The Reaction Engines Skylon/SABRE Master Thread (6)

[john smith 19]

IIRC the original "HOTOL" patent (which was classified by the UKG) used LH2 directly between the pre cooler and the compressor drive turbine.

SABRE de-couples these with the Helium loop.

With the various drive turbines now being driven by inert Helium rather than GH2 the seals between the hot GH2 drive turbines (of the RR545?) and the air or LO2 are no longer "Criticality 1" failures, in the way the similar seals on the SSME (HPOTP) were. 

[john smith 19]

Reaction Engines now under contract with DARPA!

https://www.reactionengines.co.uk/reaction-engines-awarded-darpa-contract-to-perform-high-temperature-testing-of-the-sabre-precooler/

Yet more development work I suspect not unrelated to the so called SR-72 amongst other things.

I thought it was phase II of AF161-074: Durable Pre-cooling Heat Exchangers for High Mach Flight, so more testing than development, I think

Fabricate a scaled prototype of the heat exchanger utilizing the proposed manufacturing approach. Conduct testing in a relevant laboratory environment. Develop and validate performance and lifting models based on the testing. Utilize this information to increase the understanding of how the heat exchanger integrates into a platform or platforms

Note also they are not just constructing this HX test article, they are also building a new hypersonic test facility to test it in.

Which I think may be the first new hypersonic test facility in the US for some time, and should allow either refinement of other parts of the system or generate revenue for REL

The Q&A, where he talks about the importance of avoiding ITAR contamination is very interesting. I think historically REL have thought this was just tough to crack but they seem to have a clear idea of how to manage this situation.

[john smith 19]

Reusable SSTO, VTVL or otherwise, doesn't require any fundamental breakthroughs. The question is economic, since you need a larger vehicle for the same payload.

The mass ratio would have to be good, but mass ratios that would be SSTO class with modern engines have been demonstrated since the early 60s (Titan II first stage for example... the mass ratio on the old Atlas was completely ridiculously low, but it was probably too flimsy for reentry...)

You're both completely right and completely wrong.

A rocket powered SSTO has been possible since the early 60's but you lose 1/3 to 2/3 of the capacity of an equivalent VTO TSTO. In a market for funding the VC's just ask "So why should I give you X dollars/pounds/yen/euros to build a vehicle that's only got that a capacity 1-2/3 that of TSTO, or is 2-3x bigger"

The answer is of course that no one wil. The benefits of rocket SSTO have simply never outweighed the loss of performance.

SABRESkylon matches TSTO payload fraction in a SSTO vehicle.

It's big because rockets that put 15 tonnes into LEO are also big. But it's not bigger than an equal sized capacity TSTO.

[Star One]

Reaction Engines now under contract with DARPA!

https://www.reactionengines.co.uk/reaction-engines-awarded-darpa-contract-to-perform-high-temperature-testing-of-the-sabre-precooler/

Yet more development work I suspect not unrelated to the so called SR-72 amongst other things.

I thought it was phase II of AF161-074: Durable Pre-cooling Heat Exchangers for High Mach Flight, so more testing than development, I think

Fabricate a scaled prototype of the heat exchanger utilizing the proposed manufacturing approach. Conduct testing in a relevant laboratory environment. Develop and validate performance and lifting models based on the testing. Utilize this information to increase the understanding of how the heat exchanger integrates into a platform or platforms

Note also they are not just constructing this HX test article, they are also building a new hypersonic test facility to test it in.

Which I think may be the first new hypersonic test facility in the US for some time, and should allow either refinement of other parts of the system or generate revenue for REL

The Q&A, where he talks about the importance of avoiding ITAR contamination is very interesting. I think historically REL have thought this was just tough to crack but they seem to have a clear idea of how to manage this situation.

Obviously this is hard to say for certain but I imagine LM & AJ would have probably both  constructed new hypersonic test facilities in support of the SR-72 test program. In fact I am sure there was a press release about a new hypersonic wind tunnel though no particular program was attached to it.

[JCRM]

Note also they are not just constructing this HX test article, they are also building a new hypersonic test facility to test it in.

No they're not, they're

constructing a new high-temperature airflow test facility, located in Colorado. Under the DARPA program, the company aims to establish the facility’s capability to provide airflows in excess of 1800°F (1000°C), analogous to air-breathing flight above Mach 5

they're simulating the conditions after the intake, so (high) subsonic flow at high temperature, as opposed to hypersonic at ambient temperature

[Avron]

Anyone tested a sub-scale rocket engine running on H2 and compressed air yet?

[john smith 19]

Anyone tested a sub-scale rocket engine running on H2 and compressed air yet?

Yes. Multiple times. DLR (under REL contract) also tested air and LOX cooling of the combustion chambers.

[CrewtaiL]

Anybody know what exactly the DARPA grant is funding? Is it the construction of the High Temp. tunnel? Also, why construct it in Colorado and not the UK? Trying to understand the legal implications of the location.

[Star One]

Anybody know what exactly the DARPA grant is funding? Is it the construction of the High Temp. tunnel? Also, why construct it in Colorado and not the UK? Trying to understand the legal implications of the location.

Because the grant is to their US company not REL UK.

[JCRM]

Anyone tested a sub-scale rocket engine running on H2 and compressed air yet?

Yes. Multiple times.

Including STERN, STRICT, and STOIC.

Anybody know what exactly the DARPA grant is funding? Is it the construction of the High Temp. tunnel? Also, why construct it in Colorado and not the UK? Trying to understand the legal implications of the location.

Because the grant is to their US company not REL UK.

In part because the testing work is being done under ITAR, so while success/failure will be known, the exact details have to be filtered by Adam Dissel, at least according to the recording above. Not ideal from REL's point of view, but I guess if it works it doesn't really matter, and if it doesn't they have to look at getting UK funding to investigate further if they can't get a good enough idea of what went wrong.

[Spartacus]

So, decades of work by dedicated UK scientists and engineers, along with £60 million of UK taxpayers money, has ended up in a secret US military programme.

Q:  Who is responsible for this, and why?

A:  Follow the money....

[JCRM]

So, decades of work by dedicated UK scientists and engineers,

who have always said they'll sell their products to whoever wants them. That being the nature of a private business

along with £60 million of UK taxpayers money

that moeny was e development of a core engine demonstrator. the precooler, being tested by the Americans, is not part of the core engine, and so this is entirely separate.

has ended up in a secret US military programme.

The Americans are paying for a Reaction Engines Ltd precooler to be tested by Reaction Engines Inc. They have deemed that the results of the experiment fall under the ITAR purview.
At least two AFRL designs for TSTO vehicles have been made public.

Q:  Who is responsible for this, and why?

I suspect a good number of people from REL, and the AFRL have been working quite hard to make this happen, probably with considerable help from the American and UK governments. I congratulate them on pulling it off.

A:  Follow the money....

REL have been for a quarter century, Alan Bond for over 35 years.

[Spartacus]

The only reason for the development of the SABRE engine, and the RB545 before it, was to power a SSTO spaceplane. If you want a TSTO with a reusable first stage then Elon Musk will sell you one tomorrow, without a 5-10 year, multi-billion dollar development programme.

The £60 million grant, of UK taxpayers money, was precisely to PREVENT the USA getting their hands on it, and to preserve the technology to be developed in the UK:   https://www.gov.uk/government/speeches/uk-space-conference-2013

But the founders and directors of REL were forced out, and the money men thought that they would make a fortune out of it.

[john smith 19]

In part because the testing work is being done under ITAR, so while success/failure will be known, the exact details have to be filtered by Adam Dissel, at least according to the recording above. Not ideal from REL's point of view, but I guess if it works it doesn't really matter, and if it doesn't they have to look at getting UK funding to investigate further if they can't get a good enough idea of what went wrong.

Indeed. Avoiding "ITAR contamination" sounds a pretty tricky thing but it's got to be done to make a product that can be sold outside of the US.

I'd thought it was impossible once you accepted money from any part of the USG but that seems to be too pessimistic a view. It's a tribute to REL's pragmatism that they are still in business when probably their nearest contemporary in terms of history (XCOR) shut down recently.  2020 looks to be a very exciting year.

On another thread someone pointed out that a US company buying a French made IMU could not then re-export the complete system back to France, despite being able to export the system without the IMU to France without a problem.

The only reason for the development of the SABRE engine, and the RB545 before it, was to power a SSTO spaceplane. If you want a TSTO with a reusable first stage then Elon Musk will sell you one tomorrow, without a 5-10 year, multi-billion dollar development programme.

Actually he won't. 
He will sell you a ticket to ride on a vehicle with (if it follows typical TSTO ELV failure statistics) a 1 in 50 chance of going bang.

BTW Welcome to the forum.

That said if SABRE can deliver on it's planned Isp and T/W targets (and it's got some slack in the T/W figures apparently) then the question is can you design a single aircraft to fly the whole mission. The modelling done by SAIC suggests you need a TSTO but their mass estimates seem pretty crude. Their mass for landing gear is nearly double that of the XB70, which was actually built.

The £60 million grant, of UK taxpayers money, was precisely to PREVENT the USA getting their hands on it, and to preserve the technology to be developed in the UK:   https://www.gov.uk/government/speeches/uk-space-conference-2013

The goal was for the HMG funds to be a "sign of good faith" by HMG in the company to act as pump priming money.

However it seems when the money (3 years later) was released the conditions had changed (according to REL tesimony to a Commons Select Committee) requiring them to have a partner before the money was released. Hence the BAe investment (20% for £20m), which seems a generous slice of the company for not very much (by aerospace standards).

The BAe CEO is (AFAIK) the only defense contractor with unlimited access to a head of state (the UK Prime Minister). AFAIK no CEO of a US company has such a privileged arrangement.

But the founders and directors of REL were forced out, and the money men thought that they would make a fortune out of it.

Johns Scott is dead, AFAIK both Varvill and Bond remain active within the company.

[Archibald]

A neat thing about Musk 2017 IAC is that BFR will not crush Skylon. The two systems really complement each other.
Skylon will be far moss flexible than BFR, it will handle classic (small) satellite launches in place of Ariane-like ELVs. BFR will assume suborbital passenger transportation (killing the sonic boom by flying in space), heavy lift, and Moon / Mars colonization.

[Mutley]

Johns Scott is dead, AFAIK both Varvill and Bond remain active within the company.

Actually Alan Bond has retired today
https://www.reactionengines.co.uk/alan-bond-retires-reaction-engines/

[john smith 19]

Actually Alan Bond has retired today
https://www.reactionengines.co.uk/alan-bond-retires-reaction-engines/

Noted.

Note that REL is still a running business.

I wonder how many "New Space" companies that were founded around the same time are as well?

[CrewtaiL]

The £60 million grant, of UK taxpayers money, was precisely to PREVENT the USA getting their hands on it, and to preserve the technology to be developed in the UK:   https://www.gov.uk/government/speeches/uk-space-conference-2013

But the founders and directors of REL were forced out, and the money men thought that they would make a fortune out of it.

Is any of this true? The money was given to REL to act as fillip in their development. It appears to have worked. Secondly, the technological know-how is staying in the UK; a HX is being made to the specifications of a customer and will be delivered them in 2018. Selling your wares to customers around the world is kind of what engineering firms do, at least the successful ones.

Also, what evidence any of them were forced out? One died, another retired today, a third remains and is influential in the company.

[Star One]

Johns Scott is dead, AFAIK both Varvill and Bond remain active within the company.

Actually Alan Bond has retired today
https://www.reactionengines.co.uk/alan-bond-retires-reaction-engines/

It wouldn't surprise now me if we don't hear of a full buy out of REL either by BAe or Rolls Royce in the next 12 months.

[JCRM]

The only reason for the development of the SABRE engine, and the RB545 before it, was to power a SSTO spaceplane.

Indeed, and SSTO is the best application of a SABRE 4 engine.

If you want a TSTO with a reusable first stage then Elon Musk will sell you one tomorrow, without a 5-10 year, multi-billion dollar development programme.

A nice refinement of existing technologies, but the initial proposition put to investors was an expendable launch vehicle, with a vague roadmap to reusability. Having a lower risk (but inefficient) TSTO offering potentially makes SABRE development more inviting to investors: after the 1/2 billion for the engine, a system to use it will only be a couple of billion more and a couple of years more before an investor starts to see an income, rather than 17 billion, and ten-fifteen years (or eight years, if a funded milestone driven development program is in place)

The £60 million grant, of UK taxpayers money, was precisely to PREVENT the USA getting their hands on it, and to preserve the technology to be developed in the UK:

The work being undertaken is to test the precoolers, not give them away. Who knows, Reaction engines Inc may even buy the precoolers from REL to test them. The precoolers are pretty well understood, there's a patent for the overall layout going back to HOTOL timeframe.

The technology is still being developed with a UK lead. SABRE/Skylon development has had elements being developed overseas for years before then:
SOMA being an Airbus engine concept
Developing Pyrosic to acheive System2 performance Pyromeral, France, before 2008
Intakes and Ramjets by Bayern-Chemie, Germany
Oxidiser cooled compustion chamber, Astrium Germany 2009
Turbine design, Von Karman institute, Belgium, 2007

It would be a great shame to see the technology be given awy, but that isn't what is happening here. And even then it would be preferable for it being given away than it be abandoned.