A low cost, all European, manned launcher.

[RGClark]

This is in reference to an argument in post #156 that the Ariane 5 core stage can be SSTO with 3 Vulcain engines.

The most important accomplishment of SpaceX may turn out to be they showed in such stark terms the savings possible when launchers are privately financed:

SpaceX Might Be Able To Teach NASA A Lesson.
May 23, 2011 By Frank Morring, Jr. Washington

“I think one would want to understand in some detail . . . why would it be between four and 10 times more expensive for NASA to do this, especially at a time when one of the issues facing NASA is how to develop the heavy-lift launch vehicle within the budget profile that the committee has given it,” Chyba says. He cites an analysis contained in NASA’s report to Congress on the market for commercial crew and cargo services to LEO that found it would cost NASA between $1.7 billion and $4 billion to do the same Falcon-9 development that cost SpaceX $390 million. In its analysis, which contained no estimates for the future cost of commercial transportation services to the International Space Station (ISS) beyond those already under contract, NASA says it had “verified” those SpaceX cost figures. For comparison, agency experts used the NASA-Air Force Cost Model—“a parametric cost-estimating tool with a historical database of over 130 NASA and Air Force spaceflight hardware projects”—to generate estimates of what it would cost the civil space agency to match the SpaceX accomplishment. Using the “traditional NASA approach,” the agency analysts found the cost would be $4 billion. That would drop to $1.7 billion with different assumptions representative of “a more commercial development approach,” NASA says.

http://www.aviationweek.com/aw/generic/story_generic.jsp?channel=awst&id=news/awst/2011/05/23/AW_05_23_2011_p36-324881.xml

The SpaceX experience of developing a launcher in the Falcon 9 at 1/10th the cost of a government financed one also holds for the crew capsule development costs since the Dragon capsule cost about $300 million to develop while the Orion costs several billion and still counting. So it can't be said this cost saving is just due to the Falcon 9 being, so far, unmanned.

Speaking about Orion and billions of dollars, I read an article about plans to use the Orion on the Ariane 5 to get a European manned spaceflight capability:

French govt study backs Orion Ariane 5 launch.
By Rob Coppinger on January 8, 2010 4:45 PM
http://www.flightglobal.com/blogs/hyperbola/2010/01/french.html

This would cost several billion dollars to man-rate the Ariane 5. I have to believe the solid rocket boosters, which can not be shut down when started, play a significant portion in that high cost. The article mentions also the core stage would have to be strengthened. But such strengthening is based on it having to support a 20 mT Orion capsule and a 20 mT upper stage which wouldn't be used with a much smaller capsule such as the Dragon, at a dry mass of about 4 mT.

Note also that quite likely an even smaller manned capsule could be designed at about a 2 mT dry mass to carry a 3 man crew, which given its half size compared to the Dragon, might cost in the range of only $150 million to develop as privately financed. It's hard to imagine that private investment could not be found to finance such a capsule development when it could lead to a manned European space capability.

In regards to the costs of a privately financed SSTO version of the Ariane launcher we might make a comparison to the Falcon 9. It cost about $300 million to develop and this includes both the structure and engines, the engines making up the largest share of the development cost of a launcher. But for the SSTO Ariane both engine and structure are already developed and it's only a single stage instead of the two stages of the Falcon 9. You would have the development cost of adding 2 additional engines and of the new avionics, but again I have to be believe the development cost would once again be less than the SpaceX development cost of the Falcon 9 if privately financed.

I also read that the ESA is attempting to decide whether to upgrade the Ariane 5 or move to a Next Generation Launcher(NGL):

Ariane rocket aims to pick up the pace.
25 June 2011 Last updated at 06:39 ET
http://www.bbc.co.uk/news/science-environment-13911901

Thu 9 February, 2012
France, Germany To Establish Working Group To Resolve Ariane 5 Differences.
By Peter B. de Selding
http://www.spacenews.com/policy/120209-france-germany-resolve-ariane5-differences.html

If the NGL is chosen then a quite expensive new large engine development would have to be made, and the launcher might not enter service until 2025. In contrast the SSTO-Ariane, given that the engine and stage already exist, a prototype probably could be ready within 1 to 2 years, and moreover by using a second stage it could also be used to launch the medium sized payloads.

So the SSTO-Ariane would solve the twin problems at low cost of providing Europe with a manned spaceflight capability and giving it a lower cost medium lift capability.


Bob Clark

 

[Urwumpe]

OK, that is what I just call "test data".

 

[RGClark]

Actually, it doesn't have to be a SSTO. I was arguing for using a much smaller capsule than the Orion for then you wouldn't need the full Ariane 5 launcher, with the two large strap on boosters, so it would be easier and cheaper to man-rate.
If you still give the Ariane 5G core stage two additional Vulcain 2's, then you can lift greater payload using an upper stage than with the SSTO version. You would need to include the mass of the interstage in this case to support the weight of the upper stage and payload, call it 1,000 kg for the interstage.
In the calculation I'll use the 15.6 mT dry mass I used before for the Ariane 5G with the two extra Vulcain 2's and again a 434 s Isp for the Vulcain 2. I'll get the specifications for the LH2/LOX upper stage also from the SpaceLaunchReport page on the Ariane 5, at a 14.9 mT propellant load, 4.5 dry mass, and 446 s Isp of the upper stage cryogenic engine. I also include in the calculation 1 mT for the interstage that will be in the first stage delta-V calculation only since it is jettisoned along with the first stage. Then you could lift ca. 10 mT to orbit:

434*9.81ln(1 + 158/(15.6 + 19.4 + 10 + 1)) + 446*9.81ln(1 + 14.9/(4.5 + 10)) = 9,434 m/s.

This could then loft a Dragon sized capsule. It could also loft the Boeing CST-100 capsule and the Sierra Nevada Dream Chaser since these are both planned to be launched by the Atlas V version without the side boosters, which has a ca. 10 mT LEO payload capability.
So this could compete for those launches of these manned spacecraft planned now only to be carried by either the Falcon 9 or Atlas V. This launcher again should have comparatively low development cost since the engines and stages are already developed and you would have only the development cost of adding on the two engines and the new avionics.
This option should be more palatable to the ESA since it avoids the controversial SSTO's. Of course at some point it would be realized, "Hmm, if we made the capsule half the size of those other ones to carry just three people then that first stage by itself could carry it, and we wouldn't have that extra expense of the upper stage ..."


Bob Clark

 

[Urwumpe]

of course, you then ignore a small detail. How high is the sea-level thrust and sea-level specific impulse of a Vulcain-2 (optimized for high altitude operations)?

 

[Hlynkacg]

of course, you then ignore a small detail. How high is the sea-level thrust and sea-level specific impulse of a Vulcain-2 (optimized for high altitude operations)?

That and how much in the way of structural modifications would be needed to install them.

 

[RAF92_Moser]

of course, you then ignore a small detail. How high is the sea-level thrust and sea-level specific impulse of a Vulcain-2 (optimized for high altitude operations)?

Thrust: About 939.5 kN
ISP: 318 s

http://www.astronautix.com/engines/vulcain2.htm

Can someone verify these numbers?

 

[Urwumpe]

That and how much in the way of structural modifications would be needed to install them.

Yes. I currently experiment with a small program for learning NetBeans RCP... A rocket design tool for being able to keep track of RGClarkes first order estimates. :lol: Thank god I now have THE book about programming in this RCP, the tutorials are good but leave many questions unanswered.

The next non-fiction book budget is already reserved for finally learning technical mechanics... then I will maybe know how to do better structural mass predictions. :lol:

---------- Post added at 06:55 PM ---------- Previous post was at 06:51 PM ----------

Thrust: About 939.5 kN
ISP: 318 s

http://www.astronautix.com/engines/vulcain2.htm

Can someone verify these numbers?

Sounds pretty fitting to me, estimating the sea level performance from that performance data results in similar numbers.

http://cs.astrium.eads.net/sp/launcher-propulsion/rocket-engines/vulcain-2-rocket-engine.html

 

[RGClark]

of course, you then ignore a small detail. How high is the sea-level thrust and sea-level specific impulse of a Vulcain-2 (optimized for high altitude operations)?

The vacuum Isp only was used to calculate delta-V because of a common technique in the industry to regard the reduced Isp at sea level as a loss and add this onto the required delta-V to orbit just like you would add on the gravity loss and the air drag loss. See here:

============================================
Newsgroups: sci.space.tech
From: [email protected] (Mitchell Burnside Clapp)
Date: 1999/11/27
Subject: Re: X-33 vs. DC-X

In real industry discussions of these issues, back pressure losses, which
relate the Isp at sea level to vacuum Isp is ALWAYS billed as a velocity loss due to back pressure, rather than an Isp loss. In such a discussion, the term "trajectory averaged Isp" has no meaning, because the variations in Isp are accounted as back pressure losses. The 287 sec number I reported is for the LR-87 engine used in the Titan II ICBM, and is the vacuum number. Any correction is made on the Delta-V side, not the Isp side.

Mitchell Burnside Clapp
CEO
Pioneer Rocketplane
[email protected]
"The glass is neither half full nor half empty. It is twice as large as it
needs to be."

===========================================
===========================================
Newsgroups: sci.space.tech
From: Josh Hopkins <[email protected]>
Date: 1999/12/04
Subject: Re: X-33 vs. DC-X
Jens Lerch wrote:
>...
> Still I have sometimes seen the Isp of the Atlas' booster and sustainer
> listed only as ~260 sec and ~220 sec respectively, which is obviously
> the sea level Isp.

I concur with Mitch on this one. You do frequently see first stage
propulsion system Isp listed at sea level (though usually in addition to
a vacuum number). However, this is typically used only as a metric for
understanding the engine, not as a general input to a vehicle
performance model. You almost always input the vacuum Isp or Thrust and
the engine exit area, and let the computer work out the effective thrust
at any instant in time. This is probably done in part because the
effective weighted average between vacuum and sea level Isp would depend on the trajectory (how fast you climb). It's not worth the effort to
compute it yourself for every trajectory if the computer can do it for
you. The atmospheric thrust losses then fall out as an ideal velocity
loss.

> >The 287 sec number I reported is for the
> >LR-87 engine used in the Titan II ICBM, and is the vacuum number. Any
> >correction is made on the Delta-V side, not the Isp side.
> Then Mark Wade's site has another wrong figure for the Titan II :-(
> But te Isp of the LR-87 used on the Titan IV has an Isp of just above
> 300 sec, probably because it is somewhat optimized for inflight
> ignition. It also has a bit more thrust and is heavier, so it is of no
> use for a Titan II class SSTO.

Hmm. The Titan II Payload User's Guide doesn't list the Isp. The 2nd
edition of International Reference Guide To Space Launch systems lists
the vacuum Isp of Stage 1 as 296 seconds.
==============================================


Bob Clark

 

[Urwumpe]

Sorry, but in that case of another stupid attempt at argument by authority, I have to note two important details.

1. The lower thrust of the engines at lift-off mean slower acceleration to the point, that the rocket is actually requiring more DV to orbit.
2. The Burnside Clap that you always like to quote, had been a professional for programs that failed to reach their performance goals in the reality. His methodology is flawed and only delivers usable (not good, but tolerable bad) performance estimates for rockets with high initial acceleration - ICBMs for example. In the SSTO case, you should better invert the process around the formula for the back pressure losses and calculate how much back pressure losses you can actually tolerate before a design is unrealistic, instead of ignoring them and say "It is possible." When back pressure losses are 40% of your total DV, some warning lights should appear.

If you need just 20 seconds to pass the 20 km mark, back pressure is no real concern, you are near the vacuum too soon for it giving you significant losses that you need to care for in the first order estimate.


If your rocket will not even lift off, because the engines produce too little thrust at sea level, you should worry.

 

[RGClark]

Sorry, but in that case of another stupid attempt at argument by authority, I have to note two important details.

The lower thrust of the engines at lift-off mean slower acceleration to the point, that the rocket is actually requiring more DV to orbit.

1. The Burnside Clap that you always like to quote, had been a professional for programs that failed to reach their performance goals in the reality. His methodology is flawed and only delivers usable (not good, but tolerable bad) performance estimates for rockets with high initial acceleration - ICBMs for example. In the SSTO case, you should better invert the process around the formula for the back pressure losses and calculate how much back pressure losses you can actually tolerate before a design is unrealistic, instead of ignoring them and say "It is possible." When back pressure losses are 40% of your total DV, some warning lights should appear.

If you need just 20 seconds to pass the 20 km mark, back pressure is no real concern, you are near the vacuum too soon for it giving you significant losses that you need to care for in the first order estimate.

If your rocket will not even lift off, because the engines produce too little thrust at sea level, you should worry.

I trust you will not be offended if I prefer to take the opinion of those with decades of experience in the industry rather than others.

The question about the take off thrust was already answered by someone else in the thread so I didn't address that question.


Bob Clark

 

[Urwumpe]

I trust you will not be offended if I prefer to take the opinion of those with decades of experience in the industry rather than others.

Sure, your freedom to choose and my freedom to object. Especially about such experts. There ain't no such fool like an old fool.

How many SSTOs did you build or did your experts build in the past decades?

The bitter reality for you: As long as you are avoiding the hard work and only do the easy things, it won't be you, who designs a SSTO. And if it is not you - who else should?

There is a fine system engineering handbook from NASA, why don't you learn from it, instead of clinging to five postings by two people from 15 years ago? All your postings are just vanity. You solve no problems, raise no new questions, you only steer SSTO engineering into dead-ends. if that is your goal, to give SSTOs a bad name, you are very successful.

The question about the take off thrust was already answered by someone else in the thread so I didn't address that question.

Ah, the professor of mathematics behavior: He wakes up at night, sees his room in flames, sees the fire extinguisher, mumbles "There is a solution" and goes sleeping again.

I have not seen you include that number in your evaluation. Will it even lift off, Mr?

 

[Notebook]

European manned launcher? Been done...

http://www.flightglobal.com/FlightPDFArchive/1966/1966 - 0663.pdf

http://www.unrealaircraft.com/wings/bac_mustard.php

Well, nearly.

N.

 

[RGClark]

European manned launcher? Been done...

http://www.flightglobal.com/FlightPDFArchive/1966/1966 - 0663.pdf

http://www.unrealaircraft.com/wings/bac_mustard.php

Well, nearly.

N.

Thanks for that. It's interesting that it makes use of a "trimese" arrangement where you use three copies of the same vehicle to get a fully reusable multi-stage craft. This should have lower development cost than producing different crafts for each stage, especially of one large first stage. Quite likely also with modern lightweight composites it could be done with a "bimese" arrangement that uses two copies of the same stage.

The key point I'm making is that if you make your launchers and crewed spacecraft privately financed then they can each be developed at costs in the few hundred million dollars range. Proponents of commercial spaceflight have long argued you can have routine private spaceflight because such manned launchers, though they would have billion dollar development costs, would in fact cost less than the multi-billion dollars the aerospace companies spend in privately developing their new large jet aircraft.

But of course the problem was there is a much larger market for jet aircraft travel. However, if the development costs for such privately financed manned launchers is only a few hundred million dollars then the aerospace companies can make a profit just on the launches for the various national space programs alone. I'm also of the opinion that this will also open up launches carrying private individuals which will improve profitability.

I argued in the thread Boeing's CST-100 that Boeing was likely spending only a few hundred million dollars on their CST-100 crew capsule. By the same token Sierra Nevada does not have several billion dollars at their disposal to privately develop their Dream Chaser spacecraft. So it quite likely also is only costing in the few hundred million dollar range to privately develop.

So in point of fact each of the individual nations of the ESA could have their own manned launch programs when privately developed and financed by their own indigenous aerospace companies, such as for example by [ame="http://en.wikipedia.org/wiki/BAE_Systems"]BAe[/ame] in the UK.


Bob Clarkhttp://www.orbiter-forum.com/showthread.php?p=344320&postcount=47

 

[Notebook]

Thanks for that. It's interesting that it makes use of a "trimese" arrangement where you use three copies of the same vehicle to get a fully reusable multi-stage craft.

I don't think there was any objective to get a "fully reusable multi-stage craft" in those documents. They were development and forward thinking ideas.
From my point of view od course.

N.

 

[RGClark]

I don't think there was any objective to get a "fully reusable multi-stage craft" in those documents. They were development and forward thinking ideas.
From my point of view od course.

N.

Near the bottom of the "Unreal Aircraft" page it suggests this could cut costs by 20 to 30 times over expendable rockets which suggests they were considering the reusability as a means to cut the costs to space.

This is well within current capabilities to achieve for a "bimese" version. For instance you could use the Dream Chaser type structure except the entire airframe aft of the cockpit would be filled with propellant.


Bob Clark

 

[Urwumpe]

The problem is the conjunctive, it could reduce costs that much, but of course, nobody really estimated and calculated operations that soon in development, it is just a coarse figure, that could also have meant "20 times more expensive".

The idea is very good and creative, I did some paper calculations on how such a vehicle could be performing, it is essentially a reusable TSTO. Boosters or drop tanks could also increase performance in that design, but today, you would realize such a vehicle as unmanned, it makes little sense risking two crews for the booster, who could also be replaced by computers. The training advantage is pretty minimal unless you use identical stages, which would not be very effective.

 

[Notebook]

Considering the state of UK space engineering at the time, Blue Streak about to come and go, owing most to ATLAS and Rocketdyne.
Black Arrrow, indigenous, but unloved...Probably no chance anything as ambitious as MUSTARD would have suceeded.
Last thing I know about UK built that seperated in flight was:
[ame="http://en.wikipedia.org/wiki/Short_Mayo_Composite"]Short Mayo Composite - Wikipedia, the free encyclopedia[/ame]

http://www.flightglobal.com/FlightPDFArchive/1938/1938 - 0599.pdf

Either way, it didn't happen then, and I doubt if any manned European launcher will happen in my lifetime. Looking forward to proved wrong!

N.

 

[RGClark]

Just saw the Ariane 5 launch. While it was a great launch there was alot of dark exhaust from the solids.
Another benefit of whichever version of this "Ariane 5 Lite" is used, the SSTO or TSTO, it will just use clean burning hydrogen.


Bob Clark

 

[Ghostrider]

In my most humble experience, "low cost" and "European" are mutually exclusive...:lol:

 

[Urwumpe]

Just saw the Ariane 5 launch. While it was a great launch there was alot of dark exhaust from the solids.
Another benefit of whichever version of this "Ariane 5 Lite" is used, the SSTO or TSTO, it will just use clean burning hydrogen.

The smoke of SRBs isn't that bad, while it contributes to fine dust pollution around the launch site, it is in its amount not worse than what many car engines produce. Each SRB burns a few tons of fuel per second in a small space - the ship that transports the rocket parts from Europe to Kourou likely produces more pollution, since it operates by using the waste of oil refineries as cheap, dirty and ineffective fuel.

Also, a hydrogen first stage would make things way more expensive. The two SRBs cost less than the rest of the rocket.

---------- Post added at 04:56 PM ---------- Previous post was at 04:53 PM ----------

In my most humble experience, "low cost" and "European" are mutually exclusive...:lol:

:thumbup: