Every time there’s a test of a scramjet, there’s associated overhype about how great it will be for space access. The upcoming X-51 flight is no exception:
Ms. Waldman said in her report that as scramjet technology is developed testers believe that in the near future it could be used to aid warfighters as a weapons delivery system. She said officials believe that in the future the scramjet technology will make space access easier.
“The application really is all about space lift,” Mr. Brink agreed, and said, “This is the one, I think, in the Air Force Research Lab we’re most excited about.”
Mr. Brink pointed out that they currently transport payload into space with the shuttle, which has to carry all of its oxidizers for the propulsion concept. He said the shuttle is a pure rocket system and said if they can incorporate scramjet engine technology into the space lift systems, they wouldn’t have to carry the oxidizers and could carry more payload instead.
Yeah, if there’s any payload left after you count the weight of the engines, which have terrible T/W compared to rockets, and all of the extra drag you incur staying in the atmosphere to collect the oxygen. I’ve discussed this more than once in the past. I’ve never seen a hypersonic airbreathing conceptual vehicle design that was an improvement in performance over a rocket for a space transport, at least if there was any analysis more serious than the above performed on it. Scramjets have plenty of utility for military applications. I wish that people selling the program didn’t always feel the need to oversell it. And if we had a smarter space media, they’d get called on it.
As someone who has a great deal of experience designing fly-by-wire control laws, plus doing the S/W implementation of said control laws, plus having some responsibility for architecting the redundant flight critical H/W, a few thoughts about FBW and redundancy, to clear up some of the statements made above (not directly germane to the original post, but what the hell):
(1) I don’t work for Airbus, nor have I been involved with their aircraft, but Mr. Wright’s characterization of them as “Scarebus” is not warranted. The worst control system design flaw in any modern jetliner was the rudder actuator (a H/W component) in the Boeing 737 that was directly responsible for three horrific crashes – no FBW involved, and much less loss of life than the Airbus crashes resulting from control system mode confusion (which did not happen in service, but in testing). The November 2001 AA crash cannot be attributed to Airbus FBW but to dangerous and clearly wrong piloting technique (search the “Ask the Pilot” column at salon.com for at least one pilot’s view of this crash). I disagree with the Airbus design philosophy for FBW in some areas, but it is not at all clear that a more robust way for the pilot to override the FBW would have prevented the accidents in which it was implicated; you can have problems the other way too – there has been at least one jetliner accident (early ’70s with Eastern, a 727 IIRC) where a member of the flight crew accidentally bumped the control column without realizing it, kicking the plane off of autopilot, and got too low to recover.
(2) Trent and Godzilla – S/W reliability for aerospace vehicles is a very complex subject, and if you haven’t done real work developing real-time safety-critical / flight-critical SW, you aren’t qualified to make statements about it. Maybe you have, but it is not obvious from your posts.
(3) Redundancy – in one respect, adding redundancy makes the probability of “a” failure more likely – the more parts, the more likelihood that one will fail. However, if the redundancy is properly designed and implemented (one of the hardest tasks to do on an aerospace vehicle), the likelihood of a failure that leads to loss of control / loss of vehicle is greatly reduced. The key step is determining the true requirement for PLOC / PLOA, then designing the system (and this has to be a true system analysis and design) to meet that requirement – the level of redundancy will fall out. If you’re truly interested in this topic, see this book: http://www.amazon.com/Complex-System-Reliability-Multi-Channel-Imperfect/dp/0615215920/ref=sr_1_1?ie=UTF8&s=books&qid=1267981708&sr=1-1 The author probably has more experience with FBW and redundant system than anybody else in the industry, and has developed some truly unique approaches to the analysis of said systems.
Typo alert – above post should have said “much MORE loss of life” when discussing the 737 rudder problem.
it doesn’t cost more to maintain an orbiter than it would to replace it.
But that’s not really the question Rand. The question is, could a different expendable be cheaper than some maintained reusable where both can loft the same payload. That question has yet to be answered by any real examples.
Godzilla, for thirty years I’ve watched them try to apply the term engineering to software. It’s the biggest joke on the planet.
SpaceX itself is an example of a company having some of the characteristics of big dumb booster. I can’t find the quote at the moment, but they have said they engineer for cost rather than performance. I think they’ve done phenomenally well in both. No, I’m not suggesting they would ever go for BDB.
> it doesn’t cost more to maintain an orbiter than it would to replace it.
But that’s not really the question Rand.
Huh? First you say a vehicle costs more to maintain than to replace, then you say that’s not the question?
The question is, could a different expendable be cheaper than some maintained reusable where both can loft the same payload. That question has yet to be answered by any real examples.
You’ve already been given several examples. It cost less to maintain the X-15 than to build any expendable that can loft the same payload. It cost less to maintain SpaceShip One than to build any expendable that can loft the same payload. It costs less to maintain the Shuttle orbiter than to build any expendable that can loft the same payload. (The major cost in the Shuttle system is replacing the expendable components, not maintaining the orbiter.)
XCOR, Armadillo, Masten, Unreasonable Rocket all have reusable vehicles. They all cost less to maintain than an equivalent expendable would cost to build.
In aviation, it costs less to maintain a jet fighter than to build a cruise missile.
MfK, that’s a good analysis, but an even bigger reason that we went with expendables during the space race is that they were derived, directly or indirectly, from missiles, which by their very nature are expendable.
SpaceX itself is an example of a company having some of the characteristics of big dumb booster. I can’t find the quote at the moment, but they have said they engineer for cost rather than performance.
What makes you think that is a unique characteristic of Big Dumb Boosters?
SpaceX designed both Falcon stages to be reusable — and as you say, they engineer for cost, not performance.
Recovering the Falcon stages has been more difficult that they expected (not surprising, as I told Tom, search and recovery operations at sea are never easy). The failure to recover the stages — *not* the cost of maintenance — has prevented their reuse.
Elon Musk has stated that future versions of Falcon will evolve to reusable flyback stages in versions, which will be easier to recover. Obviously, he does not believe the maintenance cost of a flyback booster will be more than the cost of building an expendable.
First you say a vehicle costs more to maintain than to replace, then you say that’s not the question?
No Edward, what I said was… “It depends on what you compare.”
What makes you think that is a unique characteristic of Big Dumb Boosters?
Did I say it was unique? But it is certainly a characteristic.
The holy grail is the airliner to orbit but nobody’s made one and some suggest it can never be done (not that I agree.) The argument for BDB is that it can be mass produced cheap. Neither has been successfully done yet. I’m saying I don’t know, but would be supportive of attempts at both.
> googaw Says:
> March 5th, 2010 at 9:54 pm
> There are physical limitations to rockets that we’ve basically already reached. Scramjets
> don’t have these same limitations. The limitations they do have are not well characterized.
> Breakthroughs for example that greatly reduce the dry weight of a scramjet would not,
> AFAIK, violate any law of physics, whereas physics says we can’t greatly reduce the
> propellant per payload from today’s chemical rockets. Thus, it is well worth studying
> scramjets based on potential future benefits they might have for getting stuff and
> people off this planet ==
Potentially, and that’s why about all aero firms have studied them. Biggest cost drivers now are R&D costs for the vehicle divided over the number of flights. Second huge fixed costs for facilities, supply chains etc. So really now theres not much reason to bother with more complex engines – especially where they need complex integration with the airframe. Though if you actually get a market of any size to spread that over servicing costs, and issues relating of the size of the craft might become a problem. A ScramJet, or rocket/turbine combined cycle with ram/scran jet could effectively double the ISP on average from ground to Leo, and most usefully drive the ISP up the highest at start and in the atmosphere. This could lead to a dramatically smaller tougher craft. Which could be cheaper to operate and service.
The scram jets generally weight a couple times as much per pound of thrust as a rocket, but you eliminate a lot of weight of tankage, and weight of ship. So if you 100 ton a take off all rocket craft, with 1 ton of rocket engines, becomes a 50ton take off craft with a half ton of rocket engies, a ton less lox tanks, and 1-2 tons of scramjets. You might have a smaller cheaper to buy and operate craft.
> googaw Says:
> March 6th, 2010 at 6:56 am
> Before I call it a week, somebody has to actually point to something I said that is
> wrong. And yes, I do understand the literature and the bases for launch costs
> (note the plural) much better than Trent or Rand.
Unfortunatly Rand lately is tending toward know it all jerk with personal attacks, rather then bothering to think.
> Godzilla Says:
> March 6th, 2010 at 7:04 am
=
> You would be better off developing reusable, low maintenance, low weight, thermal
> shielding however. That is one of the major maintenance costs of the Shuttle orbiter. ==
Not really The TPS servicing costs about $6M a flight, and L/M and the military’s SHARP TPS systems very light and durable
ultramet (dot) com/thermalprotectionsystem.html
>That and the hypergolic RCS/OMS.==
Yeah those are just flamingly stupid. A complet separate fuel and tankage systems for a highly toxic and corrosive fuel?
>= SSME costs are pretty low, ==
??
Still a couple million a flight each to service.
>== The drop tank and the solids are expensive as well.
Solids yes – the drop tanks not really.
>== IMO one of the main issues with doing Shuttle is that it was perceived as a development
> program for a useable system. STS is more of a prototype than a useable system. ==
It was developed as a production freighter – but NASA was already showing it had lost its edge as a development organization.
>== They should have made it a spiral program where the system was progressively
> optimized until an optimum was reached. However they made it too big. Too expensive
> for an R&D vehicle.
It originally was assumed to be a rough cut that would be upgraded into a more serviceable config. But politically, the waste was too popular to cut.
> David Says:
> March 6th, 2010 at 8:10 am
> BTW, here is the mathematical proof of why scramjets are not useful for getting
> to orbit – ===
>
> Hopefully that is not too much math for everyone. Scramjets can still be used
> in a first stage, of course – but there they lose out to simple jet engine types.
> Please let me know if you spot any errors in this.
One big error you noticed. You don’t need to get all the way into orbit with something, for it to be usefull in getting to orbit. First stages neverget to orbital speed –but they are critical to get to orbit.
😉
> Dave Salt Says:
> March 6th, 2010 at 9:12 am
> These sorts of debates use to interest me until about 20 years ago, when I
> finally realise that the problem of space access is really one of economics
> rather than technology. ==
Very very true
>==
> scramjets look awful because their likely development costs are huge –
> just look at what was ‘invested’ in X-30 before it was cancelled.
But several other successful scramjet craft have flown and none has cost numbers anything like the NASP? NASPs big problem is they wanted it to fly as close to orbital speed as possible on scramjets – rather then using scramjets as effectively as possible in getting to orbit.
> Arizona CJ Says:
> March 6th, 2010 at 1:30 pm
> I was hoping someone would weigh in with comments on the X-30 National Aerospace Plane
> (NASP). Also known as Copper Canyon.
The problem with NASP was it was simplistic. The idea of a lighter craft eliminating almost all the take off weight of Liquid oxygen, allowing a craft that could take off from a runway in a normal airbase and fly back for reuse day after day was extremely interesting to the military. They were looking at having to service a huge fleet of SDI laser battle stations in orbit – and this sounded like it would be very operational. The military had decades of experience operating the turboramjet powered SR-71s, and they proved (for a craft of their vintage pretty decent to maintain and operate. So a next generation scramjet system sounded like it would be a spectacular space shuttle.
Course as you noticed pretty quickly it became a mess. Liquid hydrogen is a terrible fuel, especially for anything flying in the air at high speed. It needs huge bulky heavy tanks (not real helpful if you want a low drag hypersonic hull), heavier engines, etc. Its why liquid hydrogen fuel was droped from consideration in the program that wound up building the SR-71’s instead. So instead of looking at other fuels they tried chilling the hydrogen to the point it started to freeze into slush hydrogen. Which added a whole new mes of issues. Then they found they were wasting so much energy just heating air they needed to cool the skin with liquid hydrogen to recover the lost heat, and add it into the engine for power.
Yeah it was going over the top, but the NASP became a BIG multi agency, multi company, mess – that no one could cancel until the DOD gave up, and NASA tried to redefine it into a x-plane project..
To many cooks, with a common stupid leadership, spoiled the aerospaceplane.
You can – and people have – come up with designs using advanced airbreathers, ram/scramjets etc that look promising for a launch vehicle. The NASP program just got so in love with their first idea they went nuts with it.
>==
> I was, as time wore on, more and more receptive to the theory that the NASP was
> never intended for SSTO, but was instead a development program for a successor
> to the SR-71 or some other military application. =
Na. It was really meant to be a SSTO freighter to launch and service SDI platforms. When they gave up on NASP they turned to industry and asked them what their idea was – and that’s where the DC-X program came from. But by the time DC-X was ready to justify building a full up SSTO craft, the SDI design changed and didn’t need that much capacity – so they dumped it.
> ken anthony Says:
> March 6th, 2010 at 6:18 pm
>> Maintenance does not cost more than building a new vehicle.
> While this may be true 99% of the time, it may not be true in all cases. It
> depends on what you compare. Maintenance cost for the shuttle is enormous
> because of the choices made in its design.==
Nope, the margin costs of a shuttle flight are about $60 million, and the total per launch costs with all overhead added in is about $1.3 billion. Each Ares/Orion launch was projected at $8 billion, and each craft would be a couple hundred million in construction costs per flight.
>Edward Wright Says:
>March 6th, 2010 at 8:43 pm >>
>>Redundancy is a separate issue.
> == In the real world, more parts (greater redundancy) generally reduces failure. ==
In the real world more parts increases the numbers of failure modes, thus increasing odds of failure. More redundancy can lower the odds of failure – if the redundancy isn’t achieved with to much added failure modes from added complexity.
No Edward, what I said was… “It depends on what you compare.”
You may have said that, but the data suggests otherwise. In every apples-to-apples comparison, the expendable system loses. It doesn’t matter what you choose to compare. The only counterexample you offered involved the Space Shuttle and had the disadvantage of being wrong.
The holy grail is the airliner to orbit but nobody’s made one and some suggest it can never be done
Some suggest that Apollo never landed on the Moon. I don’t view what “some suggest” as relevent unless it’s backed up by data or convincing arguments.
The argument for BDB is that it can be mass produced cheap. Neither has been successfully done yet. I’m saying I don’t know
But you didn’t say, “I don’t know.” You said no one knows — “That question has yet to be answered by any real examples.” Once again, the question has been answered.
Many examples of expendable rockets have been built. Some of them have been mass produced. Successfully. None of them have been cheap, in any meaningful sense of the term. The fact that expendable rockets are not cheap strongly suggests that expendable rockets are not cheap.
There are also many examples of reusable vehicles, and in every flight regime where those reusable vehicles operate, they are cheaper than expendables.
No reusable vehicle has flown into orbit, but it’s possible to extrapolate data from one flight regime to another. Aerospace engineers do that all the time. No one had ever built a supercruising stealth fighter prior to the F-22, for example, but engineers were able to extrapolate from existing systems to determine that is was possible to build an F-22 and roughly what it would cost to build one.
The fact that expendable rockets are not cheap strongly suggests that expendable rockets are not cheap.
Cheap is relative and robots might substitute for slave labor but V2s were built by the thousands. Considering the circumstances under which they were built (war tends to focus resource usage) they were cheap. This strongly suggest the opposite of your assertion.
There are also many examples of reusable vehicles, and in every flight regime where those reusable vehicles operate, they are cheaper than expendables.
I agree and it’s strongly suggestive; however, going to orbit chemically may not be the same (nuclear not being politically viable.) The original shuttle design was a two stage fully reusable. It’s too bad we never got to see that in operation.
No reusable vehicle has flown into orbit, but it’s possible to extrapolate data from one flight regime to another. Aerospace engineers do that all the time.
It’s also possible for extrapolation to be wildly wrong. We’re suppose to have more people on the planet than we can feed and pedal cars because the fuel is gone. Didn’t happen.
Look, I’d like to see a fuel and go ship to orbit where anybody with the ticket price can take the ride. I expect we will have many more generations of expendables before that ever happens. I’d like to be wrong.
robots might substitute for slave labor but V2s were built by the thousands. Considering the circumstances under which they were built (war tends to focus resource usage) they were cheap. This strongly suggest the opposite of your assertion.
No, it suggests you don’t know how much V-2s cost.
Each V-2 rocket cost as much as a heavy bomber, but the bomber be used many times and the V-2 could only be used once.
What makes you think V-2s are cheap? The Nazis didn’t build thousands of V-2s because they were cheap. They built V-2s because they thought they were a good way to kill and terrorize people. Don’t expect economic sense from a terrorist.
It’s also possible for extrapolation to be wildly wrong. We’re suppose to have more people on the planet than we can feed and pedal cars because the fuel is gone. Didn’t happen.
Are you really confusing doomsday predictions with engineering models, or are you just arguing for the sake of argument?
Look, I’d like to see a fuel and go ship to orbit where anybody with the ticket price can take the ride. I expect we will have many more generations of expendables before that ever happens.
That might very well be true, but even if it is, it doesn’t mean expendables are cheaper. It’s a function of how foolish we are.
Kelly, I don’t disagree with most of your points on scramjets. That is why I advocate research, not development of scramjets (at least in the context of the long-term goal of cheap access to space — if the military decides in the shorter term that it makes a dandy weapon good for them).
I particularly agree with this:
Biggest cost drivers now are R&D costs for the vehicle divided over the number of flights.
Number of flights is not something we can much control: market demand is what it is. (Beliefs otherwise in the space activist community have led only to much tilting at windmills). The key is cutting R&D costs. To that end having NASA spending billions on gold-plated rockets is quite counterproductive — it drives up the R&D costs rather than shrinking them.
BTW, a very effective way to cut R&D costs in aerospace is to reduce the scale. That is why small X-planes, the Rocket Racing League, the suborbital RLVs, and similar efforts are probably where most of the launch-cost-cutting breakthroughs are going to come from over the next few decades.
Another broader point: there’s usually much more bang for the buck in R&D to increase the effectiveness per kilogram of the machine being than in R&D to lower the cost per kilogram of the launch.
That should be “…of the machine being launched…”
It’s a function of how foolish we are.
Now there’s something we can all agree on. 🙂
Don’t expect economic sense from a terrorist.
These days they’re using a few hundred dollars of explosives to destroy vehicles costing thousands of times more. Considering they don’t value there own lives, using hijacked 747s as bombs was economical astute as well. While we’re using expensive smart bombs to take out single targets. We’ve decimated our human intel in favor of expensive toys (which are good to have in the arsenal, but I believe we don’t have the right mix.)
Terrorists seam to be stretching the buck a lot better than we are.
Just looking at payload, heavy bombers make more sense than V2s; but heavy bombers couldn’t penetrate the fighters and radar as well. Trying to do with bombers what the V2s were doing you would find the V2s were indeed cheap (unless you count the bomber crews as of no value.)
Comparing V2’s to bombers is just as failed an analogy as comparing airliners to expendables… each works in a different environment.
As I said, cheap is a relative term. They built many thousands while being bombed themselves. That example strongly suggests that the potential exists to produce hundreds of LEO rockets today at much lower cost than we currently do.
These days they’re using a few hundred dollars of explosives to destroy vehicles costing thousands of times more. Considering they don’t value there own lives, using hijacked 747s as bombs was economical astute as well.
It cost them a lot more than “a few hundred dollars of explosives.” It cost them their organization, their cause, and in some cases even their country. That is not economically astute by any rational definition of the words.
Just looking at payload, heavy bombers make more sense than V2s; but heavy bombers couldn’t penetrate the fighters and radar as well.
Why do you keep saying nonsense? Heavy bombers managed to penetrate fighters and radar, reach their targets, and return to base about 90% of the time. That’s about 90% better than the V-2.
Trying to do with bombers what the V2s were doing you would find the V2s were indeed cheap (unless you count the bomber crews as of no value.)
They weren’t of no value, but they weren’t of infinite value, either. If they were, the Nazis wouldn’t have let them risk their lives by flying bombers.
Comparing V2’s to bombers is just as failed an analogy as comparing airliners to expendables…
I wasn’t making any “analogy.” Not every comparison is an analogy, and not every analogy is “failed” just because you think it is.
Why don’t you tell your theory about the effectiveness of the V-2 to historians, or to the RAF? Or the British analyst who did the original analysis? He’s still alive and living in the US — his name is Professor Freeman Dyson. I’m sure he’d be interested in hearing how “failed” his analysis was.
As I said, cheap is a relative term. They built many thousands while being bombed themselves. That example strongly suggests that the potential exists to produce hundreds of LEO rockets today at much lower cost than we currently do.
You have a very strange definition of “cheap.” One that has nothing to do with money. The fact that the Nazis built thousands of weapons does not strongly suggest that those weapons were cheap. Or even weakly suggest that. The V-2 was a high-priority war project and the Nazis put lots of money into it. Nations that are at war tend to do that. Choosing to believe otherwise does not make it so.
By the way, the V-2 was not a LEO rocket, either.
As to the quintessential, how cheap would V-2 based ELV’s be question:
http://www.fourmilab.ch/documents/rocketaday.html
A Rocket a Day
Keeps the High Costs Away
by John Walker
September 27, 1993
In early ‘40’s money, after $2 billion in R&D, V-2s were being cranked out for about $13,000 a peace, course what cost $13,000 in 1944 would cost $156,848.89 in 2009, after $24 billion in R&D – and that’s more then enough to make your own commercial fully reusable space shuttle fleet. So that’s a good chunk for a crappy “suborbital delivery system” with a couple hundred miles range.
Walker figured a really heavy rugged system with a 1 ton cargo capacity would be $1300/kg to LEO. Walker was a McDonnell Douglas astronaut, and McDac also worked up numbers for fielding a DC-X based shuttle. In contrast it was only $5 billion in current year money to R-D, certify, and get a production line going building them with 20 ton cargo capacity, and for those kind of flight rates, cost per pound to LEO was expected to be more like $200 a pound, or $400-$500 kg.
1. > googaw Says:
> March 7th, 2010 at 6:19 pm
> Kelly, I don’t disagree with most of your points on scramjets. That
> is why I advocate research, not development of scramjets ==
Agree. If there is anything a NASA should do would be to build a test craft using cutting edge stuff.
>> Biggest cost drivers now are R&D costs for the vehicle
>> divided over the number of flights.
> Number of flights is not something we can much control: market
> demand is what it is. (Beliefs otherwise in the space activist community
> have led only to much tilting at windmills). ==
Generally agree – though looking for bigger existing markets could be helpfull.
😉
>== The key is cutting R&D costs. To that end having NASA spending
> billions on gold-plated rockets is quite counterproductive — it drives
> up the R&D costs rather than shrinking them.
True, and groups like DARPA do R&D much more efficiency, but that’s another question – and really if NASA would at least DO usefull R&D I wouldn’t mind the cost.
> BTW, a very effective way to cut R&D costs in aerospace is to reduce
> the scale. That is why small X-planes, the Rocket Racing League, the
> suborbital RLVs, and similar efforts are probably where most of the
> launch-cost-cutting breakthroughs are going to come from over the next few decades.
Highly debatable. Like with the tiny Orion or Apollo capsules and service modules costing so much more then the big shuttle orbiters to R&D. However there were projects like DC-X which made dramatic advances for trivial amounts of money. If nothing else it would be worth the $5 billion just to see if the full sized DC-3 would have worked rather then about half that amount to not build the X-33.
At the least the rocket racing league folks are focused no cost reductions and serviceability issues.
> Another broader point: there’s usually much more bang for the buck in
> R&D to increase the effectiveness per kilogram of the machine being
> than in R&D to lower the cost per kilogram of the launch.
I don’t know, look at how effective the DC-X program was in eliminating cost per kilo of cargo?
Walker was a McDonnell Douglas astronaut
I don’t think so. At least not that Walker.
> ken anthony Says:
>> Don’t expect economic sense from a terrorist.
> These days they’re using a few hundred dollars of
> explosives to destroy vehicles costing thousands of
> times more. Considering they don’t value there own
> lives, using hijacked 747s as bombs was economical
> astute as well. While we’re using expensive smart
> bombs to take out single targets. We’ve decimated
> our human intel in favor of expensive toys (which are
> good to have in the arsenal, but I believe we don’t
> have the right mix.)
Big agree about human intel, though the economics and judgment —- we spend a fortune on smart bombs because we are trying to minimize collateral for humanitarian and political reasons.
However 9-11 cost them a couple million to pull off – adn the whole point was Bin Laden wanted to show the world teh US could be safely attaccked because even after that the lazy Yankiees wouldn’t fight back.
… a bit of a miss calc there!
Opps your right Rand it was Charles Walker who was the McDonnell Douglas, not John Walker.
Alas, Walker succumbs to the economic fantasy of assuming large flight rates. As Kelly has pointed out the R&D costs are a bigger problem than the marginal costs. The problem is hard and the best solution may be along these lines: (1) Simplify the design so that it only takes a handful of machinists to build and assemble it, analogous to how an amateur airplane kit can be built in a small factory and the plane assembled by one person. (2) use standard and inexpensive tooling. If building your first rocket requires you to build new machine tools or to purchase a multi-million dollar machine, you’ve lost the game.
Since this is hard to do today, rocket research should be directed towards these goals instead of towards fancy new technology that provides only small performance increases but requires special machine tools to build. The best analogy is not mass production, but small-batch production such as yachts, specialty sports cars, and build-it-yourself car and airplane kits (minus emphasis on eeking out better performance).
Alas, Walker succumbs to the economic fantasy of assuming large flight rates. As Kelly has pointed out the R&D costs are a bigger problem than the marginal costs.
Not at high flight rates. Calling it an “economic fantasy” ignores that well, it won’t always be such (assuming the idea of high flight rates ever was a fantasy).
. Calling it an “economic fantasy” ignores that well, it won’t always be such
Yes, and some day we may all be driving electric cars. So what? It would still be economic fantasy to start a business based on a plan to sell a billion electric cars but invest so much in building specialized tooling and factories that we lose money on the first hundred thousand cars. Because ten to one hundred thousand cars is a far more realistic sales target unless you are writing science fiction rather than running an electric car business. It is also economic fantasy to build a rocket that makes money in the extremely improbable scenario of “one per day” but can’t recover the R&D costs on a more normal flight rate of five to ten per year. Such a strategy simply guarantees that development costs remain inflated and thus that launch costs remain high.
Since demand for electric cars is far more likely to change rapidly than launcher demand, given the current anti-oil politics, an even better analogy is aircraft. It would have been economic fantasy for the designers of Concorde to have put such faith in large demand for supersonic flight that they invested vast sums in new tooling and new factories based on the assumption that their faster speeds would substantially raise the overall market demand for airline travel so that they would sell even more airplanes than a standard subsonic airliner like the 737. Instead a rational strategy would have been to design the Concorde to reuse tooling already used for supersonic bombers and subsonic airliners, and to make money on the first dozen sold and then see how market demand shaped up. Indeed, exaggeration of the market demand by Concorde’s planners, although far less than Walker’s exaggeration of the launcher market, did lead to overly high development costs and as a result substantial overall financial losses on Concorde.
Alternatively one could contemplate how to develop a high flight rate vehicle/market/industry for less than a few billion dollars.
I do not see any scramjet vehicle meeting that criteria. Scramjets are perhaps interesting from a pure science perspective, and maybe there are military applications, but they are of no direct interest for launch vehicles – so please take them elsewhere. 🙂
It would still be economic fantasy to start a business based on a plan to sell a billion electric cars but invest so much in building specialized tooling and factories that we lose money on the first hundred thousand cars.
That’s four orders of magnitude off initial demand. Corresponding difference between a “rocket a day” and 5-10 launches a year is less than two orders of magnitude. It might be unrealistic to go for the launch rate that Walker wanted, but it is less unrealistic than the example you gave.
Further, it’s worth noting that this philosophy also dictates where the R&D money goes. More would go into actual launches (and other physical tests of hardware) than into developing complex designs. Some number of those launches would come out of the R&D budget, not just from selling launches. To continue the analogue with the electric car example, a substantial number of cars would be produced solely for the purposes of testing.
Finally, as far as low development costs go, I think that is being probed out by various new space companies. Definitely, there is room for improvement here. There does seem to be a trade off between cheaper development costs and other areas like performance or reliability. Everyone who is trying this approach seems to be doing it on the assumption that higher launch frequency will compensate for the problems of less money spent on development.
More would go into actual launches (and other physical tests of hardware) than into developing complex designs.
A fancier design means we have to do more tests, not less, to be confident that it all works. There is no short cut that lets us avoid testing. What is needed to cut the costs of building test rockets is the same thing that is needed to cut the costs of building small batches of operational rockets: low tooling costs.
It cost them their organization, their cause, and in some cases even their country.
Only because we are a very rich country. Trading a cell phone and some C4 for a tank or APC is a bad trade for us.
By the way, the V-2 was not a LEO rocket, either.
You really do think I’m delusional.
Heavy bombers managed to penetrate fighters and radar, reach their targets, and return to base about 90% of the time.
Over London?
we spend a fortune on smart bombs because we are trying to minimize collateral for humanitarian and political reasons.
My favorite is the concrete bomb with no explosives at all designed to take out a tank and not the guy standing next to it.
This didn’t seem right to me…
Each V-2 rocket cost as much as a heavy bomber
So if…
V-2s were being cranked out for about $13,000 … in 1944 [dollars]
Finding the cost of a heavy bomber was kind of difficult but I found this reference…
Each B-24 cost the US government approximately $297,627 to build.
If these are anywhere close then you could build over 20 V2s for the price of this heavy bomber. That’s a lot cheaper than I thought.
Gee, Ken, did you consider the fact that Boeing may have paid their workers for building B-24s? Unlike the Nazis?
And you overlook that “$2 billion in R&D.”
Yes, you are delusional. Anyone who mistakes nutcases like the Nazis for sources of economic wisdom is delusional. 🙂
Sramjets max out at around M12 after that you need MHD tech etc… they make great kinetic energy missles but not for manned LEO applications. Certainly other airbreather cycles when combined with a rocket do offer potential. As for rlv it seems like a no-brainer to me. ELV was a knee-jerk aboration brought on buy the sputnik, red-scare technology. The US was doing rlv incremental R&D up to the X-15. X-24C would have taken it a step further. But the moon-race diverted all those efforts. I would like to us get back to that type development based around airbreathing rocket propulsion (not SCRAM).
However it seems Space-X is hell bent on going down the big dumb path again. To make it even worse they have encarniated the relic splash-down capsule concept. I see Space-X as the spoiler dooming LEO access to stymied big dumb booster tech for decades to come.
Anyone who mistakes nutcases like the Nazis for sources of economic wisdom is delusional.
My pappy had some sayings…
…a wise man can learn from fools; a fool learns from no one.
…if you see a steaming pile in your path; walk around, trying to kick it out of the way will just get it all over ya.
Edward, it is a joy reading your comments. R&D is a sunk cost. Which you know perfectly well. As for slave labor, I acknowledge that when I said, “and robots might substitute for slave labor” Slave labor is not free, but regardless, how many man hours do we have to add to the $13k?
Edward, you said they cost the same and I took you at your word even though I had my doubts. Then someone else brought up the cost for the V2 and I knew something was off. How will I ever trust you in future Edward now knowing you will bend the truth to win an argument? Do you still assert they cost the same? Let’s not forget to mention that bomber R&D was familiar territory where rockets were a bit of a new thing at the time.
I have not yet begun to be delusional 😉
I see SpaceX as the spoiler dooming LEO access to stymied big dumb booster tech for decades to come.
That’s odd. SpaceX is providing orbital access. Others could do it as well. The beauty of free enterprise.
>googaw Says:
>March 8th, 2010 at 8:55 am
> Alas, Walker succumbs to the economic fantasy of assuming large flight rates. ==
Well actually he was flipping that on its head. He just assumed the gov would bankroll it – then market the launches. So if you just eat the overhead adn upfrount, then start the flights adn market them at margin plus — you could jump start big markets. I’ve sen it work in other industries — not sure how well this would work – but its a interesting idea?
> googaw Says:
> March 8th, 2010 at 10:24 am
> Since demand for electric cars is far more likely to change rapidly
> than launcher demand, ==
Actually electric cars are less likely then fusion reactors to come to market big time any time soon. Dark side of electrics — they can cost $1.50 a mile to operate. Electrics eat batteries.
>==. It would have been economic fantasy for the designers of
> Concorde to have put such faith in large demand for supersonic
> flight that they invested vast sums in new tooling and new factories
> based on the assumption that their faster speeds would substantially
> raise the overall market demand for airline ==
At the time that was a safe bet — problem was it hit the market right when the oil embargo hit. After a couple years they gave up adn stoped production — and then the oil prices plumited adn interestin the planes spiked up — but they weren’t making them.
SERIOUSLY bad timing.
😉
> ken anthony Says:
> March 8th, 2010 at 1:44 pm
> My favorite is the concrete bomb with no explosives at all designed
> to take out a tank and not the guy standing next to it.
Well I think shrapnel might get the guy — at the least hes going to need clean undies.
😉