The Reaction Engines Skylon/SABRE Master Thread (7)

[JCRM]

With the recent announcements about Cornwall Newquay airport becoming the new UK "horizontal spaceport", ostensibly to lure LauncherOne, might we see some facilities work at Newquay to support actual spaceplanes?

But, fitting in a 5 mile long runway would be a bit troublesome, looking at the map (with the main runway being about 10K ft?)

The AFRL  TSTO concept used a higher T/W ratio allowing it to take off from a 3km runway. Cornwall was explicitly used in the case study.

Not having to build a whole new runway (and find the land for it) to test the engine would allow operational experience of the engine class, and build confidence without needing a major infrastructure spend in the order of 1-3 billion.

[JCRM]

BBC's Radio4 "Today" program was at Farnborough, talking to Boeing and REL, broadcast this morning. Unfortunately you need an account for that, but the Best of Today podcast contains (at least) part of the interviews, Mark Thomas is on at 5:10 for slightly less than three minutes.
* Discusses the "super cooler"
* SABRE is a new class of engine supporting hypersonic flight and low cost access to space.
* Colorado is the final validation for the precoolers later this year.
* Core engine test 2020
* Flying demonstrator hopefully middle of the next decade.
* [future spaceplane] probably TSTO in the first case


The REL stand at Farnborough has a "new" Skylon 3D model as it's backdrop - which led me to the REL website which has had a revamp.

Unfortunately the diagram on the site isn't as at quite as nice an angle.


The revamp has added lots of style, and more than a little bit of substance:

https://www.reactionengines.co.uk/sabre/core-engine-demonstrator
https://www.reactionengines.co.uk/sabre/htx
https://www.youtube.com/watch?v=bIO_B40g03U

[t43562]

Well, Farnborough was a bust for me where REL was concerned. Hall 4 was closed (at least when I looked) and there was nobody at their little stand in the space section.

[JCRM]

Well, Farnborough was a bust for me where REL was concerned. Hall 4 was closed (at least when I looked) and there was nobody at their little stand in the space section.

That's a shame, but thanks for trying.

Guy Norris from Aviation week did manage to get a word with Mark Thomas and again "super cooler" was used in relation to the precooler.

[knowles2]

The UK has just announce it building a new fighter the tempest.

I think Reaction Engine can squeeze a bit of money out of this program. It could provide a continuous revenue stream by getting rolls royce to adopt it pre coolers for the fighter engine.

 Reaction Engine do claim they offer a lot of advantages,  https://www.reactionengines.co.uk/sabre/pre-cooled-turbojet.

This is Roll Royce video on the new engine https://www.youtube.com/watch?v=X8kTZ9I8f_U
Could the guy fit any more buzz words in this video! Improve thermal management is one of Reaction Engine claims through.
 
Also nearly all the partners involve in Tempest are now also actively involved in Reaction Engine.

I'm taking a little guess here but to be a truly next gen aircraft the Tempest will be base on a all electrical system. incorporate electrical landing gears and replace most of hydraulic systems with electrical systems, which should produce plenty of transferable knowledge to incorporate those technologies into skylon. 

Also could reaction engines take advantage of Project Magma https://www.baesystems.com/en/article/first-magma-flight-trials to further lighten skylon?

Project Tempest if the UK truly wants a true 6th gen aircraft, should mature all of these technologies making them cheaper to integrate them into Skylon and produce a even lighter vehicle and may be even a simpler spacecraft to build as well.

[Archibald]

you really don't need to post the same thing in two different threads   

[knowles2]

you really don't need to post the same thing in two different threads   

Got the threads mix up.  This more suitable thread I thought. 

[JCRM]

It looks like they're having a bit of a redo of the TF1 embankment over the escape tunnels, both the near and far one look a little worse for wear, and the one on the left wall too if it's shadow is anything to go by.

looked fine a month ago, based on the image in Googles cache

[JCRM]

An updated time-lapse of the construction work at TF-1. One of the new escape tunnels makes a brief appearance at 1:36
https://www.youtube.com/watch?v=srZzRVNj6uI

[john smith 19]

An updated time-lapse of the construction work at TF-1. One of the new escape tunnels makes a brief appearance at 1:36

AIUI this is the first brand new rocket engine test facility in the UK in decades

I think we can only hope the design work on the first engine it's going to test is moving as smoothly.

[adrianwyard]

Please note: the following is intended purely for amusement, and actually makes no point whatsoever:

I wouldn’t dare post this in the SpaceX BFR thread, but I can’t be the only one who’s amused that SpaceX's design has evolved into one with large aero-surfaces that requires powerful and presumably heavy actuators (HOTOL-scale hydraulics?) and re-enters belly first enjoying a low ballistic coefficient!

But seriously, this is not meant to restart a Skylon vs BFR debate. I really doubt there's anything new to say.

Carry on :-)

[john smith 19]

Please note: the following is intended purely for amusement, and actually makes no point whatsoever:

I wouldn’t dare post this in the SpaceX BFR thread, but I can’t be the only one who’s amused that SpaceX's design has evolved into one with large aero-surfaces that requires powerful and presumably heavy actuators (HOTOL-scale hydraulics?) and re-enters belly first enjoying a low ballistic coefficient!

But seriously, this is not meant to restart a Skylon vs BFR debate. I really doubt there's anything new to say.

Carry on :-)

The very large actuators needed to drive the control canards on the front of HOTOL were in fact a key driver of the Skylon design.

At first the high forebody lifting forces are kept in check by the mass of LH2 inside it, but as that's burnt off you have to apply larger and larger control surface deflections to keep the nose at the right orientation. Alan Bond talks about this in a video on YT and describes the actuator force size as "About that of a small trawler"

The problem is less extreme with Shuttle because all its main propellant was in the ET, but it was still unflyable without the flight computers adding lots of small tweaks to every pilots joystick command.

I suspect the problem will be shared by any launch vehicle that takes off vertically and uses aerodynamic lift for any significant part of its flight. It's the combination of very low structural mass fraction and very high point masses in the tail IE the engines.

The answers are
a) Move the engines (as Skylon does) to midbody. AFAIK no one's ever tried this with a vertical TO vehicle. The flame plume pretty much mandates some sort of streamlined strut to avoid the plume boiling off any cryogenic propellant (oh hell, let's call them wings.    )
b) Add stages. This raises the required structural mass fraction per stage, so the stages empty weight goes up to more effectively counter the mass of the engines.

Of course then you're looking at a 3 stage or more VTOL vehicle to develop and I'm not sure how effective this strategy really is.

[EDIT A data point. When they looked at electric TVC for the Shuttle SSME's the power estimate per axis, per engine was about 42.5Kw, or 57 Hp. I've never seen an estimate for the actuator power of the Shuttles wing trailing edge actuators, but likely to be substantial. OTOH a longer wing implies a longer leverage arm, so small deflections from the outer surfaces could be as effective as bigger ones nearer into the body. ]

[Chris Bergin]

No Skylon vs BFR. It sets people's hair on fire!

[Star One]

Reaction Engines at New Scientist Live 2018

https://www.youtube.com/watch?v=ZTFshPECoeE

[adrianwyard]

No Skylon vs BFR. It sets people's hair on fire!

Can I ask if any of the Skylon work on actively cooled canards or thermal protection materials might be applicable to the SpaceX design without hair catching alight?

[john smith 19]

No Skylon vs BFR. It sets people's hair on fire!

Can I ask if any of the Skylon work on actively cooled canards or thermal protection materials might be applicable to the SpaceX design without hair catching alight?

AIUI REL went with the idea of steam cooling because there is actual flight history of this concept. Specifically a USAF programme which tested at least one reentry vehicle with it. The report was on the DTIC website.

While using heatpipes to move the intense (but localized) leading edge heat to the upper surface was looked at for Shuttle AFAIK it's never been flown. Being a closed system it has no fluids to replace or contamination issues but actual flight tested hardware puts the transpiration cooling concept in pole position.

So if SX wanted to use it they'd just look up the relevant DoD reports.

The preferred structural materials for Skylon are so far outside of the US skills base, and so tailored to the design of a HTOL vehicle that it's very doubtful SX would save anything by using them. They are very heavily invested in CFRP.

[t43562]

There's a segment in here about REL and their TF1 test facility which shows you the (empty) interior at about 1m04s:

https://www.youtube.com/watch?v=RUDdwEYy4vQ&t=1m03s

[john smith 19]

No Skylon vs BFR. It sets people's hair on fire!

Can I ask if any of the Skylon work on actively cooled canards or thermal protection materials might be applicable to the SpaceX design without hair catching alight?

AIUI REL went with the idea of steam cooling because there is actual flight history of this concept. Specifically a USAF programme which tested at least one reentry vehicle with it. The report was on the DTIC website.

While using heatpipes to move the intense (but localized) leading edge heat to the upper surface was looked at for Shuttle AFAIK it's never been flown. Being a closed system it has no fluids to replace or contamination issues but actual flight tested hardware puts the transpiration cooling concept in pole position.

So if SX wanted to use it they'd just look up the relevant DoD reports.

For those interested in the (surprisingly) wide range of techniques for cooling and directional control of reentry vehicles a compilation was done during (AIUI) the kick off to the "Star Wars" programme. It's called "Maneuvering Aerothermal Technology (MAT) Data Bibliography by Martellucci, Weinberg and Page of Science Applications Inc BMO-TR-82-15
Obviously quite a lot of the source reports were classified but nearly 40 years later I'd guess quite a few are now available. Being able to chew through the raw data with computers 4 decades more advanced and software with 4 decades more theory behind it should produce some interesting results.

[FutureSpaceTourist]

https://twitter.com/ReactionEngines/status/1059424468039335936

http://www.imeche.org/news/news-article/the-great-british-space-age-tackling-the-satellite-backlog

One concept, the Skylon spaceplane, has been “a little bit of a distraction” in the public eye from the company’s engine development, says a spokesman. The firm is considering “a number” of concepts, and will speak to vehicle developers after testing of Sabre.

[t43562]

I realise that this is on the edge of the topic and that I am on thin ice but I beg indulgence because I think there's nowhere with people more interested:

http://epic-src.eu/wp-content/uploads/1.-Keynote-Speech-Alan-Bond.pdf