Sid454 - 24/1/2008 12:14 AMThe real issue is can production be ramped up before the 50 remaining NK-33s are used up?
TrueGrit - 25/1/2008 4:54 PMQuestion would be... What would Taurus II with a Delta II upperstage instead of the Castor be capable of?
Sid454 - 25/1/2008 8:47 PM1. I'd go with a centaur resized for use on the Taurus II that or have spacedev make a hybrid stage if they don't get selected for COTS this would offer more flexibility then the castor allow you to launch live cargo ie people and should have a little higher ISP or the second stage RCS would then be a gimme since it can just use some of the cold N2O gas thats already under pressure.2. Every company likely has a plan B if they can't be a prime contractor they can still e a sub contractor o a winner.3. A related story can Taurus II scale up enough to lift something like dream chaser or even something lighter like the t/space CXV?Though orbital likely has their own solution maybe based off the X34.4. If Rocket dyne really does follow though and shut down the SSME production line those people will be available for aerojet to hire.5. A real irony is the USA may be a better bet then the former soviet union for producing these engines because of the recent experience with the SSME.
TrueGrit - 25/1/2008 3:54 PMQuestion would be... What would Taurus II with a Delta II upperstage instead of the Castor be capable of?
TrueGrit - 26/1/2008 4:08 PM How much less impulse does the Taurus II first stage have in comparision to the Delta II combined first stage and SRMs? It would have to be quite significant...
Actually, the Taurus II first stage has more impulse than both Delta II's first stage/SRM combinations. Here 's the comparison (all numbers vacuum):
A single GEM-40: Thrust: 50.2 t, Burn time: 64 sec, total impulse: 3213 t-sec
Delta II core: Thrust: 107.5 t, Burn time: 265 sec, total impulse: 28487 t-sec
Taurus II: Thrust: 387.8 t, Burn time: 171 sec (approx., assumes 200 t of propellant)
Therefore,
Delta II 73XX core + 3 SRB's total impulse: 38127 t-sec
Delta II 79XX core + 9 SRB's total impulse: 57408 t-sec
Taurus II Stage 1 total impulse: 66313 t-sec
Delta benefits from the additional staging event (two additional events for the 79XX) and the smaller thus lighter fairing. The larger core diameter makes the AJ-10's long nozzle airframe structural penalty (interstage mass) larger on T-II than on D-II, thus favoring the Castor-30. On the other hand, D-II (esp. the 79XX) is a bit draggier than T-II.
T-II with the Castor-30 and ORK is "bottom heavy", as typically LV's are at the beginning of their life cycle. As more performance is required of them, they get bigger and bigger upper stages, and more and more SRB's. Who knows, T-II thirty years from now may look just like a Delta 79XX on steroids!
Delta is an amazing rocket, more so when considering its evolution. Unfortunately, it is at the end of its product cycle life, its components have become (they weren't!) very expensive to manufacture, and requires a complex and expensive to maintain vertical assembly/launch pad complex.
The Delta II core costs about as much in parts and assembly/test labor as the Taurus II stage 1 (well, at least I hope that's how it ends up), yet is provides less than half the impulse. And the price of GEM-40's and other SRB's seems to increase each day we ask.
TrueGrit - 26/1/2008 4:08 PMWonder how much larger the Delta II stage would have to grow to make it equivelent?
edkyle99 - 26/1/2008 1:01 AM QuoteTrueGrit - 25/1/2008 3:54 PM Question would be... What would Taurus II with a Delta II upperstage instead of the Castor be capable of? Less. Quite a bit less. By my figuring, you would loose about one metric ton of LEO payload capability using the Delta II second stage rather than the Castor 30 second stage. - Ed Kyle
TrueGrit - 25/1/2008 3:54 PM Question would be... What would Taurus II with a Delta II upperstage instead of the Castor be capable of?
TrueGrit - 26/1/2008 4:08 PM That much lost is a little surprising?
Here's a very rough Excel-and-Solver calculation (all figures approximate, but the relative difference is roughly correct):
T-II S1 C-30 S2 T-II S1 D-II S2Payload 20521 5621 11823 4873 KgJettison 16400 1400 16400 950 KgFinal 36921 7021 28223 5823 KgPropellant 200000 13500 200000 6000 KgInitial 236921 20521 228223 11823 Kg
Isp (Vac) 331 282 331 319 sDV (Ideal) 6034 2966 6785 2215 m/s
Total DVI Actual Target Actual Target 9000 9000 9000 9000 m/s
As can be seen, a T-II S1/C-30 combination has about 800 Kg more payload to a 9 Km/s Ideal DV trajectory than a T-II/Delta II S2 combination. Actually, the difference is closer to edkyle99's 1 ton number due to the higher structural penalty associated with the long AJ-10 nozzle on the larger (3.9m vs. 2.44m) T-II core diameter.
(could somebody teach me how to either enter a table properly or place a figure in the middle of a text without having to store it on some public URL?... I can design rockets, but I can't format squat on this forum...)
(also, can somebody tell me how to use greek letters on the signature line? I'm getting sick and tired of my pig-greek phonetic spelling)
(triple *sigh*) thanks, marsavian. I knew about the "preformatted text" tag, but somehow, after carefully entering the preformatted text between <pre> and <pre>, I preview the text (pun intended) and someting kills my tags and enters a large number of extraneous and random tags... and reverts the font to proportional... arghhhh!Also, the Rich Text Editor and gree font options don't appear to be available when entering one's signature line...
tnphysics - 27/1/2008 8:59 PM What about a larger and/or bipropellant second stage?
(*sigh*)... using what engine? The D-II Upper Stage (a.k.a. "Delta K") using the AJ-10 is about all the biprop gear you can find in the US today...
Or Atlas I style balloon tanks?
Atlas I balloon tanks were wonderful (the lowest structural mass fraction of any launch vehicle stage EVER), but I'm afraid the art has been lost. I remember seeing a picture in Popular Mechanics of the gigantic lathes at the San Diego Convair plant that were used to turn the Atlas fuselages to the proper thickness... This was 1961 or so; I was 12 (and lusting after rockets)... I guess one could use chem milling today, but I'm afraid we don't have the money and the time to develop that capability...
Jim - 25/1/2008 6:52 AMQuoteSid454 - 24/1/2008 12:14 AMThe real issue is can production be ramped up before the 50 remaining NK-33s are used up?All depends on the flight rate and you are forgetting the 40 that are in the US.45 flights or so, that is many years, 5 minimum
antonioe - 27/1/2008 10:21 PMQuotetnphysics - 27/1/2008 8:59 PM What about a larger and/or bipropellant second stage? (*sigh*)... using what engine? The D-II Upper Stage (a.k.a. "Delta K") using the AJ-10 is about all the biprop gear you can find in the US today...QuoteOr Atlas I style balloon tanks?Atlas I balloon tanks were wonderful (the lowest structural mass fraction of any launch vehicle stage EVER), but I'm afraid the art has been lost. I remember seeing a picture in Popular Mechanics of the gigantic lathes at the San Diego Convair plant that were used to turn the Atlas fuselages to the proper thickness... This was 1961 or so; I was 12 (and lusting after rockets)... I guess one could use chem milling today, but I'm afraid we don't have the money and the time to develop that capability...
antonioe - 27/1/2008 9:21 PMQuotetnphysics - 27/1/2008 8:59 PM What about a larger and/or bipropellant second stage? (*sigh*)... using what engine? The D-II Upper Stage (a.k.a. "Delta K") using the AJ-10 is about all the biprop gear you can find in the US today...QuoteOr Atlas I style balloon tanks?Atlas I balloon tanks were wonderful (the lowest structural mass fraction of any launch vehicle stage EVER), but I'm afraid the art has been lost. I remember seeing a picture in Popular Mechanics of the gigantic lathes at the San Diego Convair plant that were used to turn the Atlas fuselages to the proper thickness... This was 1961 or so; I was 12 (and lusting after rockets)... I guess one could use chem milling today, but I'm afraid we don't have the money and the time to develop that capability...
Sid454 - 27/1/2008 10:51 PM5 years should be more then enough time round up as many of the old SSME assembly line workers as they can hire tool up to ready production and test the new batch of engines..
Sid454 - 27/1/2008 11:19 PMQuoteantonioe - 27/1/2008 9:21 PMQuotetnphysics - 27/1/2008 8:59 PM What about a larger and/or bipropellant second stage? (*sigh*)... using what engine? The D-II Upper Stage (a.k.a. "Delta K") using the AJ-10 is about all the biprop gear you can find in the US today...QuoteOr Atlas I style balloon tanks?Atlas I balloon tanks were wonderful (the lowest structural mass fraction of any launch vehicle stage EVER), but I'm afraid the art has been lost. I remember seeing a picture in Popular Mechanics of the gigantic lathes at the San Diego Convair plant that were used to turn the Atlas fuselages to the proper thickness... This was 1961 or so; I was 12 (and lusting after rockets)... I guess one could use chem milling today, but I'm afraid we don't have the money and the time to develop that capability...The old atlas I balloon tanks did have issues with ground handling and require a jig to support them and the vehicle must be pressurized before moving it and kept pressurized while on the pad.They were very prone to accidental damage while being handled which is partly why they switched to an isogrid .The isogrid being stiffer eliminated an oscillation mode from the vehicle that occurred late in the burn as the first stage tanks emptied.The change also allowed strap on SRBs and heavier upper stages which allowed the payload to grow from 3000lbs to over 22,000lbs today.This is also why spacex went with a hybrid balloon/isogrid tank setup over a pure balloon tank on falcon 1 and falcon 9.Balloon tanks are still used on the centaur high energy upper stage so the art of making the tanks is not lost.
Jim - 28/1/2008 5:39 AM Everyone knows that info. Especially, antonioe, who is Pegasus Designer Dr. Antonio Elias
Jim, I know this will come as a shock to you, but EVEN *I* don't know everything...
By the way, if my memory serves me right, there WAS a difference between the original Atlas I tanks and the latter Atlas and Centaur pressure-stabilized ones, precisely in the direction of increasing its buckling stiffness. I don't know this for sure, but I infer it from a number of data, especially the worse structural mass fractions of the latter units. Can anyone confirm?
tnphysics - 28/1/2008 5:34 PMa new, cheaply developed engine?
tnphysics - 28/1/2008 4:34 PM What about a large (30 tonne) hypergol second stage with multiple AJ-10 engines, or a new, cheaply developed engine a la LM landing engine?
Ouch! You're starting to get to the liftoff thrust limit of the NK-33's... no, the cat's meow would be an RL-10 stage that weighs about the same as the C-30, but at RL-10 Isp's and restartable... and for $29.95, of course... anybody's got P&W's phone number?
Jim - 28/1/2008 8:39 PMYou don't need to give a history lesson or regurgitate what has been said on many threads. Everyone knows that info. Especially, antonioe, who is Pegasus Designer Dr. Antonio Elias
CFE - 28/1/2008 6:36 PM "Taurus II" ... When can we expect Orbital to make a firm commitment to the program?
Please allow me to take a rain check on that one. Things are looking good from a cost, schedule and technical standpoint, but we're far from the hard part of program yet... I promise to inform this forum as soon as I'm able.
For that matter, will Orbital have a better name than "Taurus II" by the time the program is approved?
(Quadruple *SIGH*) I'm afraid Taurus II has become quite cast in concrete... Cygnus and all other names seem to have faded away... at least we will follow a long tradition of misnaming: Titan -> Titan II, Delta II -> Delta IV, Ariane 4 -> Ariane 5...
I assume that the Stage 1 structure will be contracted out, rather than done in-house at Orbital.
Good assumption: Orbital does NOT manufacture flight structures in-house either for our rockets or our spacecraft: for example, the Pegasus wing (and fins) are manufactured by Scaled Composites (Burt also designed the structure: I only gave him the outer mold line, the hook pin interfaces, and the loads). We assemble the fairings from major parts that various houses build to print for us. Ditto for spacecraft parts: main core barrel, structural panels, solar panel substrates, etc. We do all the finishing work, such as applying the TPS to the Pegasus wings, attaching the separation joint and hardware to the fairing parts, and all the clips and pucks to the spacecraft panels.
is there any chance of buying additional NK-33's from RpK at this point in time?
I was unaware that RpK owned any NK-33's.
I'd assume there's plenty of bad blood between Orbital and RpK
Bad assumption. I was at the Long Beach conference last year when Alan L. announced officially that RpK had been sent the "warning letter", and when Randy Brinkely had the amazing courage to participate in the panel he had committed to months before. It takes real guts to do what Randy did. I swear I cried.
Lampyridae - 28/1/2008 10:07 PM I was wondering about your overhead costs for launches - like you say, when customers went telemetry etc. with their side order of booster fries and a lox shake. These must consume a fair whack of what you charge for a launch.
They typically range between $800K to about $1.5M depending on a lot of things: range involved, trajectory and amount of coverage needed (e.g., do you need to rent a P3 from the Navy to "see" spacecraft separation? Also, the first downrange station - for example McMurdo or IOS - is sometimes considered a launch cost, sometimes a spacecraft operations cost).
Does Taurus II make some kind of saving here?
Unfortunately, there is nothing on the Taurus II design that significantly change the range costs one way or another, but the choice of range can. We've had very good luck launching Pegasi and "Minotauri" () from Wallops; the guys (and gals) there are very efficient, work amazingly fast, and they bend over backwards to accomodate any reasonable request. Also, because of our relatively large number of new large rocket developments (5 in 18 years... wow! Fasten your seatbelts :laugh: ), Orbital has become quite efficient in preparing range documentation, flight safety analysis, etc (essentially one team does it for Pegasus, Taurus, the Minotaurs and the large suborbitals, thus spreading the cost and keeping up proficiency. It helps a lot when the range knows and trusts you!!!)
On the other hand, the Taurus II design details (such as lack of SRB's, use of a liquid stage 1, etc.) DO save a bundle in fixed infrastructure cost, especially compared with Delta II, but it can't get to the incredible level of simplicity of Taurus where, a week after a launch, you can't tell there had been a space launch there!
Even if you had flight rates that justified reusability - say weekly flights to a Bigelow hab, then how would you cut down on all those other factors? Some sort of standardised launch telemetry service, for example?
Well, yes, I guess that if we had six flights a year TO THE SAME ORBIT and with similar payloads (e.g., no surprise plutonium-powered RTGs... ) the range costs per flight could be halved.
SpaceX's projected costs seem to be creeping ever upwards - I suppose yours did initially as well. Do you think it's partly because of a growing realisation of all the extra costs associated with a launch?
Well, as I reported elsewhere, we nailed the Pegasus development cost amazingly well ($42M actuals vs. $40M predicted) and we blew the recurring costs ($12M actuals vs, $6M predicted) right at the first flight. We did have some cost increases after that But what we REALLY blew were our 1987 predictions of launch rate: 15/year predicted AVERAGE vs. 38 launches in 18 years actual. Which means we had to charge an even greater price than we thought in order to recoup the $42M (I'm embarassed to admit how late we reached the breakeven point...) We're a lot smarter (and older, too) now; that's why we are designing the Taurus II system to survive on 2-3 flights/year.
I know nothing about SpaceX's costs. All I can say is that, knowing what I learned from Pegasus, Taurus and Minotaur, I never understood the logic behind their predictions of price.
TrueGrit - 28/1/2008 2:42 PM Things don't always make sense until you think it out... I was surprised that the T-II stage 1 has greater than D-II 79XX total impluse and yet if you were to put identical upperstages on it would have less capability.
I don't think that's what edkyle99 meant - he was not comparing a 79XX with a Delta K on top versus a T-II with a Delta K on top. He was comparing a T-II with a Delta K on top with a T-II with a Castor-30 on top!
antonioe - 28/1/2008 9:42 PMQuoteis there any chance of buying additional NK-33's from RpK at this point in time?I was unaware that RpK owned any NK-33's.Quote I'd assume there's plenty of bad blood between Orbital and RpK Bad assumption. I was at the Long Beach conference last year when Alan L. announced officially that RpK had been sent the "warning letter", and when Randy Brinkely had the amazing courage to participate in the panel he had committed to months before. It takes real guts to do what Randy did. I swear I cried.
kevin-rf - 29/1/2008 8:02 AMOnce the Taurus II is proven, is there any chance of it being able to up the flight rate by picking up some of the GPS launches that are now flying on EELV's?
Jim - 29/1/2008 7:39 AM Quotekevin-rf - 29/1/2008 8:02 AM Once the Taurus II is proven, is there any chance of it being able to up the flight rate by picking up some of the GPS launches that are now flying on EELV's? they would have to win a contract from the USAF. Doesn't look like they will be doing that for awhile, since the EELV contracts go for many years
kevin-rf - 29/1/2008 8:02 AM Once the Taurus II is proven, is there any chance of it being able to up the flight rate by picking up some of the GPS launches that are now flying on EELV's?
Jim's probably right - GPS is firmly baselined on EELV. There may be a few USAF new (currently not manifested) missions that may be interested in T-II. Onesies, likely. But the EELV program needs the big "production" runs, like GPS.
Then, there are the six or so Delta II "white tails" that seem unable to find a home because they are threatened by the disappearance of the assembly and launch infrastructure after 2010 (remember, Delta II's are assembled vertically at the pad). Unless something pops out really fast (i.e. for launch during or before 2010) they will go to waste. And they are all potential "heavys".
CFE - 29/1/2008 1:27 AM Looks like I'm eating crow now. I assumed that RpK did have NK-33's in-house for the partly-complete K-1, but that might not be a valid assumption.
My understanding is that they did not buy any engines during their COTS-I effort. In the pre-Rockteplane days, Joe C. used to think that they had some rights to some of the engines in Sacramento from the pre-Kistler bankrupcy days, but Aerojet always contested Joe's statements and I seem to remember than even the Kistler General Counsel did not believe they had a case.
I also thought that ill-will might exist from the failed negotiations between Orbital and RpK earlier in COTS, but apparently that was a bad assumption too.
Well, we disagreed on how to attack the financing problem and a few other things, but I guess it ended up as a gentleman's disagreement. Orbital looked at Kistler a lot in pre-Rocketplane days, but we just could not get the numbers to close.
I've repeated my "LV reusability only starts to pay off beyond 50 flights/year" mantra so many times that you are probably sick of reading it. However, if somebody put a gun to my head and forced me to choose a reusability concept, I think Kistler's is the best I've ever seen. I know and admire Randy, Will, Joe (when he acts as what he is: one of the country's top space engineers...) And I worship the very ground George Muller walks on.
kevin-rf - 29/1/2008 2:02 PMOnce the Taurus II is proven, is there any chance of it being able to up the flight rate by picking up some of the GPS launches that are now flying on EELV's?
antonioe - 29/1/2008 12:34 AMQuoteTrueGrit - 28/1/2008 2:42 PM Things don't always make sense until you think it out... I was surprised that the T-II stage 1 has greater than D-II 79XX total impluse and yet if you were to put identical upperstages on it would have less capability.I don't think that's what edkyle99 meant - he was not comparing a 79XX with a Delta K on top versus a T-II with a Delta K on top. He was comparing a T-II with a Delta K on top with a T-II with a Castor-30 on top!
Skyrocket - 29/1/2008 9:16 AMQuotekevin-rf - 29/1/2008 2:02 PMOnce the Taurus II is proven, is there any chance of it being able to up the flight rate by picking up some of the GPS launches that are now flying on EELV's?No way. The GPS to be launched on EELVs do not have an apogee engine and require the launch vehicle upper stage to put them into the circular GPS-Orbit. As Taurus II does not have a reignitable upper stage as Centaur or the Delta-IV-upper stage, it can not handle these launches (neither can Delta II).
CFE - 28/1/2008 11:27 PM Looks like I'm eating crow now. I assumed that RpK did have NK-33's in-house for the partly-complete K-1, but that might not be a valid assumption. I also thought that ill-will might exist from the failed negotiations between Orbital and RpK earlier in COTS, but apparently that was a bad assumption too.
It wouldn't make sense for Kistler to take possession of the NK-33s, thus removing them from Aerojet, where the engines could have been tested near launch time.
I've repeated my "LV reusability only starts to pay off beyond 50 flights/year" mantra so many times that you are probably sick of reading it.
jongoff - 29/1/2008 2:56 PM And fortunately, people are a much lower development cost payload. I hear they can even make them in third-world countries using completely unskilled labor....
Lemme see... I heard that line some time ago from a certain Bart... no, Bert, no..
On the other hand, I understand that the civil liability lawsuits resulting from the loss of said payloads can sometimes reach settlements in the billion $'s, in spite of the very low replacement costs... :laugh:
antonioe - 29/1/2008 10:49 PMQuotejongoff - 29/1/2008 2:56 PM And fortunately, people are a much lower development cost payload. I hear they can even make them in third-world countries using completely unskilled labor.... Lemme see... I heard that line some time ago from a certain Bart... no, Bert, no..
antonioe - 29/1/2008 1:49 PMQuotejongoff - 29/1/2008 2:56 PM And fortunately, people are a much lower development cost payload. I hear they can even make them in third-world countries using completely unskilled labor.... Lemme see... I heard that line some time ago from a certain Bart... no, Bert, no..
jongoff - 30/1/2008 7:36 AMWhile I agree that there are definite risks, there's no other markets that I can think of that will result in the kind of demand necessary to really change the way space is done. But the challenge is that by definition, getting to that point will require changing the way space is done.~Jon
Jim - 29/1/2008 5:54 PMSPS won't be it either
jongoff - 30/1/2008 3:27 AMEdit: Out of curiosity Jim, can you think of any other markets that could *potentially* provide the level of demand necessary to make an RLV worthwhile?
kevin-rf - 30/1/2008 8:46 AM Another would be a set of LEO birds that provide decent resolution IR coverage every half hour or so for detecting, tracking, and fighting wild fires. If we could only make the birds and place them in orbit cheap enough to actually do it.
kevin-rf - 30/1/2008 8:46 AMHow about a network of radar sats for a world wide air traffic control. You will finally get full coverage over the oceans and areas that have sparse radar coverage due to lack of $$$ and population density. You would need (out of thin air here) some 50ish birds in LEO, and I am sure birds like this would be to heavy for anything other than an individual launch on an EELV class vehicle.If designed right it could double as a world wide ship tracking and weather radar system.
Jim - 30/1/2008 9:04 AMQuotekevin-rf - 30/1/2008 8:46 AM Another would be a set of LEO birds that provide decent resolution IR coverage every half hour or so for detecting, tracking, and fighting wild fires. If we could only make the birds and place them in orbit cheap enough to actually do it.DSP does that already
Lampyridae - 29/1/2008 8:46 PMVirgin Galactic has already collected something like $40 million in ticket sales. SS2 is fully reusable and has a (projected) flight rate of something like 100 per year, with what seems like a rock solid business case....
kevin-rf - 30/1/2008 8:46 AMAnother would be a set of LEO birds that provide decent resolution IR coverage every half hour or so for detecting, tracking, and fighting wild fires. If we could only make the birds and place them in orbit cheap enough to actually do it.
aero313 - 30/1/2008 8:11 AMQuoteLampyridae - 29/1/2008 8:46 PMVirgin Galactic has already collected something like $40 million in ticket sales. SS2 is fully reusable and has a (projected) flight rate of something like 100 per year, with what seems like a rock solid business case....Right, just like the Space Shuttle business case of 50 flights a year for $4.5 MILLION (with an "M") per flight. How did that work out?
BTW, this thread is kinda OT from the title.
jongoff - 30/1/2008 10:31 AM Well, to be fair to Scaled, this is actually their *second* spaceship. They've already gotten some data on what it takes to turn one of these things around ... Plus they have a much simpler system that was designed from the start for operations.
Also, Burt has this nasty habit of not trying to acheive (or, even more importantly, promise!) more than he knows can chew, even if the bites are pretty big. Bad, bad Burt, if you keep acheiving what you promise, you will give us all a bad rep...
tnphysics - 20/2/2008 1:42 PMIt will be drop-launched from an aircraft.
tnphysics - 20/2/2008 3:42 PMIt will be drop-launched from an aircraft.
Patchouli - 20/2/2008 5:48 PM1. Looking at Cynus' payload it appears to be a small vehicle that will fly very often vs a big vehicle that flies twice a year.2. Though if the NK33 can't be mass produced before the supply runs out could another engine replace it though this is a very very tough order.3. Killing SLI was one of the stupidest decisions they made and was undefendable. it's a decision that may cause the US to loose the space race .
Frediiiie - 20/2/2008 12:02 AMEd,Elon Musk in an interview Feb 15http://www.news.com/Elon-Musk-on-rockets%2C-sports-cars%2C-and-solar-power---page-2/2008-11389_3-6230661-2.html?tag=st.numsaid Launch cost for Falcon 1 is about $8M thats after experience of two launch attempts, so I guess he's got a bit of data now.You're right the price is up, but not a great deal.Yet.
I can tell you first hand that there is zero issue with a lack of NK-33 engines. None.
I suspect that we would see Taurus re-engined with Merlins before we saw US manufactured AJ-26-62 engines.
Quote from: Danderman on 08/23/2008 08:06 pmI suspect that we would see Taurus re-engined with Merlins before we saw US manufactured AJ-26-62 engines.No, for many reasons1. Spacex isn't going to help a competitor2. Changing engines would be more costly to OSC3. Changing engines is not a one for one option
...but then SpaceX also has an upper stage engine to offer...
Hey, f=ma (and then you die...)
Quote from: antonioe on 08/25/2008 08:02 pmHey, f=ma (and then you die...) I've been using f=dp/dt totally unaware of my impending doom.
The Thrust-augmented Nozzle (TAN) AKA "afterburning rocket" is one of those ideas that look OK on paper, but the practical implementation negates many of its virtues; let me list just three:
Quote from: Danderman on 08/23/2008 08:06 pmI suspect that we would see Taurus re-engined with Merlins before we saw US manufactured AJ-26-62 engines.This indicates a lack of the fundamental understanding of how the rocket stage and the engine are a matched pair. What would seem like small changes in the engine operation end up having huge impacts on the stage. Often resulting in the need to resize the tanks and pressurization system... This in turn impacts nearly every subsystem in the rocket. Essentially you're creating and needign to qualify a new stage.A good example of this is the NK-33's mixture ratio 2.8:1 which is normal for Russian engines, but quite high for the US where most engines run 2.4:1. Or another is the minimum propellant pressures that must be provided to the engine pumps, minimum NPSH or NPSP. These are fundamental engine design characteristics, and the rocket has to make changes to accommodate the "new" engine.
That's the trade... Do a Atlas II to Atlas III like development? Or restart production of an engine built 35 yrs ago in Russia? There's time for Orbital to make that decision, assuming their successful in the first place. But it will start to come to head soon after first flight.
There's time for Orbital to make that decision, assuming their successful in the first place. But it will start to come to head soon after first flight.
Merlin was first test-fired a year after SpaceX was founded. How hard is it to make a new engine? I'm sure if there's a large demand for the Taurus II and they run out of engines, someone could just make a new one. Couldn't cost more than $200 million, half a billion tops. Might be a good idea to have one on the back-burner to use as a bargaining chip with the Russians.
http://www.space.com/spacenews/spacenews_summary.html#BM_2AEROJET LOOKING TO RESTART PRODUCTION OF NK-33 ENGINE [...] Van Kleeck said [...]"If the test is wildly successful, it could lead to future customers and it could drive the need for production sooner,"
Merlin was first test-fired a year after SpaceX was founded.
Quote from: Robotbeat on 08/30/2009 07:47 pmMerlin was first test-fired a year after SpaceX was founded.Because there was some preliminary work done by TRW.
My main point is that Orbital probably is already looking at what they'd need to do in case the Russians don't play ball. If they aren't, then they are fools because the Russians will use that to their own advantage. Does anyone have something beyond conjecture about if Orbital is looking into their options to avoid vender-lock-in?
http://www.space.com/spacenews/spacenews_summary.html#BM_2AEROJET LOOKING TO RESTART PRODUCTION OF NK-33 ENGINE... At this point, Van Kleeck said talks are concentrated on where the new line would be built, though she said Aerojet would prefer a U.S. production line if a sound business case can be made.....This fall, Aerojet is planning a long-duration, high-power test firing of the NK-33 in Samara, Russia. Scheduled for late September or early October, the test could raise confidence in the engine. ...
2. Do we (America), have any RP1 engines with comparable in ISP, to the NK-33?
We have pretty good hydrogen engines, which work fine even on lower stages without any SRBs.
Staged Combustion (most of the Isp difference), and Oxygen Rich Staged Combustion for rest of it.No. An RD-180US would be.
Quote from: Robotbeat on 08/30/2009 07:47 pmMerlin was first test-fired a year after SpaceX was founded. How hard is it to make a new engine? I'm sure if there's a large demand for the Taurus II and they run out of engines, someone could just make a new one. Couldn't cost more than $200 million, half a billion tops. Might be a good idea to have one on the back-burner to use as a bargaining chip with the Russians.Matching NK-33 performance would be much more difficult than building Merlin. Despite being designed in the 60s, it's still a pretty hot engine.Merlin 1c:T/W 96 (according to wikipedia)ISP 275(sl) 304 (vac)NK-33:T/W 136ISP 295 (sl) 331 (vac)
Quote from: Antares on 08/31/2009 01:28 amStaged Combustion (most of the Isp difference), and Oxygen Rich Staged Combustion for rest of it.No. An RD-180US would be.This is a nit, but I was under the impression that the NK-33 ran a fuel-rich preburner.
I have read (no longer remember where) that NK-33 was designed and manufactured by jet-engine manufacturer Kuznetzov, due to a dispute between Korolev and Glushko over what the N-1 engines should be. No idea if that's true, but interesting, if so.
I can add some insight.The Stennis tests are short duration single-engine PRE-FLIGHT ACCEPTANCE TESTS for the Sacramento-stored engines. The test facility is designed for short duration tests using subcooled LOX and chilled RP.The Samara test will be a 2X duration using the Taurus II thrust profile (perhaps a few percent over) and inlet conditions, using a Samara-stored engine from the same production batch as the Sacramento engines. Quite a test!!!While the Russians will be providing the facility and the engine, and will conduct the test, their customer is Aerojet.Different tests, different purpose, different facilities.
Just verified in various AIAA papers: it's ox-rich. See Closed Cycle Liquid Propellant Rocket Engines, by Kuznetsov in 1993.
Antonio, if not a secret, with whom you work in Samara? After all, Kuznetsov SNTK is almost dead...
... using a Samara-stored engine from the same production batch as the Sacramento engines ...
When Valentyn Petrovych REFUSED to design LOX-kerosene engines for the N-1, S.P. told himself: "hmmm... the hardest part of an engine is the turbopump... let me see, who knows how to design high performance aerospace turbomachinery? AH! Nicolai Dmitriyevich Kuznetsov's OKB-276, who is building the world's biggest turboprop engine (the 15,000 horsepower NK-12 that powered the Tu-95 "Bear").The legend is that S.P. went to Kuznetsov with the request, and when Nicolai Dmitriyevich replied "but I don't know anything about rockets, especially combustion chambers!" S.P. said "you worry about the turbomachinery, I'll worry about the combustion chamber".
Quote from: antonioe on 08/31/2009 08:49 pmWhen Valentyn Petrovych REFUSED to design LOX-kerosene engines for the N-1, S.P. told himself: "hmmm... the hardest part of an engine is the turbopump... let me see, who knows how to design high performance aerospace turbomachinery? AH! Nicolai Dmitriyevich Kuznetsov's OKB-276, who is building the world's biggest turboprop engine (the 15,000 horsepower NK-12 that powered the Tu-95 "Bear").The legend is that S.P. went to Kuznetsov with the request, and when Nicolai Dmitriyevich replied "but I don't know anything about rockets, especially combustion chambers!" S.P. said "you worry about the turbomachinery, I'll worry about the combustion chamber".It wasn't only the USSR where people turned to aircraft engine manufacturers to make rocket engines. The RL10 was made by Pratt and Whitney as a derivative of their work on a LH2-powered turbojet for a secret spyplane.To hear the Pratt guys tell it, rocket engines designed by airplane engine guys tend to weigh more but be much more reliable. I wonder if the same holds true for the Soviets.
I know this might seem like a dumb question and this thread might not be exactly the right place for it, but.... In engine designations like "NK-33" are the letters "NK" used because they are the initials of Nikolai Kuznetsov? Or is that just a coincidence? If it isn't a coincidence, why isn't the RD-180 designated the VG-180?
This fall, Aerojet is planning a long-duration, high-power test firing of the NK-33 in Samara, Russia. Scheduled for late September or early October, the test could raise confidence in the engine. “A successful demonstration will increase the confidence level and allow us to reduce some of the performance margins we’ll be carrying,” Antonio Elias, vice president and general manager of Orbital’s advanced programs group, said Aug. 28. “By performing this ground test, we’ll be able to fly with smaller reserves.”
This "2X duration" bit is just beginning to sink in. Isn't it rather an understatement to say it will, "Allow us to reduce some of the performance margins" for Taurus II? Naively, if the engine could be qualified for run durations twice as long, couldn't it power a stage carrying twice as much propellant mass? Wouldn't that be awesome, particularly for a variant with strap-on solids?
Glushko, after designing the LOX-kerosene RD-107 and 108 used on the Semyorka, "converted" to the religion of storable hypergols as the only way to acheive the launch responsiveness required for an ICBM (at the time, solid ICBM's were pie in the sky). Sergey Pavlovich, on the other hand, thought large quantities of hypergol were for the birds. When Valentyn Petrovych REFUSED to design LOX-kerosene engines for the N-1, S.P. told himself: "hmmm... the hardest part of an engine is the turbopump... let me see, who knows how to design high performance aerospace turbomachinery? AH! Nicolai Dmitriyevich Kuznetsov's OKB-276, who is building the world's biggest turboprop engine (the 15,000 horsepower NK-12 that powered the Tu-95 "Bear").