Author Topic: The Reaction Engines Skylon Master Thread (5)  (Read 420360 times)

Offline ChrisWilson68

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #40 on: 02/20/2015 06:36 PM »
But "my" point still stands that by the criteria Chris used, SpaceX was an "unproven" company despite all their "incremental" testing until they actually flew a successful, full-up flight :)

Yes, I agree, SpaceX was at one time an unproven company.  If we were back at the time before SpaceX had built and tested its first engine and SpaceX were making projections about how many cycles their reusable first-stage airframe could handle, I would say they didn't have enough information to be making projections like that and that such projections shouldn't be considered reliable.  In fact, back then SpaceX thought that they would be reusing their first stages by putting parachutes on them, covering them with cork, and fishing them out of the sea.  They even made their first engines salt-water-tolerant because of that plan.  And that's exactly my point -- a company that has yet to build its first engine has a lot of unknowns in front of it.

SpaceX took a much more incremental approach, and that allowed them to learn lessons and modify their approach.  Their approach was also much less of a leap beyond the existing state of the art at the time.  That allowed them to deal with all those unknowns.  What worries me about REL is that they seem to think they know most of the unknowns already, when I don't think they -- or anyone else -- possibly could.

Offline SICA Design

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #41 on: 02/20/2015 06:50 PM »
Denigrating the hard work by done by people trying for the same goal but by different means.

If by the "same goal" you mean fully-reusable, wasn't this JS19's point; to compare SABRE/Skylon with others also aiming for fully-reusable vehicles (with ELV-like payload fraction). I follow every post on this thread (5-off), and have seen little (if any) denigration of others' hard work.

Edit: Substituted "fully-reusable" for "SSTO"
« Last Edit: 02/20/2015 06:57 PM by SICA Design »

Offline ChrisWilson68

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #42 on: 02/20/2015 06:55 PM »
i don't understand the animosity toward REL.

I haven't seen any evidence of animosity toward REL.  None.  I specifically said I hope they do succeed.

Skepticism is not the same as animosity.

The only animosity I've seen is between posters on this forum.

Skepticism is healthy.  People should welcome it even if they disagree.  Skepticism helps make sure the right decisions are made and makes it more likely we move forward in spaceflight, just like we all want.

what have they done to offend so?

Nothing at all.  Why do you interpret skepticism as offense?

to me REL brings to mind two things -  the sentiment behind the quote “We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard."   and  Concorde.

The worry is in fact that REL will turn into another Concorde -- a waste of money and talent on a system that was not economically viable.

If you visit the Hiller Aviation Museum in San Carlos, California, you can see a large section of the front of what looks a lot like Concorde.  It was actually built by Boeing, at the same time Concorde was under development.  The Boeing program was going well and they could have completed their own supersonic airliner.  But they cancelled the project because they judged it wouldn't be economically feasible.  Boeing was right.  By cancelling that project, they freed up resources and engineering talent for other projects that benefited the aerospace industry.

If you read my earlier post carefully, you would realize I wasn't calling for the cancellation of the technology REL is trying to develop.  I was instead suggesting more caution in projections and a more flexible, incremental development approach.

REL are working really hard on a disruptive idea that they had; one that they think can achieve the same as elon musk's goal of cheap rapid access to space for the benefit of mankind. good for them. that should inspire, not generate a load of naysaying.  what's wrong with you people?

I find it very sad that you interpret well-intentioned skepticism as being a character flaw.  Even if you disagree with our skepticism, why can't you accept that it comes from good intentions?

when the space shuttle idea was proffered, did people say 'what's wrong with normal rockets?, we know how to do normal rockets'  were there naysayers arguing for incremental steps?  i don't know.  the result was awesome.   

A discussion of the Space Shuttle is off topic for this thread, but suffice it to say there are many people who think the Space Shuttle program was a mistake and a more incremental approach that didn't try to do so much would have been a better use of resources.  Many people think the space shuttle kept of stuck in Low Earth Orbit for decades when we could have been exploring far beyond.

' what's wrong with normal aeroplanes?'   and then out rolls concorde.  if there were people at the time who tried to undermine the spirit of the project,  i bet they were as awestruck as the rest of us when the result took off in front of them.

the world has been mesmerised by  spacex landing rockets and capsules; by them constructing a BFR,  and then out rolls Skylon sounding like the end of the world.   how is this bad?  if it is difficult, if it takes a long time, are they reasons for REL to give up?  of course not.  the world needs passionate and competent innovators of their ilk.  they should be encouraged.  i wonder if this thread is getting REL down. i hope not.

Blind encouragement and ignoring potential mistakes is ultimately bad for any project.  True friends are honest, even if they have to say things people don't want to hear.

Offline RanulfC

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #43 on: 02/20/2015 06:57 PM »
LarsJ, Do I then assume that you deride the various "Fully-reusable TSTO is a done deal" SpaceX fans the same way? :)

No Skylon is FAR from a "done-deal" but it does have many features and abilities that are inherent to its nature if it works even remotely close to what its supposed to. I am as hopeful as you are that it works but well aware of the numerous "risks" still to be retired. On the other hand I'm also a SpaceX supporter though I will admit (as many won't) the various and sundry short-comings inherent in the design and principles of that vehicle/design.

"Comparing" the two is frustratingly common and misleading as I've pointed out before.

Skepticism is to be expected for it can be overcome with education and data. (Not to mention working hardware :) ) And yes Skylon is the latest in a long line of "promising" SSTO vehicle but I'd point out that it in fact is much close to, and much easier to implement than most where and does not (at this point) really need as significant technologies as most of the previous concepts did. The two biggest hurdles technology wise were the heat exchanger and the rocket motor both of which have been demonstrated. A full size working engine is next and really that's simply engineering the various components together and there's quite a bit of "prior-history" for that.

Impaler, not sure if you really want to be labeled as a 'detractor' as most here who actively engage in it have to rely on arguing the business case rather than technical details :) I'll admit to some trepidation on the assumptions involved but they DO actually have a historic (aircraft) model to draw on. Doubts are common and normally a good thing as long as they are not carried too far :)

I understand that many folks have differing ideas on how REL "should" proceed from this point but really a full size engine IS the next step. After that...

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline Kansan52

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #44 on: 02/20/2015 06:59 PM »
Thanks Randy. That summary really helps me!!

Offline RanulfC

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #45 on: 02/20/2015 07:08 PM »
Yes, I agree, SpaceX was at one time an unproven company.  If we were back at the time before SpaceX had built and tested its first engine and SpaceX were making projections about how many cycles their reusable first-stage airframe could handle, I would say they didn't have enough information to be making projections like that and that such projections shouldn't be considered reliable.  In fact, back then SpaceX thought that they would be reusing their first stages by putting parachutes on them, covering them with cork, and fishing them out of the sea.  They even made their first engines salt-water-tolerant because of that plan.  And that's exactly my point -- a company that has yet to build its first engine has a lot of unknowns in front of it.

I'm going to point out that the bolded part is NOW not "back-then" as SpaceX does NOT have the data to make accurate predictions... yet.

Yes REL faces a lot of "unknowns" in assembly of their first engine but the basic technology and techniques are already in place. They have already retired two of the biggest with the heat exchanger and rocket. Their biggest hurdle continues to be money, not competence or capability. Where would SpaceX be without Musk and his money?

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SpaceX took a much more incremental approach, and that allowed them to learn lessons and modify their approach.  Their approach was also much less of a leap beyond the existing state of the art at the time.  That allowed them to deal with all those unknowns.  What worries me about REL is that they seem to think they know most of the unknowns already, when I don't think they -- or anyone else -- possibly could.

Which unknowns would those be? I'm curious.

SpaceX's approach was highly conservative in most respects. They built an ELV with the idea of eventually turning it into an RLV. They then rebuilt it as an RLV but still usable as an ELV. In the end its going to remain an RLV that "can" be an ELV and in that sense its limited (and they admit this) and eventually will end up a "dead-end" no matter how successful. But it's a start and in the right direction so kudos and I'm rooting for them.

REL is aiming for a different vehicle, operational mode, and model from the start and they have far less resources than SpaceX did to do it with. That in no way makes one approach "better" than the other.

Randy
« Last Edit: 02/20/2015 07:09 PM by RanulfC »
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline ChrisWilson68

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #46 on: 02/20/2015 07:23 PM »
Yes, I agree, SpaceX was at one time an unproven company.  If we were back at the time before SpaceX had built and tested its first engine and SpaceX were making projections about how many cycles their reusable first-stage airframe could handle, I would say they didn't have enough information to be making projections like that and that such projections shouldn't be considered reliable.  In fact, back then SpaceX thought that they would be reusing their first stages by putting parachutes on them, covering them with cork, and fishing them out of the sea.  They even made their first engines salt-water-tolerant because of that plan.  And that's exactly my point -- a company that has yet to build its first engine has a lot of unknowns in front of it.

I'm going to point out that the bolded part is NOW not "back-then" as SpaceX does NOT have the data to make accurate predictions... yet.

Yes, they don't have the data to be fully confident.  It's still somewhat uncertain.  But having actually designed, built and flown real stages, done water landings, flown Grasshopper and F9R-dev1 in Texas, they do have some data to go on.  They have done enough to be far, far more confident about how many times they can re-use it than REL.

Yes REL faces a lot of "unknowns" in assembly of their first engine but the basic technology and techniques are already in place. They have already retired two of the biggest with the heat exchanger and rocket. Their biggest hurdle continues to be money, not competence or capability. Where would SpaceX be without Musk and his money?

True, Musk was an asset to SpaceX without a doubt.  But he had $100 million to invest.  REL says they need more than 100 times that amount of money.

REL needs both investors and a cheaper program to have a better shot at actually succeeding.

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SpaceX took a much more incremental approach, and that allowed them to learn lessons and modify their approach.  Their approach was also much less of a leap beyond the existing state of the art at the time.  That allowed them to deal with all those unknowns.  What worries me about REL is that they seem to think they know most of the unknowns already, when I don't think they -- or anyone else -- possibly could.

Which unknowns would those be? I'm curious.

They are all the things that aren't anticipated in advance that are learned when doing the detailed design and when doing flight tests of that design.

SpaceX's approach was highly conservative in most respects. They built an ELV with the idea of eventually turning it into an RLV. They then rebuilt it as an RLV but still usable as an ELV. In the end its going to remain an RLV that "can" be an ELV and in that sense its limited (and they admit this) and eventually will end up a "dead-end" no matter how successful.

Huh?  That makes no sense to me.  Because it can be used as either an expendable or reusable vehicle it's a dead end?  Just because it can be used as expendable doesn't mean it's any less effective as a reusable vehicle.

But it's a start and in the right direction so kudos and I'm rooting for them.

REL is aiming for a different vehicle, operational mode, and model from the start and they have far less resources than SpaceX did to do it with. That in no way makes one approach "better" than the other.

The SpaceX approach has so far succeeded.  Past programs that were more like the REL approach have failed.  That's what makes one approach better than the other.

Offline RanulfC

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #47 on: 02/20/2015 07:53 PM »
I haven't seen any evidence of animosity toward REL.  None.  I specifically said I hope they do succeed.

I don't think it's YOU that's being referred to :) I seem to recall at least one post where REL was called an outright 'fraud' which I think would be considered "animosity".

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Skepticism is not the same as animosity.
Skepticism is healthy.  People should welcome it even if they disagree.  Skepticism helps make sure the right decisions are made and makes it more likely we move forward in spaceflight, just like we all want.

No it's not and in measure its a good thing. However, skepticism focused on "second-guessing" someone who's actually "done-the-math" and bent metal in testing is another level. (One I'm guilty of with SpaceX at times I must admit :) )

And how 'helpful' is skepticism when it is mis-directed and/or non-constructive? Not that it probably actually matters since we're on these forums and both SpaceX and REL would seem to read but not take our "opinions" into their consideration :)
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The worry is in fact that REL will turn into another Concorde -- a waste of money and talent on a system that was not economically viable.

And it's from this "point-of-view" that your argument make no sense :) REL is not Boeing (your example) and if Boeing DOES come on-board at some point they will have made the exact calculations and studies you mention. You seem to assume that "someone" is going to blindly accept REL's figures which hasn't been done by anyone so far as evidenced by the "lack" of investors beating down their door. The "talent and money" they are using is the same ones they started out with and they DON'T have "other" business that they are taking these from. So your 'fear' would seem groundless which makes me suspect its NOT what your really questioning :)
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If you read my earlier post carefully, you would realize I wasn't calling for the cancellation of the technology REL is trying to develop.  I was instead suggesting more caution in projections and a more flexible, incremental development approach.

Got that but you don't seem to understand the limitations on REL due to the technology involved. They ARE being incremental. Unless the SABRE under-performs by a very significant margin their work shows that going with a TSTO design WOULD be un-economical (which is supposedly an underlying concern of yours) compared to a fully SSTO design. If this is "true" then they will find out with the full-up engine demonstrator and thereby adjust their development plans accordingly. (Considering that Mardquart had an Mach-4.5 "almost-flight-weight" LH2/LOX capable RBCC-SERJ engine ready for testing in the early 1960s WITHOUT deep-cooling or an air-fed rocket motor I consider this an unlikely complication)

Again, your "skepticism" seems misdirected.

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I find it very sad that you interpret well-intentioned skepticism as being a character flaw.  Even if you disagree with our skepticism, why can't you accept that it comes from good intentions?

"I" don't consider it a character flaw BTW so we're clear :) But I DO have to wonder at the "intentions" given the circumstances. "Supporters" are being accused of "blind encouragement," "ignoring problems," and "Skylon evangelism" despite real attempts to answer and address questions and skepticism about the concept. Is it perhaps that BOTH sides are missing the point that the discussion comes from "good intentions" on both sides?

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A discussion of the Space Shuttle is off topic for this thread, but suffice it to say there are many people who think the Space Shuttle program was a mistake and a more incremental approach that didn't try to do so much would have been a better use of resources.  Many people think the space shuttle kept of stuck in Low Earth Orbit for decades when we could have been exploring far beyond.

Point here is that the "Space Shuttle" for good or ill IS the only current example of an operational RLV and therefore the "comparisons" no matter how inaccurate are inevitable as well :) Just like comparisons to the F9 seem to be despite the lack of "common-ground" for such :)

(And anyone who even THINKS that it was the Shuttles "fault" we've been stuck in LEO for the last 40+ years is simply looking for an excuse to ignore the real reasons and why those reasons will continue to manifest themselves as long as the "government" is the driving factor)

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Blind encouragement and ignoring potential mistakes is ultimately bad for any project.  True friends are honest, even if they have to say things people don't want to hear.

Yep :) Shall we proceed from that point and continue the discussion friend? :)

Randy
« Last Edit: 02/20/2015 07:54 PM by RanulfC »
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline SteveKelsey

Re: The Reaction Engines Skylon Master Thread (5)
« Reply #48 on: 02/20/2015 08:01 PM »
Maybe it helps to bring it down to the differentiator. REL have delivered a pre-cooler that can enable a new air-fuelled rocket engine. This is a matter of fact, not opinion. The SABRE offers margins that are robust enough to enable reusable SSTO to be considered.
I don't think anyone is suggesting that the pre-cooler is anything other than a breakthrough.
From this breakthrough REL have projected what they believe they can deliver with the technology. There will be many other applications that are easier to deliver than an SSTO but that’s the deliver REL want to make.
Its entirely reasonable to point out that REL have a long way to go, and that the design will mature as learning progresses but just maybe the projections for and against have become a little ....searches for suitably diplomatic term...abstract?
« Last Edit: 02/20/2015 08:02 PM by SteveKelsey »
2001 is running a little late, but we are getting there.

Online Lars-J

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #49 on: 02/20/2015 08:15 PM »

The two biggest hurdles technology wise were the heat exchanger and the rocket motor both of which have been demonstrated.

The rest of your post was reasonable, but this I must inquire about:
When was the rocket motor demonstrated? Did I miss that?

Offline ChrisWilson68

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #50 on: 02/20/2015 08:24 PM »
I haven't seen any evidence of animosity toward REL.  None.  I specifically said I hope they do succeed.

I don't think it's YOU that's being referred to :) I seem to recall at least one post where REL was called an outright 'fraud' which I think would be considered "animosity".

Agreed.  I've never gotten the impression REL is a fraud.  On the contrary, I think the people there are very dedicated to their vision and have chosen to work on it for many years on lean funding in spite of the fact I'm sure they could find more lucrative things to do.

Is it perhaps that BOTH sides are missing the point that the discussion comes from "good intentions" on both sides?

That's a good point.  I think it always helps to assume that even those we disagree with have good intentions.

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Blind encouragement and ignoring potential mistakes is ultimately bad for any project.  True friends are honest, even if they have to say things people don't want to hear.

Yep :) Shall we proceed from that point and continue the discussion friend? :)

Yes! :-)  Skepticism of my skepticism is fair.

I think this particular discussion has more or less run its course.  We've all made our points, and other readers can judge for themselves what they find most persuasive.

I look forward to hearing more news from REL in the future so we have new things to discuss.

Offline SICA Design

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #51 on: 02/20/2015 08:53 PM »

The two biggest hurdles technology wise were the heat exchanger and the rocket motor both of which have been demonstrated.

The rest of your post was reasonable, but this I must inquire about:
When was the rocket motor demonstrated? Did I miss that?

It appears so; there have been a number of nozzle and flow demonstrator engines built and tested by REL and their associates:

STRICT
STERN
STRIDENT
STOIC
STILETTO

http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=33648.0;attach=571189

Offline ChrisWilson68

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #52 on: 02/20/2015 09:35 PM »

The two biggest hurdles technology wise were the heat exchanger and the rocket motor both of which have been demonstrated.

The rest of your post was reasonable, but this I must inquire about:
When was the rocket motor demonstrated? Did I miss that?

It appears so; there have been a number of nozzle and flow demonstrator engines built and tested by REL and their associates:

STRICT
STERN
STRIDENT
STOIC
STILETTO

http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=33648.0;attach=571189

Yes, those are important pieces of hardware being tested.  I think it's fairer to call them engine component tests rather than engines, though.  None is something you could put on a vehicle and have it fly.

Offline ChrisWilson68

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #53 on: 02/20/2015 10:48 PM »
What would people think of separating this thread into two threads: Skylon Updates and Skylon Discussion?  There's been a lot of discussion in the Skylon threads, and not everyone who is interested in hearing about news from Skylon has the time or inclination to follow all the discussion.

Offline lkm

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #54 on: 02/20/2015 11:12 PM »
Just to say Richard Varvil has 2 Lectures coming up:

Tuesday, 14 April Skylon and Sabre - Bringing Space Down to Earth
http://aerosociety.com/Events/Event-List/1934/&

and

Thursday, 21 May The Skylon Spaceplane and Sabre Engine:- progress to date and future prospects’
http://aerosociety.com/Events/Event-List/1640/&

for anyone able to go.

Also on  the 26th of March he's a speaker at this event:

http://www.develop3dlive.com/speakers/

Finally  Alan Bond has a lecture here:
http://www.theiet.org/events/2015/210323.cfm?nxtid=

On the 4th of June called The SKYLON - the future of space transportation
« Last Edit: 02/20/2015 11:20 PM by lkm »

Offline john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #55 on: 02/20/2015 11:53 PM »
I'm interested in what happens assuming they get things mostly right or what they might do if this or that issue turns out to be more difficult  because the alternative is that they go bust and the world is the same as before which is a non-story - why discuss it?
Indeed. Who'd start up a start up expecting to fail?
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We might as well mention that lots of people have built rockets before but this heat exchanger is exceptional so it speaks for their ability to come up with something unheard of and get it done right.
Yes, that's why they built it first.  If they couldn't make this work there was no point in continuing.

The key point is not only that it works but it works as designed which implies they have a deep understanding of how it works.
"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

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #56 on: 02/20/2015 11:54 PM »
The DC-X clearly meets your original point which had no requirement of being in charge or the end system becoming operational. Other projects that meet that criteria plus your newly added one of operational status are the EJ200, Spey and RB211 which Richard Varvill and John Scott Scott worked on, respectively.
For those who don't know these are low and high bypass ratio turbofan engines. The EJ200 powers the Eurofighter Typhoon and is therefor SoA for high T/W ratio engines running over a broad range of thrust and altitude settings.
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When are you proposing to stage this notional TSTO? Inside the atmosphere so you can use a simpler non rocket mode SABRE losing LOX tanks from the first stage or outside still using SABRE?
 Are you carrying the second stage internally or externally? If externally how are managing the damage that does to the aerodynamics and thermal protection? If internal how are making the vehicle trimable given the damage that does?   
What engine is powering the second stage?
How does any of that make the development of SABRE cheaper? Either you're proposing using the SABRE design as is, or you're suggesting development of a second engine, on top of SABRE, without a pure rocket mode neither of which can be cheaper for REL as an engine developer than just building SABRE.
Indeed. It's one of those ideas that sounds very sensible, until you look at it a bit more closely.
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I can't help feel that rocketry (successfully putting things in orbit since 1957)  is somewhat better understood that Scramjets ( someday soon we'll reach ten minutes cumulative flight time). Who is seriously researching scramjets for anything other than hypersonic cruise? Also please name these other people who think that the development challenges of NASP in 1984 are of comparable difficulty to the challenges of Skylon in 2015.
That would be an interesting list.
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Many people believe that VentureStar wasn't viable, but I don't think anybody believes the X-33 couldn't have flown and gathered useful data. The X-33 wasn't VentureStar, VentureStar was a powerpoint, X-33 was an active x-plane project with a similar budget and goals to the X-15. The X-15 wasn't a failure because it had no follow on project so why  should the X-33? When the X-15 first flew it didn't have it's intended engine yet because it wasn't ready, so why should the X-33 not have been given the same leeway? Like I said, there was a change in administration, a desire to cancel and repudiate the projects of the previous one, people obliged.
Actually the view amongst some people was that the X33 was extremely complex and risky for its stated purpose. I'd suggest VTOHL SSTO is the most difficult way to do it. It calls for both a T/W of at least 1.1:1 and a strong structure in two axes.
"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

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #57 on: 02/20/2015 11:55 PM »
EDIT: To offer a more substantive response. I don't think the line between science and engineering exists as you think it does. And what scientific breakthroughs have REL done? Their pre-cooler work would be classified by most as an impressive piece of engineering.
Well for those who are having a little trouble understanding the difference.
If you can look up the numbers or the models in a text book or report (and they produce accurate results IE within an acceptable limit of error) that's Engineering.

When you can't, because either the models are wrong or they simply don't exist then you're doing Science.

REL have practiced Science making the frost control system work. The bulk of the rest is expected to be Engineering.

SpaceX built a TSTO ELV. That's Engineering. 11 years in they have now have to do Science to learn
a)Landing high aspect ratio "floppy" structures b)Rocket ignition in a supersonic flow c) Aerodynamics and control over a wide Mach range using grid fins d) Modelling fluid slosh forces on pairs of very large tanks.

Somewhere along the way they've also discovered that their 2nd plan to do 2nd stage recovery can't be made to work without an unacceptable payload loss, which would indicate some (all ?) of their models were in error.
« Last Edit: 02/21/2015 12:50 AM by john smith 19 »
"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 Impaler

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #58 on: 02/21/2015 12:22 AM »
What your calling Science I would simply call 'real man's engineering' and looking something up from a book is 'engineering for dummies'.  Iteration in engineering doesn't in my opinion make it a science because science is the creation and testing of theories, engineering is the creation and testing of devices.

Offline topsphere

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #59 on: 02/21/2015 12:56 AM »


Also on  the 26th of March he's a speaker at this event:

http://www.develop3dlive.com/speakers/


This is held at my University. I'll try and go - thanks for the heads up!!

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