Author Topic: The Reaction Engines Skylon Master Thread (5)  (Read 440460 times)

Offline Star One

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #820 on: 11/08/2015 05:09 PM »

Subscale models are needed to prove intact vehicle reentry from orbit.

Unless you want to try it with a full scale "reuseable" but really expendable vehicle.

F9R is cheap enough to start from F9 expendable, is Skylon also cheap enough to start from expendable?

They aren't needed if you're interested in building a hypersonic aircraft & not Skylon.

I think people are still thinking that a subscale model is going to be for Skylon when from what BAE are indicating this isn't their initial aim.

Offline adrianwyard

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #821 on: 11/08/2015 05:46 PM »
Are you implying BAe has a hypersonic military aircraft in mind, or a passenger aircraft? If military, what's the end product? I'm having a hard time imagine what strike/reconnaissance capability could justify the cost.

And it's been previously argued that a passenger aircraft is likely much harder to pull off (technically and economically) than an SSTO launcher.

Offline momerathe

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #822 on: 11/08/2015 06:03 PM »
Allan Broad said it would cost £350 to get finished engine. £10B to produce Skylon and engines, I think this is large scale manufacturing.

Going from finished engine to flying prototype Skylon would still cost a few £B.

yup, and nobody's going to lay out that kind of investment without knowing the engine's going to work, because with no engine there's no value proposition.
thermodynamics will get you in the end

Offline Katana

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #823 on: 11/08/2015 06:09 PM »
Reentry of lightweight fuselage = reuseable upperstage, may be more profitable than SSTO itself.

Anyway, if SSTO success but reuse fails, it's still benificial to reuse only engines and leave fuselage in orbit, docking with ISS, and modify into large diameter habitat.
Are you implying BAe has a hypersonic military aircraft in mind, or a passenger aircraft? If military, what's the end product? I'm having a hard time imagine what strike/reconnaissance capability could justify the cost.

And it's been previously argued that a passenger aircraft is likely much harder to pull off (technically and economically) than an SSTO launcher.

Offline Star One

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #824 on: 11/08/2015 06:23 PM »

Are you implying BAe has a hypersonic military aircraft in mind, or a passenger aircraft? If military, what's the end product? I'm having a hard time imagine what strike/reconnaissance capability could justify the cost.

And it's been previously argued that a passenger aircraft is likely much harder to pull off (technically and economically) than an SSTO launcher.

Well if you read the article posted up thread it sounds like they are very interested in point to point transport.

There seems to be a renewed interest in high speed passenger transport. Hence NASA & its quiet boom technology demonstrator to combat one of the main barriers to supersonic transport that of noise.

Offline adrianwyard

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #825 on: 11/08/2015 06:34 PM »
Which one? The CNN, FT, and Forbes coverage follow the same pattern: REL talk up SSTO launch, but the press wants to talk about passenger travel, REL agree that's enabled by their technology, but if allowed, state that's not their first priority, and that it's harder than space launch.

Am I missing another article? Or missing a quote in these that suggests point-to-point is the new raison d'être?

Offline 93143

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #826 on: 11/08/2015 09:11 PM »
Orbital reentry of razor-thin tank airframe is something with "razor-thin margins".

Unless somebody reentry and reuse an upperstage before Skylon.

No matter with engines.

You don't sound like you're familiar with their structure and TPS concept.  It's not a "tank airframe".  The insulated aluminium cryo tanks are suspended inside a truss that provides the fuselage's stiffness and strength (safety factor 1.5 last I heard) made of titanium composite struts (they've already manufactured test struts; before they'd done that the baseline was ordinary CFRP) and titanium nodes, with multilayer foil underneath a flexible corrugated reinforced glass-ceramic skin (from a company in France; last I heard they were working with REL to get the specs up to those of the AEA's defunct System 2).  High-temperature areas use some form of carbon-carbon composite, like on Shuttle or X-37 (note that the X-37 uses much stronger ACC vs. the Shuttle's RCC, and REL knows this).  Heat soak is handled partly by residual hydrogen fuel.  Reentry simulations have indicated a slightly milder thermal environment than REL had been designing for, suggesting that they may not need active cooling at a certain point on the wing leading edge.  They still plan to use sweat cooling to protect the canard-fuselage interface.
« Last Edit: 11/08/2015 09:36 PM by 93143 »

Offline flymetothemoon

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #827 on: 11/09/2015 02:10 AM »
Allan Broad said it would cost £350 to get finished engine. £10B to produce Skylon and engines, I think this is large scale manufacturing.

The name's Bond. ALAN Bond.

Offline Katana

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #828 on: 11/09/2015 02:47 AM »
Weight must be kept low, similar to Shuttle ETs, so the thickness of structure and TPS are still limited hard.

No orbital RV of this kind have proved successful before. If it proved sucessful, reuesable upperstage also becomes successful, more competition of conventional TSTO rockets with SSTO.

Offline ChrisWilson68

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #829 on: 11/09/2015 02:56 AM »
An one person above mention costs. Cost per flight is expected to be just 5 million quid, they add 5 million for cost of acquiring Skylon presuming it will still cost 1 billion per unit but I suspect prices there will full as they introduce more 3d printed components,  and they could add another 5 for their profit and still be less than half the price of Falcon 9 whilst potentially being a lot more flexible in the missions it is able to carry out.

You're comparing RELs projected cost goals after a long, expensive development program to SpaceX costs today.  Surely it makes more sense to compare RELs projected future costs against SpaceX projected future costs.

Shotwell told a satellite industry conference SpaceX is targeting $5-8 million per launch long term.  That's the number to compare Skylon to.

Offline adrianwyard

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #830 on: 11/09/2015 03:36 AM »
An one person above mention costs. Cost per flight is expected to be just 5 million quid, they add 5 million for cost of acquiring Skylon presuming it will still cost 1 billion per unit but I suspect prices there will full as they introduce more 3d printed components,  and they could add another 5 for their profit and still be less than half the price of Falcon 9 whilst potentially being a lot more flexible in the missions it is able to carry out.

You're comparing RELs projected cost goals after a long, expensive development program to SpaceX costs today.  Surely it makes more sense to compare RELs projected future costs against SpaceX projected future costs.

Shotwell told a satellite industry conference SpaceX is targeting $5-8 million per launch long term.  That's the number to compare Skylon to.

$5-8M including an expendable upper stage?

Offline ChrisWilson68

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #831 on: 11/09/2015 04:04 AM »
An one person above mention costs. Cost per flight is expected to be just 5 million quid, they add 5 million for cost of acquiring Skylon presuming it will still cost 1 billion per unit but I suspect prices there will full as they introduce more 3d printed components,  and they could add another 5 for their profit and still be less than half the price of Falcon 9 whilst potentially being a lot more flexible in the missions it is able to carry out.

You're comparing RELs projected cost goals after a long, expensive development program to SpaceX costs today.  Surely it makes more sense to compare RELs projected future costs against SpaceX projected future costs.

Shotwell told a satellite industry conference SpaceX is targeting $5-8 million per launch long term.  That's the number to compare Skylon to.

$5-8M including an expendable upper stage?

She didn't say, but presumably no, that would be with a reusable upper stage.

SpaceX has said they're not working on a reusable upper stage right now, but they've always said it's their long-term plan.

SpaceX seems to want to grow the market first with somewhat lower costs with first-stage reuse, then later introduce upper stage reuse to lower costs more.  At the flight rate it would take to make Skylon meet its targets, there would be more than enough incentive for SpaceX to make a reusable upper stage.

Offline Star One

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The Reaction Engines Skylon Master Thread (5)
« Reply #832 on: 11/09/2015 08:20 AM »
Which one? The CNN, FT, and Forbes coverage follow the same pattern: REL talk up SSTO launch, but the press wants to talk about passenger travel, REL agree that's enabled by their technology, but if allowed, state that's not their first priority, and that it's harder than space launch.

Am I missing another article? Or missing a quote in these that suggests point-to-point is the new raison d'être?

Yes you are missing an article because it is this one.

http://fortune.com/2015/11/06/bae-commercial-space-launch/


Quote
“This could fundamentally change the way aerospace works,” says Chris Allam, engineering director for BAE’s aerospace business. If the technology works as designed, he says, it could spawn a new breed of aircraft engines capable of much higher speeds and performance.

"A lot of people are excited about point-to-point travel at the moment, the thought of going anywhere in the world in four hours just excites people,” he says. “But that is hugely challenging, it’s just orders of magnitude more difficult. I was telling someone from Australia recently that, unfortunately, it’s more difficult to get to Australia than it is to get into space.”

By the way the fact that the media are more interested in high speed passenger transport than access to space should tell you something alone about where public interest maybe is.
« Last Edit: 11/09/2015 08:41 AM by Star One »

Offline SICA Design

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #833 on: 11/09/2015 01:55 PM »

Yes you are missing an article because it is this one.

http://fortune.com/2015/11/06/bae-commercial-space-launch/


Quote
“This could fundamentally change the way aerospace works,” says Chris Allam, engineering director for BAE’s aerospace business. If the technology works as designed, he says, it could spawn a new breed of aircraft engines capable of much higher speeds and performance.

"A lot of people are excited about point-to-point travel at the moment, the thought of going anywhere in the world in four hours just excites people,” he says. “But that is hugely challenging, it’s just orders of magnitude more difficult. I was telling someone from Australia recently that, unfortunately, it’s more difficult to get to Australia than it is to get into space.”

Hardly an authoritative article:
Quote
“The engine would then transition to rocket power to propel the aircraft to space. On its return journey the aircraft could then transition back to jet power and land like a traditional jetliner on a conventional runway."

Online john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #834 on: 11/09/2015 02:25 PM »
Orbital reentry of razor-thin tank airframe is something with "razor-thin margins".
Welcome to the forum.

The point of the SABRE/Skylon architecture is to make those margins quite wide and hence the design is much more tolerant of small miscalculations in mass and insulation properties.

Let me suggest you read more about SABRE and Skylon before you post again, since you're making assumption s about what is and is not necessary that are simply wrong.

SABRE's benefits to an RLV design, especially an HTOHL like Skylon have been discussed at considerable length within these threads, starting with the expected 2 tonne payload superiority of a Skylon over a (semi) reusable F9.
« Last Edit: 11/09/2015 02:28 PM 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.

Online john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #835 on: 11/09/2015 03:21 PM »
It is intended to be certified like an airplane, with an extensive test programme putting two prototypes through hundreds of flights including dozens of abort tests,
And Dragon can do exactly the same thing.

Wow.  ::)

Just wow.

Leaving aside the fact you are conflating launch vehicle with payload AFAIK the most times a capsule has been flown is twice, in the Gemini programme.

So where have SX or Musk said they can do 100s of  cycles, or have stated that they are committed to hundreds of flight per capsule?

There is no experience of flying a capsule more than 2 times to orbit and no idea (outside SX's data files) how close launch and landing stresses push the capsule to structural failure.

That does not make your claim impossible. Merely that there is virtually no experience of doing it and it has never been a design goal, so it's unclear how close to the ultimate tensile limits (rather than the elastic limits) of materials they push current capsule designs.

OTOH A winged vehicle has done 39 flights to and from orbit. Long haul airliners are targeted at 35000 pressurization/depressureization cycles and short hauls 110 000.

So Skylon, at 0.5% of the number of a modern long haul, sounds conservative enough to be quite achievable.

An one person above mention costs. Cost per flight is expected to be just 5 million quid, they add 5 million for cost of acquiring Skylon presuming it will still cost 1 billion per unit but I suspect prices there will full as they introduce more 3d printed components,  and they could add another 5 for their profit and still be less than half the price of Falcon 9 whilst potentially being a lot more flexible in the missions it is able to carry out.

You're comparing RELs projected cost goals after a long, expensive development program to SpaceX costs today.  Surely it makes more sense to compare RELs projected future costs against SpaceX projected future costs.

Shotwell told a satellite industry conference SpaceX is targeting $5-8 million per launch long term.  That's the number to compare Skylon to.

$5-8M including an expendable upper stage?

She didn't say, but presumably no, that would be with a reusable upper stage.
Your memory seems to be failing. Let me refresh it.

Shotwell said this in 2013 in her Keynote speech at Singapore Satellite Forum 2013
Available courtesy of Trent's fine work   here

Her $60m launch price tag clearly references the F9.

2014 Sept 25th. Elon Musk states stage 2 reuse of F9 "uneconomic" and full reusability will only be possible with next generation (BFR) hardware. This is an effect of the environment, not the actual root cause of why it cannot be made economic.  SX remain highly secretive about what that is.

This is where he said it
at around 14:20.
Quote
SpaceX has said they're not working on a reusable upper stage right now, but they've always said it's their long-term plan.
IOW for payloads in the 100 tonne+ category, with a suitably larger base price, Never for an F9 sized vehicle. That is simply dead. Musk made that clear when he said roughly "No reusable upper stages will be based on F9 hardware."
Quote
SpaceX seems to want to grow the market first with somewhat lower costs with first-stage reuse, then later introduce upper stage reuse to lower costs more.  At the flight rate it would take to make Skylon meet its targets, there would be more than enough incentive for SpaceX to make a reusable upper stage.
No one knows if the at lowered price will be low enough to grow the market at all, given the cost of the new 2nd stagy you have to stick on at every launch.

But you know this already, so why do keep up this misinformation?
« Last Edit: 11/10/2015 09:39 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 Katana

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #836 on: 11/09/2015 03:37 PM »
Payloads are usually 10x more expensive than launch services...simply reducing launch cost won't stimulate market size effectively, unless extremely low cost to enable different market structure.

Offline adrianwyard

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #837 on: 11/09/2015 04:11 PM »
Which one? The CNN, FT, and Forbes coverage follow the same pattern: REL talk up SSTO launch, but the press wants to talk about passenger travel, REL agree that's enabled by their technology, but if allowed, state that's not their first priority, and that it's harder than space launch.

Am I missing another article? Or missing a quote in these that suggests point-to-point is the new raison d'être?

Yes you are missing an article because it is this one.

http://fortune.com/2015/11/06/bae-commercial-space-launch/


Quote
“This could fundamentally change the way aerospace works,” says Chris Allam, engineering director for BAE’s aerospace business. If the technology works as designed, he says, it could spawn a new breed of aircraft engines capable of much higher speeds and performance.

"A lot of people are excited about point-to-point travel at the moment, the thought of going anywhere in the world in four hours just excites people,” he says. “But that is hugely challenging, it’s just orders of magnitude more difficult. I was telling someone from Australia recently that, unfortunately, it’s more difficult to get to Australia than it is to get into space.”

By the way the fact that the media are more interested in high speed passenger transport than access to space should tell you something alone about where public interest maybe is.

Thanks. Actually I had read that one (and mistakenly referred to it as Forbes rather than Fortune.) I think Allam's quote and your comment speak for themselves, so won't add much more other than to say you are right that the public are perennially interested in shorter journey times (if there's no other cost) but we're also interested in time travel, miracle weight loss, and cures for the common cold.

Given what we know about the tech and business (limited) my guess is that despite high public interest in point-to-point, BAE may not prioritize a project that Allam (their engineering director for aerospace business) considers "orders of magnitude harder than space launch." But I could be wrong.  :)

Offline Hanelyp

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #838 on: 11/09/2015 04:46 PM »
Payloads are usually 10x more expensive than launch services...simply reducing launch cost won't stimulate market size effectively, unless extremely low cost to enable different market structure.
Payloads are expensive driven by demand to get mass down and reliability up, and by no economy of production scale.  If launch costs and delays drop to where launching a replacement isn't such a big deal, there are economies than can be had in the payloads.  Getting the delay to launch a payload down may be a bigger driver here than reducing price.

Online john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #839 on: 11/10/2015 09:56 AM »
Payloads are usually 10x more expensive than launch services...simply reducing launch cost won't stimulate market size effectively, unless extremely low cost to enable different market structure.
Payloads are expensive driven by demand to get mass down and reliability up, and by no economy of production scale.  If launch costs and delays drop to where launching a replacement isn't such a big deal, there are economies than can be had in the payloads.  Getting the delay to launch a payload down may be a bigger driver here than reducing price.

There is a small amount of cost data on this subject.

Both the GPS and Iridium programmes needed quite large constellations of satellites. IIRC Iridium hired the man responsible for highly automating mfg of the Macintosh computers. Changed the design to simplify assembly and from memory cut build time by 50%.

I don't know if there's information on the GPS sats in the public domain but logically they should have set up a production team of some kind

NASA did a lot of work on the benefits of design-for-repair on orbit during the 1970's IIRC there are a couple of conference proceedings on the matter, given it was expected the Shuttle was expected to launch 52 times a year and  eventually carry an upper stage.

Current high reliability design uses 3 parallel strings of components with cross straps between all units so you can get one working string from multiple failed parts by bypassing the signals onto another string. This is usually shown as a 2 string process but the 3 string will involve lots  more switches.

Running a single string system means 1/3 the mass (actually a bit less with none of those switches) or 3x the capability at the same mass.

Of course if you can schedule your replacements reliably you might just decide to replace them regardless of failure to ensure uninterrupted coverage.
"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.

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