Damn, that's one nice engine, and props to whomever guessed they would look at it for SLS.I am seeing conflicting info regarding RL60 vs MB60, is it the same engine and is it a joint development between Mitsubishi and Rocketdyne?Is this more of a thread for L2? Don't want to get anyone in trouble...
Put this on ACES as well? Then using common thrust structure between 5m ACES LOX tank and a 5m LOX tank on EUS(DUUS) starts making a lot of sense.
I have always understood the two to be a single engine, with MB vs RL depending on the company building it at the time. However, in further digging, it looks that MB-60 refers to a joint Mitsubishi-Boeing engine. In addition, I am finding some interesting differences between the engines, particularly in the turbopump design.Well, learn something new every day.
What does the RL in RL-10 or RL-60 stand for. Rocketdyne-[something that begins with an "L"?
RL was a Pratt & Whitney (pre-Rocketdyne) designation for Rocket (Liquid). For example, the RL20 was the immediate precursor to the XLR-129 and an ancestor of P&W's design for the SSME.
@Lobo,I was wondering where this leaves Aerojet Rocketdyne, but I'd be surprised if they end up manufacturing MB-60.Perhaps something more like RD-Amross & their prep of RD-180 (fairly limited, IIUC)? Could involve fitting the US controller, which you'd assume would be the one from J-2x.Cheers, Martin
Interesting.What did "RS" stand for then?
As to where they would be manufactured, Ed or Downix would probably have some good insight there.
Quote from: Lobo on 07/25/2013 04:21 amInteresting.What did "RS" stand for then?Unknown. The convention goes way back in Rocketdyne/NAA history. Maybe something like "rocket system"?
Once again NASA seems intent on outsourcing this project
I'm trying to remember, but I think the higher pressure thrust chamber was to be made in Japan, and the turbopump assembly and nozzle in the US? I read that somewhere.
I thought NASA was supposed to foster U.S. technology, not send money overseas.
Quote from: Lobo on 07/25/2013 05:07 pmAs to where they would be manufactured, Ed or Downix would probably have some good insight there.To me this looks like a Mitsubishi engine with a NASA-contracted engine controller. It fits right into the April DUUS presentation. Two MB-60 engines would power the stage if they were used. Once again NASA seems intent on outsourcing this project beyond U.S. borders. It has outsource the entire Orion Service Module. It has outsourced the core stage dome panels. Now it seems to be planning to kill off RL-10, the best U.S. built upper stage engine. I'm starting to wonder what will happen once the existing SSME inventory runs out. I thought NASA was supposed to foster U.S. technology, not send money overseas. - Ed Kyle
462 seconds is the precise Isp of RL-10B-2, so no. Big, fully expanded nozzles make a difference.
Lots of confusion on the RL-60 vs MB-60. Per a few papers I have read around the web, the RL-60 was a P&W expander engine (around the size of the RL-10) to be built using components from the US, Japan, Europe and Russia. The MB-60 (or MB-XX) program was a joint Boeing Rocketdyne and Mitsubishi project to create an expander bleed engine that could be assembled in either country.
I thought NASA was supposed to foster U.S. technology, not send money overseas. - Ed Kyle
Quote from: edkyle99 on 07/25/2013 05:35 pmI thought NASA was supposed to foster U.S. technology, not send money overseas. - Ed KyleCongress has made it abundantly clear that NASA is supposed to build the SLS with a shrinking agency budget, all other priorities rescinded. Having JAXA pay for this engine may help them meet that goal, assuming all goes well, and the same goes for the other partnerships. If fostering/promoting American technology were at all a concern, programs like Commercial Crew would not be taking it on the chin.
Quote from: simonbp on 07/25/2013 08:54 pm462 seconds is the precise Isp of RL-10B-2, so no. Big, fully expanded nozzles make a difference.But, full flow rather than bleeder?Cheers, Martin
Convince us how the RL-10 is better than the requirements for this RL/MB-60...
IMHO, USAF would be better served with a drop-in replacement for RL-10 (same thrust, Isp, etc) designed from scratch to use modern manufacturing techniques (i.e. like Merlin 1D). RL-10C is a halfway house, but it still requires vast amounts of touch labor (and therefore oversight) and will never be a truly cheap engine.
Quote from: USFdon on 07/24/2013 07:43 pmLots of confusion on the RL-60 vs MB-60. Per a few papers I have read around the web, the RL-60 was a P&W expander engine (around the size of the RL-10) to be built using components from the US, Japan, Europe and Russia. The MB-60 (or MB-XX) program was a joint Boeing Rocketdyne and Mitsubishi project to create an expander bleed engine that could be assembled in either country. This about how I remember it.MB-60 and RL-60 where two different engines by two competing companies, Rocketdyne (owned by Boeing) and Pratt and Whitney.At the beginning of the millennium the market for satellite launches crashed and in 2005 I believe Boeing sold Rocketdyne to Pratt and Whitney.Which of the two companies was ahead was regularly discussed on old newsgroups.Neither engine survived the merger.I believe there was talk of an MB-35 as well.
Programatically, that's probably not the best, as it's never better to continue developing a project at the same time as developing its replacement. It usually leads to the axe falling on the new project as soon as money gets tight.IMHO, USAF would be better served with a drop-in replacement for RL-10 (same thrust, Isp, etc) designed from scratch to use modern manufacturing techniques (i.e. like Merlin 1D). RL-10C is a halfway house, but it still requires vast amounts of touch labor (and therefore oversight) and will never be a truly cheap engine.
Once again NASA seems intent on outsourcing this project beyond U.S. borders. It has outsource the entire Orion Service Module. It has outsourced the core stage dome panels. Now it seems to be planning to kill off RL-10, the best U.S. built upper stage engine. I'm starting to wonder what will happen once the existing SSME inventory runs out. I thought NASA was supposed to foster U.S. technology, not send money overseas.
The resulting engine could be used in multiple launch vehicles, including SLS, Atlas V, Delta IV, Pegasus 2, and possibly others.
Quote from: simonbp 462 seconds is the precise Isp of RL-10B-2, so no. Big, fully expanded nozzles make a difference.RL-10B-2 has a 250:1 nozzle extension. Vinci and potentially RL-60 manage 465s. I thought expander bleed cycle engines have ISPs similar to GG engines, but are capable of higher thrust than open cycle.
Quote from: DGH on 07/25/2013 10:35 pmQuote from: USFdon on 07/24/2013 07:43 pmLots of confusion on the RL-60 vs MB-60. Per a few papers I have read around the web, the RL-60 was a P&W expander engine (around the size of the RL-10) to be built using components from the US, Japan, Europe and Russia. The MB-60 (or MB-XX) program was a joint Boeing Rocketdyne and Mitsubishi project to create an expander bleed engine that could be assembled in either country. This about how I remember it.MB-60 and RL-60 where two different engines by two competing companies, Rocketdyne (owned by Boeing) and Pratt and Whitney.At the beginning of the millennium the market for satellite launches crashed and in 2005 I believe Boeing sold Rocketdyne to Pratt and Whitney.Which of the two companies was ahead was regularly discussed on old newsgroups.Neither engine survived the merger.I believe there was talk of an MB-35 as well.Ahhhh...interesting... That makes more sense. Thanks for the background.Were they two different competing engines for a specific competition? Or were the two very similar engines just a coincidence?
This was/is a joint Mitsubishi Rocketdyne engine.As long as Rocketdyne is still a partner it sounds like a win-win.
Two papers by W.D. Greene at ntrs. - attachedThrottling to a single set point not less than 75%
Quote from: renclod on 07/24/2013 09:35 amTwo papers by W.D. Greene at ntrs. - attachedThrottling to a single set point not less than 75%So, an MB-60 would have just one throttle point at 75% of thrust?Could that be changed? Could it have an adjustable throttle lower? Just thinking this could be a pretty good methalox engine on a lunar lander if it could throttle continuously, as would be needed for a lander.Can RL-10 throttle continuously? Or is that what the CECE project was about. Could a variant of MB-60 running on methalox be [relatively easily] made to throttle such that it could be used for a lander?Be a nice tie in if MB-60 is used for SLS.
Altair was to have four engines (each throttling to 10%, IIRC).I guess a single MB-60 could do similar duty if it throttled to about 16%, but then you have the issue of how to mount it in the structure without creating something massively tall - and Altair had enough issues with tallness.Dual-axis lander might do it, I guess.cheers, Martin
MB-60 would only get height benefit from retracting nozzle if it can retract in flight. RL-10 sure can't.Maybe makes more sense as engine on crasher stage. Maybe methalox or storable prop on the lander.Cheers, Martin
This report has some information about the Air Force's AUSEP program.Space Launch System Advanced DevelopmentOffice, FY 2013 Annual ReportStarts on Page 68
{snip}There are of course many ways to reduce stage height such as using a common bulkhead, have the LOX tank the same diameter as the LH2 tank, use deployable nozzles or have a wider stage. Get creative NASA!
From Page 81 (99 of the pdf). We see that all configurations that get 130 t use a five engine core. The Block 2A with advanced boosters, five engine core, 2xJ-2X upper stage, and 2xRL-10 5 m diameter CPS can only carry cargo. The stack is too high to carry crew.
"Crew: None Cannot stack and rollout DAC1 J-2 based 23000 or 24000 due to VAB limitations (MPCV + 50 ft CPS)"There are of course many ways to reduce stage height such as using a common bulkhead, have the LOX tank the same diameter as the LH2 tank, use deployable nozzles or have a wider stage. Get creative NASA!
Quote from: Steven Pietrobon on 05/05/2014 07:10 am{snip}There are of course many ways to reduce stage height such as using a common bulkhead, have the LOX tank the same diameter as the LH2 tank, use deployable nozzles or have a wider stage. Get creative NASA!Or raise the roof.
There are of course many ways to reduce stage height such as using a common bulkhead, have the LOX tank the same diameter as the LH2 tank, use deployable nozzles or have a wider stage. Get creative NASA!
2.4.2.1 Description. Exquadrum, along with teammates WASK Engineering and ATK,is developing the dual-expander, short-length aerospike (DESLA) upper stage engine concept.
Quote from: Steven Pietrobon on 05/05/2014 07:10 amFrom Page 81 (99 of the pdf). We see that all configurations that get 130 t use a five engine core. The Block 2A with advanced boosters, five engine core, 2xJ-2X upper stage, and 2xRL-10 5 m diameter CPS can only carry cargo. The stack is too high to carry crew.Yea, I noticed that too. There's been a few on the forums who've said definitively that NASA is not even considering anything except the 4-engine core now. And while I'm sure that's the favorite, last I heard NASA was still officially considering 3 options. The Block 1B/2B path, which would retain the 4-engines and not have any more. But also two Block 1A/2A paths, involving a 5-engine core, J2X upper stage, and 5m CPS. (Per an article by Chris last year) This document seems to support that. It's from last year, but it's not that old.
Since this document was published we've heard consistantly that the core will be 4 engines.
That means the balance has to come from liquid hydrocarbon boosters. A five engine core burns through prop too quickly to reach disposal orbit. Thus the next stage must employ lower ISP J-2X to fight gravity losses. The sustainers are not optimally employed this way. A 4 engine core burns sustainers to disposal orbit. All US engines are then for Earth departure only and thus have better ISP than J-2X.
The document is over 16 months old.
It uses the term DUUS rather than EUS. It is out of date.
In Fig. 70 the Block IIB is shown as achieving 130 mt with a 5 engine core, a DUUS, and any advanced booster, be that solid or liquid. Now we know that the liquids are far more capable than the solids. Steven, your own calculations seem to fit pretty well with this schematic. Since this document was published we've heard consistantly that the core will be 4 engines. That means the balance has to come from liquid hydrocarbon boosters. A five engine core burns through prop too quickly to reach disposal orbit. Thus the next stage must employ lower ISP J-2X to fight gravity losses. The sustainers are not optimally employed this way. A 4 engine core burns sustainers to disposal orbit. All US engines are then for Earth departure only and thus have better ISP than J-2X.
By the way, its nonsense to talk about the core burning propellant too quickly. In fact, the quicker it burns the lower the gravity losses during the core burn, which means the greater the performance that can be achieved. Now, depending on the thrust of the upper stage, there will be a certain size for the upper stage that will give you best performance. However, once a certain level of thrust is reached for the upper stage, which depends on the core and booster configuration, performance gains can no longer be achieved (in fact performance will decrease due to the extra mass of the engines).
I'm just glad that they're already bending metal on SLS. That will stop the thing bloating into a remake of the 10m-diameter core, 7 x RS-86 'Godzilla rocket' that was the final configuration of Ares-V before it imploded.
Quote from: Ben the Space Brit on 05/06/2014 11:08 amI'm just glad that they're already bending metal on SLS. That will stop the thing bloating into a remake of the 10m-diameter core, 7 x RS-86 'Godzilla rocket' that was the final configuration of Ares-V before it imploded.I think Ares V had switched back to RS-25E's in it's final version before it got the Axe. I think that's what Direct 3.0 switching from RS-68 to RS-25E was all about.
But if you burn 5 or 6 engines, you are going to burn through the prop more quickly, unless you throttle way down, and why do that?
Sure, you can fly at higher acceleration and G load, but isn't there a g-load max of about 3G for Orion?
You also have MaxQ issues at high acceleration.
This means 4 engines running nominally, 5 to 6 engines throttled down, or 5 to 6 engines running nominally with 5 segment solids.
Sure a LUS can make up the slack, but that means the second stage is still fighting gravity losses. That means more raw thrust is needed. That means J-2X.
And besides, why would you want to throw away 5 or 6 high priced sustainers before they finish a job they're capable of doing?
QuoteAnd besides, why would you want to throw away 5 or 6 high priced sustainers before they finish a job they're capable of doing?Well, that's part of the price versus performance tradeoff. In the configurations I've examined, a six engined core with RSRMV boosters and 2xJ-2X does come out in front. I've yet to examine the Block 2B configurations.
Of course the easiest solution would be for all the rocket scientists in congress to decide that 120mt is plenty of payload.
The RS-25 is a sexy sustainer engine designed for great performance both at sea level and in vacuum and was designed for reuse. And it's not optimally utilized in Steve's concept. An RS-68 would be a better engine for Steve's concept. Lower cost, higher thrust, and they wouldn't be burning long enough for their lower ISP vs. RS-25 to be a detriment.
RS-25 is a sexy sustainer engine
Agreed! But are we discussing SLS missions beyond the first four? I'm assuming yes, in which case we should focus on RS-25E.
One major difference just has to be transitioning the main combustion chamber manufacturing process to HIP (Hot Isostatic Pressure) bonding. It will share this process with J-2X, RS-68, and (the topic of this thread) MB-60. Check out the attached image showing RS-25E modifications. (Wish I had a higher resolution version!) It shows increased commonality with RS-68 in other ways too.HIP bonding will let MB-60 have a long combustion chamber, which combined with its open cycle will allow really high chamber pressure; see the third attached image. The latter two are both from the most excellent paper also attached. It's from 2008, but in 2013 William Sack (the first-listed author) was still at Rocketdyne in Canoga Park doing Bantam engine development.
Didn't the MB-60 get renamed as the MARC-60 (Mitsubishi Aerojet Rocketdyne Collaboration - 60 klbf engine)?
Quote from: AnalogMan on 05/08/2014 05:24 pmDidn't the MB-60 get renamed as the MARC-60 (Mitsubishi Aerojet Rocketdyne Collaboration - 60 klbf engine)?http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003115.pdf
Wouldn't it have to be built by AJR in order to share facilities as you describe?
why NASA's stalking about MB-60 and not RL-60 for EUS?
Quote from: TomH on 05/08/2014 09:19 pmhttp://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003115.pdfI had this in mind as well:http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003113.pdf
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003115.pdf
Quote from: Lobo on 05/08/2014 05:00 pmWouldn't it have to be built by AJR in order to share facilities as you describe? I think the HIP commonality has advantages even if the process takes place at multiple different facilities. That's because it allows the engine programs to share expertise. The same people can monitor the manufacturing and quality assurance processes without having to understand what goes on (and what goes wrong) in multiple different types of combustion chambers.Quotewhy NASA's stalking about MB-60 and not RL-60 for EUS?Apparently the history concerns are over-taken by events. The MARC-60 name says it all.Quote from: AnalogMan on 05/08/2014 09:40 pmQuote from: TomH on 05/08/2014 09:19 pmhttp://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003115.pdfI had this in mind as well:http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003113.pdfFrom the second of those I've taken two images. The "SLS Post Block 1" image shows lots of performance data points; enough to make pretty solid guesses about their assumed stage masses, etc. (I notice they daren't actually mention "Trans Lunar", using "Earth Escape" as a proxy for that. Sigh.)The second image shows a nice break down of the MARC-60 components.
Quote from: TomH on 05/08/2014 09:19 pmQuote from: AnalogMan on 05/08/2014 05:24 pmDidn't the MB-60 get renamed as the MARC-60 (Mitsubishi Aerojet Rocketdyne Collaboration - 60 klbf engine)?http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003115.pdfI had this in mind as well:http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003113.pdf
I had this in mind as well:http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003113.pdf
Very interesting. I wonder if this potential path is looking more likely than the four RL-10 path? Or the other way around, at this point? I thought the RL-10 version was the more likely because it would use existing engines...but perhaps not. ...
Quote from: AnalogMan on 05/08/2014 09:40 pmI had this in mind as well:http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140003113.pdfQuote from: Lobo on 05/09/2014 10:47 pmVery interesting. I wonder if this potential path is looking more likely than the four RL-10 path? Or the other way around, at this point? I thought the RL-10 version was the more likely because it would use existing engines...but perhaps not. ...Question; Aren't these engines too small for the EUS?Using Isp*g = exhaust V, Thrust(N)/exhaust V = Fuel rate, and the life expectancy of the engines I don't see how the configurations shown can go through the 130,000kg or 285,000lb of propellant carried by the EUS.Did I fat-finger my calculator, because I show an MB-60 only drinking 47,158kg in its 800s "Continuous Firing Duration". That's a minimum of 3 engines and no engine-out.If the RL10C can match the RL10B's 1,125s burn it'll only drink 27,211kg. That's five engines and no engine-out.As a bit of an aside; what is the continuos firing duration of the RL10B? I have my own SLS design (as I'm sure many here do) and was wondering if it'll handle a 1,500s constant burn. Of note; The RL10B and MB-60 have 3,5000s life expectancy while the RL10C is 2,000s. Any errors here?
I don't believe EUS is in place to extend LEO payload.It's expected to perform a partial burn to LEO, then a later injection burn.800s-in-one-go may be fine for ascent, if it can do another long burn for injection.cheers, Martin
Quote from: MP99 on 07/01/2014 09:41 pmI don't believe EUS is in place to extend LEO payload.It's expected to perform a partial burn to LEO, then a later injection burn.800s-in-one-go may be fine for ascent, if it can do another long burn for injection.cheers, MartinRegardless of the mission, I was simply pointing out an upper with 2x MB-60s or 4x RL10s cannot consume the EUS's 130mt of propellant in one burn. They would have to layover in LEO before injection, as you mentioned, or coast after the initial burn before refiring.Using a single J-2X would consume all the propellant in one burn to throw the same payload BEO. By my calcs, it can drink about 161mt in one 540sec firing at 100% thrust or the 130mt proposed for the EUS at 81% thrust. If two burns are used, a single J-2X can power a larger upper constructed of one 6.7m barrel section with common bulkhead (~ 215mt propellant) for increased performance.