A letter to JAXA , the Japanese Space Agency:
-----------------------------------------------------------------------------------------
Hello. I saw your IAF reports on the H-II and proposed H-III launchers. I
thought you might be interested in the letter to the ESA copied below. The key
question is one of cost. I looked up references on the H-II rocket since I
remembered it was hydrogen-fueled to see if it could be SSTO. I was surprised
to see that JAXA in upgrading the H-IIA to the H-IIB, that they converted the
single engine on the first stage to two-engines. Contrary to the ESA, they did
this to save on costs rather than developing a whole new, larger engine:
Rocketing to the future.
http://www.gov-online.go.jp/pdf/hlj_ar/vol_0027e/05-07.pdf
Mitsubishi Heavy To Invest In Next-Generation Rocket.
by Staff Writers
Tokyo, Japan (AFX) Jun 14, 2006
http://www.spacedaily.com/reports/Mitsubishi_Heavy_To_Invest_In_Next_Generation_Rocket.html
The development cost for the conversion was 27 billion yen. But 5 billion yen
of this was paid for by Mitsubishi Heavy Industries as prime contractor as
described in the second article. Note also that this 5 billion yen cost
involved increasing the width of the tanks, which wouldn't be needed in the
Ariane 5 case. It is known that increasing the width of the tanks involves a
significant cost increase. Then we might estimate the cost as 22 billion yen,
or $194 million by the exchange rate used in the second article without this
tank width change. This is about what the ESA gave ArianeSpace last year as a
subsidy.
Note also JAXA was using the opposite of the financing ratio suggested by the
SpaceX success and NASA's commercial crew program success, with most of the
cost being paid for by the government and only a fraction being paid for by
private financing.
Following the SpaceX model of the majority of the cost being privately
financed, we might expect the cost to be cut by a factor of 5 to 10, so to
only $20 to $40 million for the conversion in the Ariane 5 case.
I was interested to see in one of your IAF reports you discussed the
possibility of manned launchers. I see also that you intend to make the H-III
be all liquid fueled. Solid-rocket boosters are problematical for manned
launchers because they can not be shut down. Perhaps you intend to use the
H-III for the purpose in that future time frame when it comes into use.
However, the H-IIB core stage can be a SSTO manned launcher in the current
time frame with small modifications. First the H-II core is not as well weight
optimized as the Ariane 5 core. You can improve that by using common bulkhead
design as used by the Ariane. Note this is a well understood lightweighting
method at this point, having been used back in the 1960's on the Apollo
cryogenic upper stages. Also, SpaceX has used it very effectively to give the
Falcon 9 first stage a 20 to 1 mass ratio.
You could also use aluminum-lithium alloy for the H-IIB core. This would cut
an additional 25% off the dry mass of the structure aside from the engines.
This would then give your stage an advantage over the Ariane 5 core since it
also does not currently use aluminum-lithium.
These structural changes are relatively low cost when you already have the
tooling in place for a certain diameter tank. You still though would have to
decrease the propellant load to lift off with only the two engines on the
stage without the side boosters. You can just fill the tanks partially to say
158 mT load, as used for example on the original version of the Ariane 5 core.
It would not cost too much to also cut down the length of the tanks
specifically for the 158 mT load. Lengthening or shortening tank size is not
too expensive as long as you use the same tooling for the same tank diameter.
However, you might also choose to add a third engine onto the core instead of
reducing the propellant load. This probably can be done for comparably low
cost or even less than adding the second one since you don't have the extra
expense of re-tooling for wider tank size.
In short JAXA, can in a short time frame join the group of manned space
flight agencies and at relatively low cost. Also at being the first to
demonstrate a SSTO vehicle JAXA will have accomplished a technical feat in
importance perhaps to rival Robert Goddards first flights with liquid-fueled
rockets.
The ESA already has the lightweight stages and moderately high efficiency
engines to do it. All they need to do is make the politically controlled
decision to add on a second engine to the Ariane 5 core stage. JAXA has the
advantage though in having already added on the second engine, and having more
efficient engines.
The only question now is who will be first to make the quantum leap to SSTO
launchers.
Bob Clark
==========================================================================
Hello. I was interested to read your report, "
(title deleted)"
from July 2011. On page 65 it states:
"The HHSC appears as the most promising launch concept:
– The current design clearly shows the advantages of a single High Thrust
Engine approach yielding less costly propulsion systems."
Other reports I read also suggest producing a staged combustion engine at
about twice the thrust of the Vulcain. This would be a large engine at about
the thrust of the space shuttle main engines(SSME) using also the complex and
expensive staged combustion cycle of the SSME. The SSME of course was quite an
expensive development process for the U.S. How convenient for EADS Astrium and
the other Ariane 5 contractors that the recommended format for the NGL is the
most expensive one!
The idea that this would be a less expensive proposal than using just two or
three Vulcains on the Ariane 5 core stage is highly dubious. In your report
and in other reports I've seen this claim is simply stated without given any
comparison to the multi-engine Vulcain case. This in itself is highly
questionable. I have to wonder why the multi-Vulcain approach among all those
various other ones that are considered is not even evaluated.
Your report stated the single engine concept has proven to be less costly.
Really? With ArianeSpace requiring a 100 million Euro subsidy every year,
without which it would go bankrupt?? Every other space agency in the world,
the U.S., Russia, China, India, has found it cost effective to use
multi-engine stages. It is highly dubious that the ESA has discovered a great
cost saving approach in always using a single engine that no other space
agency grasps, yet at the same time ArianeSpace has to be propped up by
megamillions every year because this approach has not proven to be cost
effective.
I've seen in other reports an attempt to compare this EADS Astrium suggestion
(I call it that because it appears that what's most beneficial to EADS Astrium
is what's most beneficial to the ESA) to the Delta-IV model. That argument
does not hold water either. The Delta-IV could have been launched using two
SSME's. However, the SSME is a quite expensive engine meant to be reusable
with high thrust using the most expensive cycle in staged combustion. The U.S.
developed the RS-68 for the Delta-IV to get an expendable engine with fewer
parts and using the simpler and cheaper gas generator cycle, the same cycle
the Vulcain uses. It is also important to note in regards to cost it is only 1
and 1/2 times the thrust of the SSME, not twice the thrust, which also saved
on cost.
But with the suggestion to develop a staged combustion engine at twice the
thrust of the Vulcain, the ESA is reversing this logic. Because this engine
will be using the most expensive combustion cycle while having twice the
thrust of the Vulcain it very likely will cost more than two Vulcains, *plus*
you have added on that very large development cost for this large engine.
Another argument made for the large, high performance engine is that it gives
options in the size of the payloads launched. For instance, the cores could be
combined a la the Delta Heavy. However, the multi-engine Ariane also has this
capability. In fact, as a single stage it could launch small payloads also,
giving ArianeSpace another market for launches. I have also done a preliminary
calculation that two such cores with the usual Ariane 5 upper stage could
launch ca. 16 mT. And with cross-feed fueling, which can increase payload
about 25%, you could get the 20 mT capability of the current Ariane 5.
An additional big problem with the large, expensive single engine approach is
that it is expected to come into use in the 2020 to 2025 time frame. The
multi-Vulcain approach on the other hand probably could be implemented within
2 to 3 years. I would have no objection to the larger, higher performance
engine being used at that later time for a *larger* stage as long as for *now*
the multi-Vulcain approach is used.
It might be objected the ESA could not afford both. But SpaceX has shown that
as largely privately financed launchers can be developed for markedly reduced
costs than for government developed ones. It was able to develop the nine
engine, not just two or three, Falcon 9 for ca. $300 million, and this
included the costs of developing a whole new engine and a whole new stage. It
is larger in all of number of engines, payload capacity, gross mass, dry mass,
number of stages, etc. than the multi-Vulcain Ariane core stage would be. Plus
there is also the key fact the engine and stage already exist for the
multi-Vulcain so you don't have that development cost.
Quite frankly if EADS Astrium couldn't figure out how to add on one to two
engines onto the Ariane 5 core *privately financed* for less than the $300
million SpaceX spent to develop the *entire* Falcon 9, then they are doing
something wrong and should ask SpaceX to do it for them. But there is no doubt
in my mind that the European engineers are at least as smart as the SpaceX
engineers if not smarter and can do it in a low cost fashion if they have to.
Yes, if they have to. EADS Astrium and the ESA are in a partnership. The ESA
needs EADS Astrium for their launchers and spacecraft, but EADS Astrium needs
the ESA for its aerospace division. Then one way the ESA could encourage EADS
Astrium to privately finance the conversion of the Ariane core to
multi-engines is to agree to pay for the development of the larger, higher
performance engine for that later time frame.
Considering the size of the Ariane core stage compared to the entire Falcon 9
rocket, I suspect this conversion could be done, privately paid for, for under
$100 million, really no problem at all for EADS Astrium to finance it
themselves. But there is a very important way EADS Astrium could attract
financing from outside investors. Reports recently are that Europe has given
up on plans of an indigenous manned spaceflight capability because of cost.
But SpaceX has shown and NASA has confirmed with its commercial crew program
that manned launchers and spacecraft can be developed for costs in the few
hundred million dollars range as privately financed, perhaps with governmental
seed money.
Then a quite important advantage of the multi-Vulcain Ariane approach is that
both the single stage and two stage versions can be used for manned launchers.
So this would provide Europe with a manned spaceflight capability at a short
time frame and at low cost. This is clearly something that could attract
outside investors.
To summarize, the ESA should make a public accounting of the comparison of
the multi-Vulcain approach compared to the new large, expensive engine
approach for a new launcher. Evidence from other space agencies suggests the
multi-engine approach can be cost effective. The ESA should encourage EADS
Astrium to privately finance the conversion. Lastly, and most importantly, the
multi-engine approach can provide Europe with a manned spaceflight capability
in a short time frame.
Robert Clark
c.f.,
A low cost, all European, manned launcher.
« on: March 09, 2012, 07:14:49 pm »
http://www.secretprojects.co.uk/forum/index.php/topic,14692.msg146544.html#msg146544
Re: A low cost, all European, manned launcher.
« Reply #21 on: March 22, 2012, 04:27:58 pm »
http://www.secretprojects.co.uk/forum/index.php/topic,14692.msg147801.html#msg147801
=====================================================================================
