezos Rocketry)| |EELV|Evolved Expendable Launch Vehicle| |ILC|Initial Launch Capability| |N1|Raketa Nositel-1, Soviet super-heavy-lift ("Russian Saturn V")| |NSSL|National Security Space Launch, formerly EELV| |RD-180|RD-series Russian-built rocket engine, used in the Atlas V first stage| |SLS|Space Launch System heavy-lift| |ULA|United Launch Alliance (Lockheed/Boeing joint venture)|

|Jargon|Definition| |-------|---------|---| |Raptor|Methane-fueled rocket engine under development by SpaceX| |Starlink|SpaceX's world-wide satellite broadband constellation| |engine-rich|Fuel mixture that includes engine parts on fire| |methalox|Portmanteau: methane fuel, liquid oxygen oxidizer|

^(13 acronyms in this thread; )^(the most compressed thread commented on today)^( has 22 acronyms.)
^([Thread #8612 for this sub, first seen 25th Feb 2023, 01:34]) ^[FAQ] ^([Full list]) ^[Contact] ^([Source code])


Triabolical_ t1_j9wiaed wrote

The big government program is NSSL , and both SpaceX and ULA are certified to do all of their launches, as that was a requirement to bid. And NASA has chosen falcon heavy for Europa clipper, a high energy mission.

What launches is ULA able to do that SpaceX can't?


BabylonDrifter t1_j9ww6vm wrote

Once the vaporware becomes production-ready code, we'll kick ass!


digifa t1_j9x2ep0 wrote

Not much difference, but enough to make a difference. The Atlas has wider flexibility and more options for its fairing load than the Falcon, and both the Atlas and Delta both have very specific high-energy orbits that the Falcon cannot offer—even when it is used fully expendable. And the Delta has a slightly higher payload mass maximum. Other than that, they have their proven track record of decades of reliability.

But I have to admit after reading up on it a bit more extensively, the differences between both companies isn’t as significant as I had previously thought. ULA needs to step up or they’ll be dead in the water very soon.


mfb- t1_j9x2wn6 wrote

Flying every two weeks is 25 launches per year. Let 10 of them be for the US government, then you can go through the Kuiper manifest in 2.5 years. "a couple of times a month" sounds even faster than 2 per month.


mfb- t1_j9x3owe wrote

> and both the Atlas and Delta both have very specific high-energy orbits that the Falcon cannot offer—even when it is used fully expendable

That's why Falcon Heavy exists... besides, Atlas and Delta are retiring, they cannot get new launches anyway.

> Other than that, they have their proven track record of decades of reliability.

The currently active version of Falcon 9, Block 5, has a 149/149 track record. Falcon Heavy is at 5/5. All these launches were made in the last 6 years, which is a much better indication of current performance than launches from 1990.


mfb- t1_j9x4851 wrote

> The Raptor is doing fine

Most landing failures were linked to the engines not starting up properly. The recent static fire was done with 31/33 because two engines had issues. Compared to a landing this is less critical during a launch because of the large redundancy, but they clearly need to work on that for routine flights.


mfb- t1_j9x4nmw wrote

The second stage of Zhuque-2 uses methalox, too.

I think "reaching orbit with a rocket that uses methane in at least one stage" is a somewhat interesting race. After decades of rocketry without methalox we now have several companies/rockets trying to do that within a year or so.


OudeStok t1_j9xv05q wrote

ULA's Vulcan is yesterday's news. It is not re-usable, despite vague plans to try to save the engines by capturing them with helicopters.


OudeStok t1_j9xv8ci wrote

Comparing ULA to SpaceX is not realistic. Vulcan is yesterday's news. It is not re-usable, despite vague plans to try to recapture the engines by helicopters (plans which ULA has scrapped for the time being).


BlakeMW t1_j9y8iul wrote

I remember this ULA infographic "90% Flown Before Initial Launch Capability (ILC)" bragging about how tried and tested all the components are, except your know, the engines at the bottom at 0.


BrangdonJ t1_j9yphih wrote

I see the switch to methane as part of a sea change in the launch industry. Part of the realisation that hydrogen sucks as a first stage fuel, which is significant because NASA in particular were fixated on it for decades (and still are for SLS). Part of the New Space willingness to rethink old assumptions and ways of doing things. The switch is a symptom rather than a cause, but still a sign of the times.


DBDude t1_j9z1jov wrote

My point is that the Soviets mastered this design almost 50 years ago, yet BO is having problems doing it just with a different fuel. Nobody's ever mastered full-flow staged combustion (didn't go beyond testing), yet SpaceX appears further along with that than BE-4, in about the same amount of time. My bet is that it's mostly management issues.

Edit: New news: ULA is having problems qualifying one of the engines for flight because it keeps pumping out too much oxygen. You'd think BO would at least have something like this right before they shipped, but apparently the engines had only minimal testing.

I like SpaceX, but I don't want them being the only cheap, reusable medium+ launch service out there. BO needs to get its act together.