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Why are rockets so expensive?

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alexSA:

--- Quote from: pberrett on 11/04/2009 09:06 pm ---
So why do rockets cost so much? Is the the quantity of the fuel used, the high standards required of the rocket casing and motors or is it mostly intellectual property cost?

Can someone provide a breakup of a typical rockets cost (eg an Atlas). How much of that cost is fuel, how much manufacturing costs, how much profit etc? 

--- End quote ---

I see noone has attempted to actually provide a cost component breakdown for a rocket yet. Such a breakdown will always be extremely rough (as prices aren't public and can only be estimated).

One thing is clear however, rocket engines are a large part of any rocket.

Let's take Delta II, the following is a very (very!) rough estimate on components and overall costs for a Delta II launch (numbers several years old):

 - ~60 million USD (probably more) overall costs per Delta II launch
 - thereof ~10 million+ for the first stage RS-27A main engine
 - thereof ~5 million+ for the AJ-10 upper stage engine
 - thereof 9 times Castor 4A/GEM 40/GEM 46 solid rocket motors each ~2.5 million = ~20-25 million total
 - thereof fuel ~0.1 - 0.2 million (so basically not really a factor)
 - rest: structure, tanks, avionics, payload adapter, infrastructure maintenance, interstage, payload fairing, optional upper stage, sensors, electronics (profits)

Again, this is a very rough estimate, people around here will probably be able to refine it.

Patchouli:

--- Quote from: gospacex on 11/05/2009 02:25 pm ---
--- Quote from: pberrett on 11/04/2009 09:06 pm ---Can someone provide a breakup of a typical rockets cost (eg an Atlas). How much of that cost is fuel, how much manufacturing costs, how much profit etc?
--- End quote ---

Apart from technical reasons for rockets being expensive, there are economical and political ones. There are not that many commercial users for LVs. Government launches constitute a big part of all launches. And government programs do not choose LVs based on logic, as you'd expect in ideal world.

Government will preserve and use inefficient and costly designs, like Shuttle, in order to preserve jobs; it will design new inefficient vehicles even if better alternatives already exist ("empire building" syndrome); etc.

This financially starves better, commercially available alternatives, making them fly less often and driving their costs up too.

--- End quote ---

One problem I have with Ares I is it's being pushed as an alternative to EELVs and RLVs for small payloads within NASA .
It would only seem cheap because the HSF budget would be subsidizing it's infrastructure.
Real costs would not be much of an improvement over the shuttle esp for anything that needs to go beyond LEO.
Ares I needs a third stage for that.

mmeijeri:

--- Quote from: sewand on 11/05/2009 03:40 pm ---I just don't think price per KG is going to substantially improve by adding more launches of the current generation of rockets.   The price drivers for commercial airplanes are passenger traffic and freight.    To get a big increase in traffic we need several orders of magnitude improvement in price/KG - and that won't happen with current designs.   

--- End quote ---

Agreed, but I thought I had seen numbers that indicated prices would come down by amounts customers would notice, maybe to levels where EELV could compete with Ariane, though not to a level where orbital tourism would grow dramatically.


--- Quote ---I remember from an old book about a Philip Bono design (called Pegasus/Icarus) that called for a reusable suborbital transport of people and freight on large plug-nozzle VTOVL rockets.  I think that would be the way for the market to grow - suborbital has lower TPS requirements, less life support needs, etc.   Point-to-point delivery anywhere in the world in about 60 minutes would have a market if the price/kg was at all reasonable. 

--- End quote ---

Point-to-point transport would be exciting, but would there be a near-term market for it? There does appear to be a near-term market for suborbital thrill rides.

For orbital applications propellant seems like the most plausible cargo that would allow high flight rates, which are needed in any scheme I know of that could reduce costs by an order of magnitude or more. That's why I'm so strongly opposed to HLV, so strongly in favour of depots and so strongly in favour of starting with proven technology like hypergolic propellant transfer despite the mediocre Isp and toxicity. The frustrating thing is that while propellant would be ideal from a technical point of view, it is hardly ideal from a political point of view because it's not going to happen unless and until the shuttle stack gets out of the way.

Another concept I like is mass produced expendable rockets, as in the Big Dumb Booster concept, though more likely in a small dumb booster form as the one proposed by Microcosm. I had wondered about pressure fed boosters (probably because I vaguely remembered this from reading about BDB/Scorpius), but existing pressure fed engines seemed to have far too little thrust for this to be practical. But it turns out there have been experimental pressure fed engines with thrust as high as 1MN or more. More than enough for a small launcher. And while these were experimental, they were actually very easy to develop. Apparently. And Microcosm makes composite tanks that are light enough to make this feasible for dense propellants.

And there's more you could do to simplify things. Hypergolic engines don't need igniters, which simplifies things and probably reduces both risks and cost, though I don't know by how much. I've also heard hypergolic launchers don't even need escape towers, but I'm not sure if this applies to all hypergolic launchers, or just to hydrazine based systems, which are obviously unattractive.

Another thing would be to use purely storable propellants (i.e. not even LOX) which eliminates boil-off and insulation issues completely. This could also simplify things like airlaunch.

All in all, if you choose a modular system with a hypergolic, storable, nontoxic and dense propellant combination like H2O2 + kerosene + catalyst and a pressure fed, ablatively cooled engine with composite propellant tanks, you would have a very simple, reliable and safe system.

You could also imagine hybrids between RLVs and expendables, with only partial reuse.

Robotbeat:

--- Quote from: Patchouli on 11/05/2009 03:55 pm ---
--- Quote from: meiza on 11/05/2009 02:57 pm ---
One reason is the requirement for low weight - you can't relax quality and replace it with margin. Hence the pressure vessels, thrust structures etc cost some. This is true both for aircraft and rockets.

Another is the high energies involved. IIRC The RD-170 turbopump has a roughly 170 megawatt power. That's one fifth of a big nuke plant, in something the size of a car engine.

--- End quote ---

This is why some expendable approaches such as Scorpius and Otrag try to avoid use of a turbo pump since this is the most expensive part of a rocket engine.
These and some other concepts also try to avoid the munitions mindset in rocket design.
Such as going for that last 10% of performance despite the fact it could drive up the cost a lot more then 10%.
--- End quote ---

On the other hand, Otrag would make for a dang cheap ICBM launcher for a third-world country (like Libya, for instance......). That's actually one of the biggest issues with the "cheap expendable" concepts. Suppose you need twenty launches, and say, with a reusable vehicle it takes 20 launches to recover the initial costs compared to going the cheap expendable concept. Being able to afford one reusable vehicle, you could afford 20 expendables. If this is a dictatorial country, one reusable launch vehicle is not a strategic threat to anyone. But 20 expendable launch vehicles are a strategic threat. Cheap expendables are also cheap ICBMs, so the cheap expendable technology is a proliferation risk more than the reusable technology is.

--- Quote ---Some of the steely eyed missile man mindset might have to be unlearned to get prices lower.

--- End quote ---
Agreed!

Jim:

--- Quote from: alexSA on 11/05/2009 04:00 pm ---

Let's take Delta II, the following is a very (very!) rough estimate on components and overall costs for a Delta II launch (numbers several years old):

 - ~60 million USD (probably more) overall costs per Delta II launch
 - thereof ~10 million+ for the first stage RS-27A main engine
 - thereof ~5 million+ for the AJ-10 upper stage engine
 - thereof 9 times Castor 4A/GEM 40/GEM 46 solid rocket motors each ~2.5 million = ~20-25 million total
 - thereof fuel ~0.1 - 0.2 million (so basically not really a factor)
 - rest: structure, tanks, avionics, payload adapter, infrastructure maintenance, interstage, payload fairing, optional upper stage, sensors, electronics (profits)

Again, this is a very rough estimate, people around here will probably be able to refine it.

--- End quote ---

Try 80-90 million.

The avionics have substantial portion.

Don't forget launch ops labor

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