Price (or cost) of rocket engines

[Kansan52]

I am not an engineer. This sight has such a wealth of knowledge and you have seen a small amount in this thread.

One lesson from this sight is the answer is not the engine, not the rocket, and not even the company. It is the service.

First is the mission you need to accomplish. Then who can do it. Generally plan on signing the launch service contract years in advance.

The list of engines earlier and the estimates given should be the start of a nice chart if engines are the only parameter.

[Nilof]

There is no such thing as a fair and reasonable price for an engine, really. Market economics for rocket engines don't really exist, most engines are custom-designed for a particular customer that goes on to be the only customer for that engine. Furthermore, politics play a major part in who can be allowed to make what for whom. The sample size is just too small.

In addition, the sector is in the process of being disrupted by a number of changes such as improvements in manufacturing (such as 3D printing), and in reuse becoming more of a concern for new launch vehicles due to SpaceX and Blue origin which changes requirements.

[Lar]

Merlin good, all others (currently available) bad.  Done.

OK  no, that's not right. Horses for courses. But one could argue that the total package the F9 booster offers is pretty remarkable on a price/performance basis.

I'm not sure what the OP is after either. He or she turned up with a very open ended question and not a lot of motivation other than "for my employer" ... that's what consultants are hired for, but he or she is getting our thoughts for free. Wonder what we get in return other than intersting discussion (which often is "enough" to make it worthwhile)....

[QuantumG]

There is no such thing as a fair and reasonable price for (anything really)

Honestly, people seem to refer to a "fair price" as if it's obvious to everyone else. In a sense, that's what they mean, the price that you'd expect to pay. It's basically sentimentalism. That price feels low, that price feels high, but that price feels just right. If you need a rocket engine you pay what you have to pay for the application you're buying it for. If you can't afford it you try to build your own, and 99% of the time you go out of business.

[Robotbeat]

All I know is the Merlin 1D is a killer engine... If you were pretty good at making lightweight structures (comparable to F9), you could make an expendable SSTO smallsat launcher (500kg?) out of a Merlin 1D first stage. Cost of the engine would be so cheap (if SpaceX charges you, say, half a million) that you could beat the snot out of more other smallsat launchers plus with the added safety of SSTO.

[envy887]

All I know is the Merlin 1D is a killer engine... If you were pretty good at making lightweight structures (comparable to F9), you could make an expendable SSTO smallsat launcher (500kg?) out of a Merlin 1D first stage. Cost of the engine would be so cheap (if SpaceX charges you, say, half a million) that you could beat the snot out of more other smallsat launchers plus with the added safety of SSTO.

I don't think it quite makes it. A Merlin 1D can only lift about 75 tonnes at SL and can only put about 3 tonnes through 9400 m/s. That requires a dry mass fraction under 4% which is much more like ITS than Falcon.

[S.Paulissen]

All I know is the Merlin 1D is a killer engine... If you were pretty good at making lightweight structures (comparable to F9), you could make an expendable SSTO smallsat launcher (500kg?) out of a Merlin 1D first stage. Cost of the engine would be so cheap (if SpaceX charges you, say, half a million) that you could beat the snot out of more other smallsat launchers plus with the added safety of SSTO.

I don't think it quite makes it. A Merlin 1D can only lift about 75 tonnes at SL and can only put about 3 tonnes through 9400 m/s. That requires a dry mass fraction under 4% which is much more like ITS than Falcon.

Elon has already confirmed that the FH side boosters were SSTOs with little to no payload.

[envy887]

All I know is the Merlin 1D is a killer engine... If you were pretty good at making lightweight structures (comparable to F9), you could make an expendable SSTO smallsat launcher (500kg?) out of a Merlin 1D first stage. Cost of the engine would be so cheap (if SpaceX charges you, say, half a million) that you could beat the snot out of more other smallsat launchers plus with the added safety of SSTO.

I don't think it quite makes it. A Merlin 1D can only lift about 75 tonnes at SL and can only put about 3 tonnes through 9400 m/s. That requires a dry mass fraction under 4% which is much more like ITS than Falcon.

Elon has already confirmed that the FH side boosters were SSTOs with little to no payload.

Maybe for the empty booster to a low altitude, low inclination orbit. But a typical reference orbit for small-sat launchers is 500 km sun-synchronous, which is ~600 m/s more demanding. That quickly takes a SSTO payload from zero to negative.

A Falcon-1 SSTO putting up 500 kg would be like a Falcon 9 SSTO putting up 4500 kg. It could be done with 4% dry mass, and to sun-sync with 3% dry mass. But not with Falcon's 4.5 to 5.5% dry mass.

[Robotbeat]

Falcon booster was supposed to get 25:1 mass fraction when optimized, i.e. 4%.

[99miles]

RS-25: around $50M

RS-68: $10 to $20M each (old info ca. 2006) https://forum.nasaspaceflight.com/index.php?topic=2623.0

Suppose I want to try to develop a "fair and reasonable" price for the RS-68 by comparing it to the RS-25 and doing a parametric price analysis based on thrust, or possibly thrust x specific impulse.

Apart from the RS-25's man-rating, what other properties of these two engines would make that analysis misleading?  How could I correct for them?

[Kabloona]

RS-25: around $50M

RS-68: $10 to $20M each (old info ca. 2006) https://forum.nasaspaceflight.com/index.php?topic=2623.0

Suppose I want to try to develop a "fair and reasonable" price for the RS-68 by comparing it to the RS-25 and doing a parametric price analysis based on thrust, or possibly thrust x specific impulse.

Apart from the RS-25's man-rating, what other properties of these two engines would make that analysis misleading?  How could I correct for them?

I'm dubious that you can get any meaningful result from such a parametric analysis. The RS-68 is significantly different from the RS-25 in that it has substantially fewer parts (Wikipedia says something like 80% fewer) and has a fundamentally different nozzle design (channel wall cooling with an ablative nozzle extension, vs brazed tube cooling in the RS-25).

By reducing the parts count and getting away from the labor-intensive process of brazing the nozzle tubes, the RS-68 can be made significantly cheaper than the RS-25. These are major factors in the cost difference that have nothing to do with parametric thrust or ISP comparisons.

Maybe I'm missing the point of what you're trying to do, but the actual reason an RS-25 costs so much more than an RS-68 has to do with the design and manufacturing issues, and just doing a parametric comparison of thrust or ISP ignores those factors.

The way NASA would to do a true "should cost" analysis is to estimate the cost of manhours and materials that go into a typical component (say, a channel wall nozzle vs a brazed tube nozzle) based on their extensive experience with engine design, construction, and procurement. And they would estimate that an RS-25 nozzle "should cost" much more than an RS-68 nozzle with its less labor intensive channel wall cooling and ablative extension. And so on, for each component or subsystem of the engine.

They would then end up with a bottom line "should cost" number for each engine based on its unique design and specifications, and the RS-68 number would likely be significantly less than the RS-25 number. Both numbers would probably be around what envy887 posted above.

So your comparison problem is that you can't "correct" for the differences in design unless you know (to pick just one example) what it "should cost" to build a channel wall nozzle with an ablative extension, as compared to a brazed tube nozzle,and that's a level of knowledge most people on this site, including me, don't have.

[spacenut]

Does anyone know the cost of the BE3U? 

[Davidthefat]

What it costs to make something doesn't mean it's what they sell it for and the R&D costs rolled up into it.

[john smith 19]

Suppose I want to try to develop a "fair and reasonable" price for the RS-68 by comparing it to the RS-25 and doing a parametric price analysis based on thrust, or possibly thrust x specific impulse.

Apart from the RS-25's man-rating, what other properties of these two engines would make that analysis misleading?  How could I correct for them?

Wow, you sound like some new hire whose been set a nearly impossible challenge by their boss.

There are 2 ways to do this. Top down and bottom up. What you're doing is top down. You seem to be trying to draw a line with 2 points only.

You could start by finding a standard Work Breakdown Structure for a rocket engine (AIAA should have something, or NASA STI or DTIC for known cycles) then getting cost estimating data from production engineering handbooks and working through the numbers. Parts counts is a factor, as is touch labor (a USAF general commented an RL10 took more touch labor than a Ferrari). Cost models developed for photocopiers (which deal with part count rather than part mass, which is what most aerospace CER's basically deal with) seemed to be more accurate according to Len Cornier.

What do you want?
What constraints do you have on on propellants?
How many do you need? 1 big engine on the basis that fewer parts --> less to go wrong, or multi engines (like Saturn V first stage) so vehicle does not suffer loss of mission if one engine fails in flight?
What's the chamber pressure?

IIRC there was a cost estimating equation worked out on one of the old sci.space. newsgroups which had been fitted to most of the large engines up to that time. Chamber pressure was a big differentiator (as it tends to be for combustion instability).

Otherwise the question is so open as to be meaningless.

A "fair price" as a mfg is one that lets me sell enough engines often enough to make a decent profit. A fair price to you (as a customer) is one that lets you build your vehicle within its target cost.

[ZChris13]

-snip-

-snip-

John... that post was over two years ago.

[TinkerLaspeyrs]

99Miles
This is a human economics question about uncertain "known" data biased by prior knowledge.You may as well be attempting to price seasonal fashions where the cost of production may not change much but the market accepts the current price out of vanity. Price is influenced by the prime human motives of greed and fear both for suppliers and buyers. This is reduced in a more vertically integrated operation. Where external suppliers are used they have their own amount of greed. So minimum price and maximum profit favors the vertically integrated. Maybe you could try the Delphi method utilizing some of the expansive knowledge of this forums members. Maybe sort of asking for trouble but you could limit responses as the Delphi method suggests, under pain of exclusion for over enthusiastic contributors. Treat them as outliers as the enthusiasm could be a sign of bias.
A good economist is always vague enough to always be right afterwards. Because it all depends.
You really have to define the utility to the customer. If the customer is the rocket manufacturer then the price Kg/orbit is not the same as the price Kg/orbit to the same orbit for a satellite operator if the satellites mass is half the rockets capability.
Y'all have fun now.