Author Topic: The Reaction Engines Skylon Master Thread (5)  (Read 421923 times)

Offline alanr74

  • Member
  • Posts: 5
  • uk
  • Liked: 1
  • Likes Given: 1
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1360 on: 03/19/2016 11:59 AM »
not sure if this is useful, but I snipped the slides from the talk.

https://imgur.com/a/F87pA

Offline Citizen Wolf

  • Full Member
  • *
  • Posts: 158
  • Milky Way, Western spiral arm
  • Liked: 27
  • Likes Given: 26
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1361 on: 03/19/2016 12:11 PM »
I wish someone had asked about nozzle development and whether they've decided to go for ED nozzle's or not. And if not, what were the factors underlying the decision.

Also: from listening to the talk I got the impression that Mark Thomas (&REL) was moving away from trying to develop the skylon design (due to commercial/funding realities) and looking more to develop and prove the engine tech first. Maybe along the lines as suggested by AFRL. Anyone else get that impression, or just me reading too much into his voice and intonation on the point.
« Last Edit: 03/19/2016 12:15 PM by Citizen Wolf »
The only thing I can be sure of is that I can't be sure of anything.

Offline alanr74

  • Member
  • Posts: 5
  • uk
  • Liked: 1
  • Likes Given: 1
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1362 on: 03/19/2016 12:26 PM »
I wish someone had asked about nozzle development and whether they've decided to go for ED nozzle's or not. And if not, what were the factors underlying the decision.

Also: from listening to the talk I got the impression that Mark Thomas (&REL) was moving away from trying to develop the skylon design (due to commercial/funding realities) and looking more to develop and prove the engine tech first. Maybe along the lines as suggested by AFRL. Anyone else get that impression, or just me reading too much into his voice and intonation on the point.

I don't think they've ever been interested in the manufacture of the actual spaceplane (are they called space planes?). It's always been about the engine as to build the actual spaceplane and the engine would be something that is just not feasible.

Offline Citizen Wolf

  • Full Member
  • *
  • Posts: 158
  • Milky Way, Western spiral arm
  • Liked: 27
  • Likes Given: 26
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1363 on: 03/19/2016 01:38 PM »
@alanr74
Yes, but they've always actively promoted the Skylon idea, even going through iterations of designs for the craft. They've said that Skylon was the optimal configuration for the Sabre engine. That's above and beyond just designing an engine.

At least that's been my impression of the story thus far. Every presentation they gave always heavily featured Skylon. My impression from this talk was that, although Skylon would be great, Mark Thomas seemed to be more open to other developmental pathways first.
« Last Edit: 03/19/2016 01:39 PM by Citizen Wolf »
The only thing I can be sure of is that I can't be sure of anything.

Online t43562

  • Full Member
  • *
  • Posts: 172
  • UK
  • Liked: 72
  • Likes Given: 37
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1364 on: 03/19/2016 05:56 PM »
...
At least that's been my impression of the story thus far. Every presentation they gave always heavily featured Skylon. My impression from this talk was that, although Skylon would be great, Mark Thomas seemed to be more open to other developmental pathways first.

He did say that they had done a small project recently but not what it was and that raised my ears. They're getting interest for their manufacturing ability too. Then there's the fact that the only people who almost look like customers (AFRL) have other ideas about what they want.  Skylon needs billions and who is going to provide them? I can see his feeling that REL have survived by the skin of their teeth, have a bit more time thanks to BAE and eventually HMG but they have most of the mountain still to climb.  So I am sure they will do whatever anyone else will pay them to do as I think they did with the Lapcat project.   

I would guess that they probably had a lot of money promised to them at one point and that it disappeared for reasons of the financial crisis or changes in fortune or Spacex or whatever (I remember the point at which 2-300 million seemed to be apparently lined up if I understood it right).   One can speculate, but I would guess that they are having a hard time visualising how they are going to avoid developing a whole lot of nearly usable technology and then suddenly  going "phut" before new investment can come along.

I got the impression too that he thinks there are some strange possibilities out there for the technology that they have developed and that you never know what it might lead to - that he isn't sure whether to be excited or stressed out.  Someone who has felt some ups and downs was my impression. Anyhow, with companies like this it was ever so. :-) That's why they are exciting. I hope they do work out some big weapons contract or deals to make components for other people or  one of those other bits of luck that famous technology companies often seem to need to get themselves kickstarted.








Offline Citizen Wolf

  • Full Member
  • *
  • Posts: 158
  • Milky Way, Western spiral arm
  • Liked: 27
  • Likes Given: 26
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1365 on: 03/19/2016 08:37 PM »
t43562
**I remember the point at which 2-300 million seemed to be apparently lined up if I understood it right**

That's what a lot of us seemed to think, but to be honest that might just have been ourselves seeing things where there was nothing. REL never said such a thing.

But as you say, they've hung on until now by the skin of their teeth. The BAE buy-in was a surprise (to me at least) and although REL may welcome the money and profile BAE bring with them, it did seem rather cheap for the percentage stake that BAE got. It seems like they were down to few options with financial and commercial realities beginning to bite.

From the looks of things now, I would guess that Skylon, as originally imagined by Alan Bond and Co, is dead in the water. I'd guess that the Sabre tech is first going to appear in a USAF project.
The only thing I can be sure of is that I can't be sure of anything.

Online Hankelow8

  • Full Member
  • *
  • Posts: 155
  • UK
  • Liked: 112
  • Likes Given: 40
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1366 on: 03/19/2016 09:41 PM »
t43562
**I remember the point at which 2-300 million seemed to be apparently lined up if I understood it right**

That's what a lot of us seemed to think, but to be honest that might just have been ourselves seeing things where there was nothing. REL never said such a thing.

But as you say, they've hung on until now by the skin of their teeth. The BAE buy-in was a surprise (to me at least) and although REL may welcome the money and profile BAE bring with them, it did seem rather cheap for the percentage stake that BAE got. It seems like they were down to few options with financial and commercial realities beginning to bite.






From the looks of things now, I would guess that Skylon, as originally imagined by Alan Bond and Co, is dead in the water. I'd guess that the Sabre tech is first going to appear in a USAF project.

Regrettably I have to agree with you.

I believe Alan Bond might have taken a back seat in the company, and is acting on a semi-retired basis only.
He has put his heart and sole into the project and  Skylon looks more distant then ever now.

I think the company will now focus on development of various aspects of heat-exchanger components.
I think a none flight SABRE engine will be completed, if only to show just what can be accomplished with pre-cooler technology for many other applications.

Offline The Amazing Catstronaut

  • Full Member
  • ****
  • Posts: 1071
  • Arsia Mons, Mars, Sol IV, Inner Solar Solar System, Sol system.
  • Liked: 755
  • Likes Given: 628
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1367 on: 03/19/2016 10:07 PM »
Better just the pre-cooler than nothing. If the technology is picked up elsewhere and used for other applications, seeing another Skylon-esque project develop a decade down the road becomes increasingly more likely, and the team will have less of a money pile to climb for it.

Anything that enables high speed hypersonics is useful for designing similar airbreathing SSTOs. Certainly Skylon will inspire other SSTO designs for a long time coming.
Resident feline spaceflight expert. Knows nothing of value about human spaceflight.

Offline alanr74

  • Member
  • Posts: 5
  • uk
  • Liked: 1
  • Likes Given: 1
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1368 on: 03/20/2016 12:04 AM »
t43562
**I remember the point at which 2-300 million seemed to be apparently lined up if I understood it right**

That's what a lot of us seemed to think, but to be honest that might just have been ourselves seeing things where there was nothing. REL never said such a thing.

But as you say, they've hung on until now by the skin of their teeth. The BAE buy-in was a surprise (to me at least) and although REL may welcome the money and profile BAE bring with them, it did seem rather cheap for the percentage stake that BAE got. It seems like they were down to few options with financial and commercial realities beginning to bite.

From the looks of things now, I would guess that Skylon, as originally imagined by Alan Bond and Co, is dead in the water. I'd guess that the Sabre tech is first going to appear in a USAF project.

Cheap! I would say BAE possibly overspent. It's basically a massive risk, way to far in the future and could be out of date before it's born.

If anything BAE, RR (in kind) and the UK government are all part of keeping it afloat enough to make the project viable. hell even the Americans are taking an interest because there are possibilities for it.


Online t43562

  • Full Member
  • *
  • Posts: 172
  • UK
  • Liked: 72
  • Likes Given: 37
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1369 on: 03/20/2016 06:59 AM »

From the looks of things now, I would guess that Skylon, as originally imagined by Alan Bond and Co, is dead in the water. I'd guess that the Sabre tech is first going to appear in a USAF project.

I didn't mean to set off a round of pessimism! I think that it's underestimating them to imagine that they haven't got their goal in sight all the time.   It just think that the path from here to there might have to pass through various stopovers.

Offline Radical_Ignorant

  • Member
  • Posts: 68
  • Liked: 14
  • Likes Given: 114
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1370 on: 03/20/2016 09:00 AM »
And I'm not talking about "tech demonstrators", I'm talking about productive versions that reduce the development costs for each step.
Hard to disagree. Just I have problems to see how TSTO would simplify, make development cheaper, less risky and still competitive if all advantage of this system is to use different approach and as they say it's not down scalable.
Space X took proven technology, so it worked for them. How this approach could work for REL? Let's build engine and sell it? It's what they try to do - correct me if I'm wrong. Let whoever have any desire buy it and pay them cash so they can think of making Skylon or even not - maybe someone else will do Skylon or something different.

Secondly, there is what Zurbin is arguing against: let's do multiple middle steps. Let's push the final goal so far away that till this time will come, everything will change.

How's that worked out for Zubrin so far? He's now notorious for handwaving any problems in his own proposals while attacking any alternatives, to the point that I doubt anyone except a few rusted-on fanbois¹ take him at all seriously any more.

The most he's achieved is to reduce support for other technology development programs.

¹ Of course, one of those fanbois now owns his own rocket company. But ironically he practices the iterative development method I prefer.
That's not fair. What progress NASA achieved in their goals to go to moon and Mars and... Other tech programs, like VASIMIR, which is, as far as I read abut it, over promised even in theory. Additionally that was the goal of Zurbin to "don't waste resources on unknown purpose technology". Addionally that he is little aggressive and unfriendly in manner of his speeches have nothing to do with validity of his arguments.

How many projects with approach let's-first-develop-demonstrator were never continued because of, "nah, we are not interested in this anymore" from politicians.

Far fewer than have overpromised and underdelivered, and consumed way too much money chasing a technological mirage before being cancelled.
OK - that makes no sense. We could argue for ages about methodology how to count it. There are lot of examples when each approach worked and as well multiple examples for opposite.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 5891
  • Everyplaceelse
  • Liked: 749
  • Likes Given: 4556
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1371 on: 03/20/2016 10:49 AM »
True. I think SSTOs would have a much stronger case if we had space tugs.

However, with electric propulsion now being available to raise satellite orbits...
The biggest change in REL's development plans was the introduction of the Skylon Upper Stage, which is a reusable space tug
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Online Hankelow8

  • Full Member
  • *
  • Posts: 155
  • UK
  • Liked: 112
  • Likes Given: 40
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1372 on: 03/20/2016 11:21 AM »
True. I think SSTOs would have a much stronger case if we had space tugs.

However, with electric propulsion now being available to raise satellite orbits...
The biggest change in REL's development plans was the introduction of the Skylon Upper Stage, which is a reusable space tug

Without the upper stage  "space tug" Skylon would have been a none starter from the beginning. It's low orbit would have been of no use to the vast majority of it's prospective clients.
« Last Edit: 03/20/2016 11:31 AM by Hankelow8 »

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 5891
  • Everyplaceelse
  • Liked: 749
  • Likes Given: 4556
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1373 on: 03/20/2016 12:11 PM »
Skylon needs billions and who is going to provide them? I can see his feeling that REL have survived by the skin of their teeth, have a bit more time thanks to BAE and eventually HMG but they have most of the mountain still to climb.  So I am sure they will do whatever anyone else will pay them to do as I think they did with the Lapcat project.   
REL are still waiting for the £60m promised over 2 years by George Osborne in 2014.


I don't think they've ever been interested in the manufacture of the actual spaceplane (are they called space planes?). It's always been about the engine as to build the actual spaceplane and the engine would be something that is just not feasible.
Historically it was REL's plan to just build the pre cooler for the enging.

However as size a company has to be to be able to handle complex tasks has shrunk they've realized they could make the whole engine as well.

REL's goal was always to form a consortium around the idea of building a spaceplance with Skylon as their model. The consortium could come up with a new design but REL aimed to deliver a design well enough thought out to get the consortium to go with it
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 5891
  • Everyplaceelse
  • Liked: 749
  • Likes Given: 4556
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1374 on: 03/20/2016 12:12 PM »
Cheap! I would say BAE possibly overspent. It's basically a massive risk, way to far in the future and could be out of date before it's born.
Yes it's true BAE don't like risk.

They like their money from nice safe cost plus projects like Typhoon.

How many decades it take to go from signing the contract to getting a single vehicle to RAF service?
Quote
If anything BAE, RR (in kind) and the UK government are all part of keeping it afloat enough to make the project viable. hell even the Americans are taking an interest because there are possibilities for it.
Or perhaps it's because when REL have been adequately funded they have delivered what they said they could when they said they would?


That's precisely why trying to jump directly to a multi-billion Pound/Euro design seems so unlikely.

And I'm not talking about "tech demonstrators", I'm talking about productive versions that reduce the development costs for each step.
Skylon's (and hence SABRE's) size is the way it is because REL looked at the market and asked people what they wanted to meet their needs. This is the size that came back.
Quote
How many projects with approach let's-first-develop-demonstrator were never continued because of, "nah, we are not interested in this anymore" from politicians.

Far fewer than have overpromised and underdelivered, and consumed way too much money chasing a technological mirage before being cancelled.
A near perfect description of the X30 programme.

Which was REL asked ESA to perform an independent assessment of what they are planning and how. Something AFAIK no other company has done to demonstrate conclusively that what they are proposing is viable
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline Paul451

  • Full Member
  • ****
  • Posts: 1238
  • Australia
  • Liked: 607
  • Likes Given: 520
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1375 on: 03/20/2016 04:29 PM »
I have problems to see how TSTO would simplify, make development cheaper, less risky and still competitive

A TSTO would still be too many steps at once, IMO. But more generally, TSTO would lower risk by reducing both the top speed required and the re-entry forces it has to cope with to allow low-cost reuse. (Remember, it's not just thermal effects.) Also, by reducing the demands on the airframe, by increasing the engineering margins, you lower the development costs.

But to clarify: most of my criticism isn't aimed at REL, but at their fanbois. I'm sure REL would be happy to work on a TSTO. Hell, even developing a version of the pre-cooler for stationary generator gas turbines. It's the fanbois not REL itself who are screeching that any alternative proposal is "wrong" or "stupid", even when those proposing it are holding money.

I do think that in the early years, REL pushed Skylon too heavily and that actually harmed their ability to attract interest. It created the perception that they weren't open to other ideas: "We have this product that can only be used on one extremely high risk, extremely costly development. Plz send ur monies." More recently, they seem to have opened up to other concepts (or at least changed the perception) and correspondingly, interest from potential investors has increased. Both investors and potential customers tend to avoid overly-obsessive inventors because they will be blind to alternative business opportunities and be high-maintenance to work with. There's a difference between enthusiastic and monomaniacal. One is hard working, the other is hard to live with. Surely you've noticed that in your own life? You tend to avoid working with shouty-obsessive types, even when they are otherwise skilled and useful.

JohnSmith19,
Make up your mind. One minute the technology itself is inherently unscalable, the next it's scaled that way only to fit the requirements of the client.

Offline 93143

  • Senior Member
  • *****
  • Posts: 3039
  • Liked: 292
  • Likes Given: 1
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1376 on: 03/21/2016 12:15 AM »
The technology is scalable.  Last time I asked, REL had not run into any upper limit, and there's no real reason you couldn't make it a bit smaller if that would fit the market better.

But if you try to make it a lot smaller, you run into problems.  Alan Bond has noted that a subscale development engine like the one they were planning originally would have issues with the extreme speed of the hydrogen turbopump (~300krpm or something), which would cost quite a bit to develop.  Hence their eagerness to go to full scale on the engine prototype when it looked like they'd have a chance to do so.

Offline 93143

  • Senior Member
  • *****
  • Posts: 3039
  • Liked: 292
  • Likes Given: 1
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1377 on: 03/21/2016 02:06 AM »
https://imgur.com/a/F87pA

...oh hey.  They've got new graphs based on the ones in Varvill & Bond (2003).  And SABRE 4 (as expected) performs vastly better than SABRE 2/3 - the shape of the Isp curve is similar, but this one peaks near 6000 seconds instead of a little past 3000.  And it's missing the hole around Mach 1; the peak is thus closer to Mach 1.3 or so rather than Mach 2.
« Last Edit: 03/21/2016 03:38 AM by 93143 »

Offline Citizen Wolf

  • Full Member
  • *
  • Posts: 158
  • Milky Way, Western spiral arm
  • Liked: 27
  • Likes Given: 26
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1378 on: 03/21/2016 09:07 AM »
@93143
I totally missed that the graph was referring to Sabre 4. Thanks for pointing that out. I know we all pretty much guessed that they were going to go with Sabre 4, AFAIK no official announcement has been made yet, but I guess going from that graph the decision has been made for Sabre 4.
The only thing I can be sure of is that I can't be sure of anything.

Online t43562

  • Full Member
  • *
  • Posts: 172
  • UK
  • Liked: 72
  • Likes Given: 37
Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1379 on: 03/21/2016 10:59 AM »
@93143
I totally missed that the graph was referring to Sabre 4. Thanks for pointing that out. I know we all pretty much guessed that they were going to go with Sabre 4, AFAIK no official announcement has been made yet, but I guess going from that graph the decision has been made for Sabre 4.

It is interesting that in that talk he made no mention of the fact that the frost control system was probably not going to be needed and mentioned that one person nearly let out the secret of it without pointing out that the patents are public and the secret is revealed anyhow.   So why have the talks have continued following the "SABRE3" story?  One reason could be that it allows them to give an interesting talk, impress everyone etc without giving away too much about their current train of thought.

With regard to publicising talks, I can well imagine that they are not interested in publicity *that much* and are doing them for the money. If so it's a bit sad. I think fanbois are future shareholders :-)



Tags: