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14.12.1972 
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Post 14.12.1972
Today it´s been 40 years since Apollo 17s LM Challenger fired up it´s main engine, and humanity left the moon and everything beyond the Van Allen radiation belt to probes and machines.

What´s left of it? The famous pic of our "Blue Marble" (shot on that very mission), of few pounds of lunar rock, and our desire for more.

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Fri Dec 14, 2012 4:15 am
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Post Re: 14.12.1972
40 years isn't enough of a milestone this century. Come back in a decade or so. :P

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Fri Dec 14, 2012 9:05 am
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Post Re: 14.12.1972
Unfortunately the leading nation in the space race... That's Be US, decided to shove it's head up it's own narcissistic back passage.

Unfortunately any penny that isn't paying for Goodies to win the politicians votes come election time, Is slated for "Practical" things.

On top of that NASA is failure averse, anything that isn't safe and planned out to the millionth degree is "too risky"

In the current atmosphere and culture of the space program the Apollo missions would have been nixed as too, expensive, complex, unsafe, untried, and too likely to fail.


Fri Dec 14, 2012 9:57 am
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Post Re: 14.12.1972
The era of "Apollo-like" projects is gone, I am afraid. Unless China decides to challenge the US openly in this area, there won't be another like this.

I am about 50% convinced that the first "settlement" on the Moon will be largely a commercial venture, most likely as part of a public-private partnership with one or more space agencies.


Fri Dec 14, 2012 10:00 am
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Post Re: 14.12.1972
Nah, full-private "moon safari". Unless the Chinese are actually serious about moving into space, but I think they'll have economic problems first.


Fri Dec 14, 2012 11:02 pm
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Post Re: 14.12.1972
Absalom wrote:
Nah, full-private "moon safari". Unless the Chinese are actually serious about moving into space, but I think they'll have economic problems first.


I doubt they're worse off economically than the Soviets were when they attempted to go for the Moon.

There is a space race going on in Asia. So far it has been mostly in terms of probes and satellites, but it is conceivable that China might at some point want to demonstrate its status of a rising power by sending people to the Moon, or even to Mars (much later). They have a lot of catching up to do, that's for sure, but if Apollo showed something, it's that you can land people there with 1960s-level technology.

I'd of course want us to go to the Moon for nobler/more practical reasons (to mine water at the poles and set up huge exoplanet-finding telescope arrays), but I can't exclude another "space race", this time with different actors.


Sat Dec 15, 2012 1:45 am
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Post Re: 14.12.1972
Kinda wish Britain had something in the way of a space program...Then again, giving the economic sh*t going on here, we'd probably have dropped any ways

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Sun Dec 16, 2012 4:11 pm
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Post Re: 14.12.1972
Michael wrote:
Kinda wish Britain had something in the way of a space program...Then again, giving the economic sh*t going on here, we'd probably have dropped any ways


Well Michael, as I'm sure Voctor_D can attest to, due his avatar being none other than the Reaction Engines "Skylon"

We are doing our bit too, for the advancement of Mankind to the stars!

http://www.reactionengines.co.uk/

http://www.bbc.co.uk/news/science-environment-20510112


Sun Dec 16, 2012 6:18 pm
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Post Re: 14.12.1972
UK has recently established a proper space agency, though of course the funding leaves a lot to be desired. Britain is also part of ESA, which is a bit closer to a proper space programme.

Skylon would be a glorious thing, a radical shift in how we go about orbital space travel. It would probably put most commercial expendable launch vehicles out of business very soon. I really hope it will eventually be built.


Mon Dec 17, 2012 2:52 am
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Post Re: 14.12.1972
SSO doesn´t work. Ask Tsiolkowsky.

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Mon Dec 17, 2012 9:52 am
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Post Re: 14.12.1972
Realistically now that the pre-cooler technology has been found to be successful, they believe Skylon could enter production as early a 2020.

Trantor wrote:
SSO doesn´t work. Ask Tsiolkowsky.


With that spirit, no one would ever achieve single stage to orbit.

And so far building bigger and bigger rockets has understandably failed to work. Skylon is a spaceplane, and she works. I've already cited the link to the successful pre-cooler testing last month which was the major technical barrier. Which only vindicates the ESA's position a year ago http://www.bis.gov.uk/ukspaceagency/news-and-events/2011/May/confidence-in-skylon. I knew the Chairman of Reaction Engines Ltd, and he told me that NASA unofficially supported it as well.

Victor_D wrote:
UK has recently established a proper space agency, though of course the funding leaves a lot to be desired. Britain is also part of ESA, which is a bit closer to a proper space programme.


That's correct, though our universities have always been involved for example the Huygens titan probe was a British project


Mon Dec 17, 2012 5:38 pm
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Post Re: 14.12.1972
Smithy wrote:
Realistically now that the pre-cooler technology has been found to be successful, they believe Skylon could enter production as early a 2020.
Trantor wrote:
SSO doesn´t work. Ask Tsiolkowsky.

With that spirit, no one would ever achieve single stage to orbit.

So? Who needs SSO?
Skylon is unflexible, complicated and expensive. It will never reach it´s proposed price, and there is no market to fill a 15 ton cargobay every two days.

Smithy wrote:
And so far building bigger and bigger rockets has understandably failed to work.

http://en.wikipedia.org/wiki/Saturn_V

Smithy wrote:
Skylon is a spaceplane, and she works.

Concorde "worked", too. And she was a formidable commercial failure.
Skylon will be the next commercial failure in a long row of british wrong decisions in aero/space, starting from the Brabazon Committee, the DH 106, the TSR and so on an so on.

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Tue Dec 18, 2012 4:20 am
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Post Re: 14.12.1972
Trantor wrote:
SSO doesn´t work. Ask Tsiolkowsky.


I can't, he's dead. Has been for 77 years, but by all means, he *surely* could have foreseen *all* advances in technology that would occur in the next 100 years...

Trantor wrote:
So? Who needs SSO?


SSTO is a must have if you want to have a future in space for humanity. Period.

Quote:
Skylon is unflexible, complicated and expensive. It will never reach it´s proposed price, and there is no market to fill a 15 ton cargobay every two days.


Says you, surely an acclaimed expert on Skylon and SSTO development...? :|

Skylon, if working as currently proposed, would be far more flexible than expendable launchers, less expensive in terms of the price of getting a kilogram to orbit than anything that's currently flying, and Skylon itself is a disruptive technology that would actually create the market it needs. I suggest that you read the economic analysis of Skylon REL has had done by an independent market analysis company. Even if basically everything went wrong in the market, Skylon would still be competitive.

Your comparison with Concorde is so off the mark that it's actually funny.


Tue Dec 18, 2012 5:07 am
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Post Re: 14.12.1972
trantor: if they manage to bring the cost/kg down by 25% or more there WILL be a market, you are aware there is a waiting list to get stuff up even at current prices?


Tue Dec 18, 2012 5:08 am
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Post Re: 14.12.1972
Victor_D wrote:
Trantor wrote:
SSO doesn´t work. Ask Tsiolkowsky.

I can't, he's dead. Has been for 77 years, but by all means, he *surely* could have foreseen *all* advances in technology that would occur in the next 100 years...

*sigh*
Ok, a bit more specific for you: http://en.wikipedia.org/wiki/Tsiolkovsk ... t_equation

SSTO is a dead end. A wrong answer to the question.


Victor_D wrote:
Trantor wrote:
So? Who needs SSO?

SSTO is a must have if you want to have a future in space for humanity. Period.

No, flexible systems is a "must-have" to react to the specific market demands.


Victor_D wrote:
Quote:
Skylon is unflexible, complicated and expensive. It will never reach it´s proposed price, and there is no market to fill a 15 ton cargobay every two days.

Says you, surely an acclaimed expert on Skylon and SSTO development...? :|

I am. Space, space flight, rockets, big projects (and their f*ck-ups...), how it REALLY works and everything related are a hobby of mine for more than three decades now.


Victor_D wrote:
Skylon, if working as currently proposed, would be far more flexible than expendable launchers, less expensive in terms of the price of getting a kilogram to orbit than anything that's currently flying, and Skylon itself is a disruptive technology that would actually create the market it needs. I suggest that you read the economic analysis of Skylon REL has had done by an independent market analysis company. Even if basically everything went wrong in the market, Skylon would still be competitive.

Your comparison with Concorde is so off the mark that it's actually funny.

You don´t really understand the "space market". There is no market to fill the bays of a skylon every two days, or even every month.

For starters, different satellites need different orbits. So you would need an additional stage for your freight, which increases costs and closes the gap to a standard rocket quickly. If there will be a gap at all, which i certainly doubt.

Second, an ideal freight into orbit uses all of the capacity. But there are no 15-ton sats for LEO.
But multiple sat launches again need additional stages, see #1.

Then, launching a satellite is often a national matter. Could you imagine the Japanese, the Russians or the Germans launch their gear with your bird?
Aside them, how many nations of this world have the money for spaceflight at all? The first 25 maybe, and the most important of them have their own business.

As long as there´s no commercial goal for starting massive amounts of LEO-sats, there is no point in creating bulk cargo capacity.


And last but not least Britain really has a long history of wrong decisions and failures in technology (No wonder there´s nothing left of the empire). This skylon will be no exeption. And in 15 years maybe there will be another TV-feature with Jeremy Clarkson about a british invention that didn´t made it.
;)


discord wrote:
trantor: if they manage to bring the cost/kg down by 25% or more there WILL be a market, you are aware there is a waiting list to get stuff up even at current prices?

The waiting lists are mainly because of the very specific business of space market/sat-transport, not for capacity-issues. See above.

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Last edited by Trantor on Tue Dec 18, 2012 6:13 am, edited 1 time in total.



Tue Dec 18, 2012 5:53 am
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Post Re: 14.12.1972
O ye, of little faith

Trantor wrote:
Concorde "worked", too. And she was a formidable commercial failure.


US Congress had banned Concorde landings in the US only letting her land at Washington DC, and no other airport. She was limited by closed thinking, and an inability to fly the most profitable air routes, so in a way she was doomed from the beginning by direct action of the US government being afraid of the "sonic booms" despite the fact concord didn't fly super sonic over land. Not only this she had an impeccable safety record. The famous crash was caused by a huge lump of metal which had fallen from a Continental Airlines DC-10 which was found to of been serviced incorrectly. The Air france flight 447 A330-200 plunged into the sea in 2009 due to it's pitot tubes freazing over and stalling. But still their are orders for about 100 of them.

She was years ahead of her time. Concord's flight path was over our house, and she was glorious.

Trantor wrote:
http://en.wikipedia.org/wiki/Saturn_V


Saturn V is a triple stage rocket, and not reusable, as well as being hugely expensive to build and launch, coming in at $1.17 billion in today's money.

Trantor wrote:
So? Who needs SSO?
Skylon is unflexible, complicated and expensive. It will never reach it´s proposed price, and there is no market to fill a 15 ton cargobay every two days.


It currently cost about $50 million and $400 million to put a satellite in orbit. Because a Skylon spaceplane can perform 200 flights, and has a projected unit cost of about £190 million. With no growth in the market the maths indicates that Skylon can put up to 15 tonne payloads (ie several satellites at once) for £5-6 million. Such as reduction in launch price, will undoubtedly increase the market size. Which could potentially push the price down considerably. Added also that satellites have a considerable wait time from manufacturing to launch due to the lengthy process of preparing a launch. Skylon would effectively undercut the entire market. But even with no market growth in the launch and service of satellites the economics of Skylon are sound.

Conventional rockets are also immensely expensive, complicated and inflexible. A reusable launch vehicle by it's definition is more flexible than a one launch rocket. Skylon is also human-rated giving the platform large potential benefits over it's more primitive rocket brethren. The technology to construct Skylon excluding the Pre-cooler heat exchangers has existed ever since Lockheed SR-71 Blackbird from 1966.

Trantor wrote:
Skylon will be the next commercial failure in a long row of british wrong decisions in aero/space, starting from the Brabazon Committee, the DH 106, the TSR and so on an so on.


DH 106 was a failure in it's first few years, but it's failure meant that no jet plane would ever be built with square windows. She was the first commercial jet liner ever, and thus the most pioneering and rival manufacturers meanwhile heeded the lessons learned from the Comet while developing their own aircraft. Even so she actually flew (with oval windows) successfully for over 30 years. Not exactly a failure. The Bristol Brabazon only ever wen't too prototype but was considered to large for her time. For the BAC TSR-2 bit off more than it could chew, I'll simply leave you with this quote.

"The trouble with the TSR-2 was that it tried to combine the most advanced state of every art in every field. The aircraft firms and the RAF were trying to get the Government on the hook and understated the cost. But TSR-2 cost far more than even their private estimates, and so I have no doubt about the decision to cancel."
Denis Healey, then Minister of Defence

The British aerospace industry has been at the forefront of design for last century, so it should come as no surprise that there were a large number of failures, but every failure expands our knowledge and expertise. "A smooth sea never made a skilled sailor". Let's just list some of the British aerospace achievements.

Development and production of the first aircraft with an enclosed cabin (the Avro Type F),
The first jet aircraft to enter service for the Allies in the Second World War (the Gloster Meteor)
The first commercial jet airliner to enter service (the de Havilland Comet)
The first aircraft capable of supercruise (the English Electric Lightning)
The first supersonic commercial jet airliner to enter service (the Aérospatiale-BAC Concorde)
The first fixed-wing V/STOL combat aircraft to enter service (the Hawker Siddeley Harrier)
The first twin-engined widebody commercial jet airliner (the Airbus A300)*
The largest commercial aircraft to enter service to date (the Airbus A380)*

* Airbus UK designs and manufactures the wings of all airbuses. Airbus wing design and production was assigned to UK largely because of the advanced wing design of Hawker Siddeley Trident

---

Currently space is prohibitively expensive, using arguable the mot inefficient way of putting anything into orbit. British Aerospace has always been on the cutting edge, and Skylon is no different to that tradition.


Tue Dec 18, 2012 6:07 am
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Post Re: 14.12.1972
Trantor wrote:
*sigh* Ok, a bit more specific for you: http://en.wikipedia.org/wiki/Tsiolkovsk ... t_equation


Oh great, this is the *first* time I hear about it :roll:

Quote:
SSTO is a dead end. A wrong answer to the question.


No, it's not. Pure rocket SSTO is perfectly possible with today's tech, it just has an awfully low payload fraction to be practical.

Skylon circumvents this problem by extracting atmospheric oxygen to reach the first 1/4 of the orbital velocity, saving mass for the spaceplane's dry mass plus significant payload.

Quote:
No, flexible systems is a "must-have" to react to the specific market demands.


And SSTO spaceplanes fit perfectly for that role, yes.

Victor_D wrote:
I am. Space, space flight, rockets, big projects (and their f*ck-ups...), how it REALLY works and everything related are a hobby of mine for more than three decades now.


Which of course qualifies you to make dismissive comments here, got it. I guess then all the other people who are *actually working* on this are deluded fools who don't understand the problem. Why don't you send them a letter and explain to them the depth of their folly? I am sure they'd appreciate it.

Quote:
You don´t really understand the "space market". There is no market to fill the bays of a skylon every two days, or even every month.


Yes, there is/will be once sufficiently cheap modes of transportation are introduced. Your argument is similar to those detracting the possibility of transoceanic passenger flights ("who would want to fly to America? Nobody would be able to afford it, and it would be dangerous and unpleasant. It's a non starter") in the early days of aviation. Nowadays they're something absolutely commonplace. It will be the same with space travel, just a bit more expensive due to the energy requirements.

Quote:
For starters, different satellites need different orbits. So you would need an additional stage for your freight, which increases costs and closes the gap to a standard rocket quickly. If there will be a gap at all, which i certainly doubt.


You don't know much about SKYLON, do you? This is actually addressed by the Skylon Upper Stage, a recoverable stage that can lift the satellite from Skylon's standard low-Earth orbit (LEO) to geostationary transfer orbit (GTO) and return back to the vehicle for recovery since their orbits remain synced (I think they propose 7:1 resonance, don't remember exactly).

As for different inclinations in LEO, they're no problem for a Skylon, which can be launched in any inclination. A Skylon taking off from spaceport near the equator (such as the CSG in French Guyana) can launch a satellite to any orbit.

Quote:
Second, an ideal freight into orbit uses all of the capacity. But there are no 15-ton sats for LEO.
Multiple sat launches again need additional stages, see #1.


See above. Due to the low price, it would still be profitable to launch even if the payload capacity wasn't fully used.

Quote:
Then, launching a satellite is often a national matter. Could you imagine the Japanese, the Russians or the Germans launch their gear with your bird?


So, your market-based argument against Skylon has nothing to do with... markets? Thanks for clarification. Skylon is meant to be a commercial product. Other nations can buy them if they want, just as they buy Airbuses/Boeings without each developing their own airliners. The business model for Skylon is to build them for others who then operate them as they see fit for whatever purpose they wish.

Skylon would actually probably drive all low/medium-lift expendable launchers out of business (especially with little subsidy-dumping in the beginning). There would still remain a niche market for the heavy-lift vehicles (something on the order of SpaceX's Falcon Heavy and higher).

Quote:
Aside them, how many nations of this world have the money for spaceflight at all? The first 25 maybe, and the most important of them have their own business.


Government-exclusive space is history, get used to it.

Quote:
As long as there´s no commercial goal for starting massive amounts of LEO-sats, there is no point in creating bulk cargo capacity.


The demand for space is growing. It will explode once lower launch costs (Skylon and cheaper expendable launchers) make it affordable for a wide range of other commercial and public customers.

Quote:
And last but not least Britain really has a long history of wrong decisions and failures in technology (No wonder there´s nothing left of the empire). This skylon will be no exeption. And in 15 years maybe there will be another TV-feature with Jeremy Clarkson about a british invention that didn´t made it.
;)


You have to lend me your crystal ball, I think you're not using it correctly ;)


Tue Dec 18, 2012 6:36 am
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Post Re: 14.12.1972
Smithy wrote:
O ye, of little faith

Yes. Because i recognize a dreamer when i see one. That´s not meant ad hominem.


Smithy wrote:
Trantor wrote:
Concorde "worked", too. And she was a formidable commercial failure.

US Congress had banned Concorde landings in the US only letting her land at Washington DC, and no other airport. She was limited by closed thinking, and an inability to fly the most profitable air routes, so in a way she was doomed from the beginning by direct action of the US government being afraid of the "sonic booms" despite the fact concord didn't fly super sonic over land.

C´mon, every Concorde-flight on approach to the US east cost was low on fuel, that´s why she always got a priority-landing. There is simply no "overland" after reaching the US and therefor no "profitable routes".


Smithy wrote:
Not only this she had an impeccable safety record. The famous crash was caused by a huge lump of metal which had fallen from a Continental Airlines DC-10 which was found to of been serviced incorrectly.

No, do yourself a favour and the the BEA-report attentively. The small part of that DC-10 was only one part in the chain of errors. The F´up was bad maintenance (forgotten spacer that made the bird veer to side where the lost wear strip of the DC-10 was), bad organisation (plane was overloaded, COG was exceeded, etc) and bad airmanship (the flight engineer, who was illegally on board due to his expired medical, shut down the wrong engines).

If all, it was all Air France´s fault. Laissez Faire and technology are always on collison course.


Smithy wrote:
The Air france flight 447 A330-200 plunged into the sea in 2009 due to it's pitot tubes freazing over and stalling.

Again Air France´s fault, and again bad airmanship.


Smithy wrote:
Conventional rockets are also immensely expensive, complicated and inflexible.

They´re several magnitudes less complex.


Smithy wrote:
A reusable launch vehicle by it's definition is more flexible than a one launch rocket.

For Joe Average maybe. Not for those who UNDERSTAND the space market.


Smithy wrote:
Skylon is also human-rated

Which is unnecessary, and adds magnitudes more cost and complexity.


Smithy wrote:
The first jet aircraft to enter service for the Allies in the Second World War (the Gloster Meteor)

A lame duck with the wrong tech from the start. Radial engines only serve well in turbo-props.
The Germans were right from the start with their axial-turbos.


Smithy wrote:
The first commercial jet airliner to enter service (the de Havilland Comet)

..which killed over 100 people.


Smithy wrote:
The first aircraft capable of supercruise (the English Electric Lightning)

Not bad for it´s time. But still outdated quickly.


Smithy wrote:
The first supersonic commercial jet airliner to enter service (the Aérospatiale-BAC Concorde)

A huge commercial success... 8-)


Smithy wrote:
The first fixed-wing V/STOL combat aircraft to enter service (the Hawker Siddeley Harrier)

Indeed an interesting aircraft.


Smithy wrote:
The first twin-engined widebody commercial jet airliner (the Airbus A300)*
The largest commercial aircraft to enter service to date (the Airbus A380)*

C´mon. To pretend they´re british is as odd as saying they were german. :roll:
(And btw, i was part of the 380 rescue)


Smithy wrote:
British Aerospace has always been on the cutting edge, and Skylon is no different to that tradition.

Yes, which means that it´ll be a commercial failure very sure. scnr.

True, british inventors were great, but where is britain now? You invented the locomotive, and today? For the 60163 Tornado you had to buy the boiler from, well, us Germans. Gosh. http://en.wikipedia.org/wiki/A1_Steam_Locomotive_Trust

Or cars. Where is the british industry today? Last time i checked, Rolls-Royce is owned by BMW. And Bentley by VW. The Mini - no successor. The new Mini? A BMW. A Golf-competition from Britain? Nope.

Computers. Colossus. A remarkable thing. Winning the war for you, saving 100000 british souls at least. Denied, forgotten, it´s inventors driven into poverty (Flowers) and suicide (Turing).

Really, you Brits have an extraordinary streak to f*** up tech. A truly sad image for an anglophile like me.




Edit: Haha, i just read the wikipediaarticle about the Loco again, and obviously some chauvinist removed the fact that the boiler is "Made in Germany". How pathetic is that?

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Last edited by Trantor on Tue Dec 18, 2012 7:54 am, edited 1 time in total.



Tue Dec 18, 2012 7:08 am
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Post Re: 14.12.1972
Victor_D wrote:
Trantor wrote:
*sigh* Ok, a bit more specific for you: http://en.wikipedia.org/wiki/Tsiolkovsk ... t_equation


Oh great, this is the *first* time I hear about it :roll:

It is a difference to just look on it, or to really understand the implications.


Victor_D wrote:
Quote:
SSTO is a dead end. A wrong answer to the question.

No, it's not. Pure rocket SSTO is perfectly possible with today's tech, it just has an awfully low payload fraction to be practical.

Which is why nobody uses SSTO at all.


Victor_D wrote:
Skylon circumvents this problem by extracting atmospheric oxygen to reach the first 1/4 of the orbital velocity, saving mass for the spaceplane's dry mass plus significant payload.

That remains to be seen. I say it won´t work.


Quote:
Quote:
No, flexible systems is a "must-have" to react to the specific market demands.

And SSTO spaceplanes fit perfectly for that role, yes

Nope.


Victor_D wrote:
Quote:
I am. Space, space flight, rockets, big projects (and their f*ck-ups...), how it REALLY works and everything related are a hobby of mine for more than three decades now.

Which of course qualifies you to make dismissive comments here, got it.

I also sport an engineers degree. ;)


Victor_D wrote:
I guess then all the other people who are *actually working* on this are deluded fools who don't understand the problem.

Either that, or they cash in tax money from deluded fools.


Victor_D wrote:
Why don't you send them a letter and explain to them the depth of their folly? I am sure they'd appreciate it.

And i´m sure they won´t. I´m experienced, i was sued for action like that before the cargolifter debacle surfaced by f*ckface von Gablenz himself.
No, i usually don´t repeat mistakes, i´d rather lean back and enjoy the show. ;)


Victor_D wrote:
Quote:
You don´t really understand the "space market". There is no market to fill the bays of a skylon every two days, or even every month.

Yes, there is/will be once sufficiently cheap modes of transportation are introduced.

Uh-hu. Tell me about them.


Victor_D wrote:
Your argument is similar to those detracting the possibility of transoceanic passenger flights ("who would want to fly to America? Nobody would be able to afford it, and it would be dangerous and unpleasant. It's a non starter") in the early days of aviation.

No, the "early days of aviation" were before WW2. After WW2 and the huge progress in tech it was plain to see for everyone that aviation over the pond IS the next big thing.
No point for you, sry.


Victor_D wrote:
Nowadays they're something absolutely commonplace. It will be the same with space travel, just a bit more expensive due to the energy requirements.

A "bit". Let´s rather say some magnitudes.


Victor_D wrote:
Quote:
For starters, different satellites need different orbits. So you would need an additional stage for your freight, which increases costs and closes the gap to a standard rocket quickly. If there will be a gap at all, which i certainly doubt.

You don't know much about SKYLON, do you? This is actually addressed by the Skylon Upper Stage, a recoverable stage that can lift the satellite from Skylon's standard low-Earth orbit (LEO) to geostationary transfer orbit (GTO) and return back to the vehicle for recovery since their orbits remain synced (I think they propose 7:1 resonance, don't remember exactly).

And with that magic carpet there´s still 15 tons payload? 8-)


Victor_D wrote:
As for different inclinations in LEO, they're no problem for a Skylon, which can be launched in any inclination. A Skylon taking off from spaceport near the equator (such as the CSG in French Guyana) can launch a satellite to any orbit.

No, equatorial bases are only good for GTO, or equatorial LEO.


Victor_D wrote:
So, your market-based argument against Skylon has nothing to do with... markets?

No, read again.


Victor_D wrote:
Thanks for clarification.

No need to get b*tchy. ;)


Victor_D wrote:
Skylon would actually probably drive all low/medium-lift expendable launchers out of business (especially with little subsidy-dumping in the beginning). There would still remain a niche market for the heavy-lift vehicles (something on the order of SpaceX's Falcon Heavy and higher).

Dream on. ;)


Victor_D wrote:
Quote:
Aside them, how many nations of this world have the money for spaceflight at all? The first 25 maybe, and the most important of them have their own business.

Government-exclusive space is history, get used to it.

Sure. 8-)


Victor_D wrote:
Quote:
As long as there´s no commercial goal for starting massive amounts of LEO-sats, there is no point in creating bulk cargo capacity.

The demand for space is growing. It will explode once lower launch costs (Skylon and cheaper expendable launchers) make it affordable for a wide range of other commercial and public customers.

There is no application for that magnitude of capacity.


Victor_D wrote:
Quote:
And last but not least Britain really has a long history of wrong decisions and failures in technology (No wonder there´s nothing left of the empire). This skylon will be no exeption. And in 15 years maybe there will be another TV-feature with Jeremy Clarkson about a british invention that didn´t made it.
;)

You have to lend me your crystal ball, I think you're not using it correctly ;)

No crystal. Just an extrapolation. 8-)

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Tue Dec 18, 2012 7:34 am
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Post Re: 14.12.1972
Trantor wrote:
For starters, different satellites need different orbits. So you would need an additional stage for your freight, which increases costs and closes the gap to a standard rocket quickly. If there will be a gap at all, which i certainly doubt.

Second, an ideal freight into orbit uses all of the capacity. But there are no 15-ton sats for LEO.
But multiple sat launches again need additional stages, see #1.


Reaching LEO is still the biggest hurdle (either technical or financial). And the free tonnage could be used for a booster to bring a payload up to the required orbit.

Trantor wrote:
Then, launching a satellite is often a national matter. Could you imagine the Japanese, the Russians or the Germans launch their gear with your bird?
Aside them, how many nations of this world have the money for spaceflight at all? The first 25 maybe, and the most important of them have their own business.


There's plenty of payload crossovers already in classic rocket launches.

Trantor wrote:
As long as there´s no commercial goal for starting massive amounts of LEO-sats, there is no point in creating bulk cargo capacity.


Dunno, but such a plane could be used as a cheaper and more "on the spot" vehicle to bring up spares and technicians to fix stuff in orbit (the Hubble maintenance flights come to mind).

Trantor wrote:
And last but not least Britain really has a long history of wrong decisions and failures in technology (No wonder there´s nothing left of the empire). This skylon will be no exeption. And in 15 years maybe there will be another TV-feature with Jeremy Clarkson about a british invention that didn´t made it.
;)


Well, there's two British-invented technologies I could mention that made another country powerful beyond means: the steam catapult, and the canted flight deck...

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Tue Dec 18, 2012 9:36 am
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Post Re: 14.12.1972
trantor: so basically, unless someone changes the variables outside of the equation made by this russkie SSTO can't be profitable....check.

so, the idea with the skylon is
#1 improve mass ratio by importing air for a significant part of the trip....how much of the mass on a ordinary rocket is oxygen again?
#2 improve thrust efficiency, one part interestingly enough by the pre-cooler, instead of running it from the exhaust(turbo charger style) it uses waste heat, brilliant really...assuming it works of course.
#3 theoretically you could use wings and fly upwards using wing lift and accelerate that way, exceedingly inefficient for pure rocket engines, not so much for jet engines.

and even if it fails as a space transport, it could probably work just fine for extreme height transport around the globe, the 'orbital shuttle 30 minutes from new york to tokyo' of science fiction, being 50km up does not increase the planetary radius much, but it does reduce air friction immensely, given less than a fifth the air pressure much higher velocity would be attainable.

current commercial flight, new york to tokyo takes about 12 hours, kick that up to mach 5 at higher altitude and mostly ballistic, should be possible to do it in 2 hours.

question, how much would it help a 15 ton rocket to start at 50km, bypassing most of the atmosphere, is atmosphere a problem for rocket engines? i have some recollection of different designs being variably efficient at different air pressure.

finally, combine something with huge maglev launcher http://en.wikipedia.org/wiki/StarTram sounds feasible, costly but feasible.


Tue Dec 18, 2012 3:24 pm
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Post Re: 14.12.1972
GeoModder wrote:
Reaching LEO is still the biggest hurdle (either technical or financial). And the free tonnage could be used for a booster to bring a payload up to the required orbit.

This is not just a booster, it is an entire upper stage, adding complexity and - cost.


GeoModder wrote:
There's plenty of payload crossovers already in classic rocket launches.

I just had a good chuckle on the thought that maybe North Korea or Iran would knock on the door...


GeoModder wrote:
Dunno, but such a plane could be used as a cheaper and more "on the spot" vehicle to bring up spares and technicians to fix stuff in orbit (the Hubble maintenance flights come to mind).

The price for a launch is always the same. Without a fully load the price per Kg rises.


GeoModder wrote:
Well, there's two British-invented technologies I could mention that made another country powerful beyond means: the steam catapult, and the canted flight deck...

...which would be worthless without an invention from Germany: The axial-turbo jet-engine. 8-)


discord wrote:
#1 improve mass ratio by importing air for a significant part of the trip....how much of the mass on a ordinary rocket is oxygen again?

They save only a quarter of the oxygen. But they add wings, undercarriage and magnitudes of complexity. It doesn´t count up.


discord wrote:
#2 improve thrust efficiency, one part interestingly enough by the pre-cooler, instead of running it from the exhaust(turbo charger style) it uses waste heat, brilliant really...assuming it works of course.

Well, no such thing. Theoretical max of the oxygen/hydrogen-reaction is around 5200 m/s². In practice it´ll be more like 4600, and Space Shuttle´s SSME were pretty much there with IIRC 4460.


discord wrote:
#3 theoretically you could use wings and fly upwards using wing lift and accelerate that way, exceedingly inefficient for pure rocket engines, not so much for jet engines.

With rocket power there´s no need for wings.


discord wrote:
and even if it fails as a space transport, it could probably work just fine for extreme height transport around the globe, the 'orbital shuttle 30 minutes from new york to tokyo' of science fiction, being 50km up does not increase the planetary radius much, but it does reduce air friction immensely, given less than a fifth the air pressure much higher velocity would be attainable.

current commercial flight, new york to tokyo takes about 12 hours, kick that up to mach 5 at higher altitude and mostly ballistic, should be possible to do it in 2 hours.

At which price? Today we don´t even have supersonic passengerflight anymore.


discord wrote:
question, how much would it help a 15 ton rocket to start at 50km, bypassing most of the atmosphere, is atmosphere a problem for rocket engines?

Well, the problem is separating the stages. "Just open a hatch" at Mach 5 and kick out a rocket? Not possible. The calculations and windtunneltests for Project Saenger showed that.
And for rocketengines, yes they have different amount of net thrust on groundlevel vs spacevoid, but this difference is not crucial, since it only affects stage 1, where you usually help yourself with dedicated engines and boosters. Upper stages then are specialized on working in the void.

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Tue Dec 18, 2012 4:44 pm
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Post Re: 14.12.1972
Trantor wrote:
So? Who needs SSO?
Skylon is unflexible, complicated and expensive. It will never reach it´s proposed price, and there is no market to fill a 15 ton cargobay every two days.
Too early to say. There wasn't a market for tons of aluminum, but when a good-enough process to refine it came along, a market came into existence. This is also the reason why Microsoft's NT series succeeded while OS/2 failed (though in that case, Microsoft specifically created the market itself, and IBM failed to realize that it needed to).

In short, it's too early to say that Skylon will fail. Even if it does fail, I expect a plan to shortly afterwards materialize to use it's engines for a winged first-stage (even SpaceShipOne got into vacuum, and once you get there, you can kick the second stage out however you want).

Trantor wrote:
Victor_D wrote:
Quote:
You don´t really understand the "space market". There is no market to fill the bays of a skylon every two days, or even every month.

Yes, there is/will be once sufficiently cheap modes of transportation are introduced.

Uh-hu. Tell me about them.
Who knows, they might get business from Bigelow. Space hotels need their amenities after all, and a convertable cargo-or-passengers vehicle would indeed by flexible in that role. We'll see.

Trantor wrote:
Victor_D wrote:
Quote:
As long as there´s no commercial goal for starting massive amounts of LEO-sats, there is no point in creating bulk cargo capacity.

The demand for space is growing. It will explode once lower launch costs (Skylon and cheaper expendable launchers) make it affordable for a wide range of other commercial and public customers.

There is no application for that magnitude of capacity.
YET. It's too early to see if Skylon (or even something else) will create one or not, but we should know within the next decade.

Trantor wrote:
Victor_D wrote:
Quote:
And last but not least Britain really has a long history of wrong decisions and failures in technology (No wonder there´s nothing left of the empire). This skylon will be no exeption. And in 15 years maybe there will be another TV-feature with Jeremy Clarkson about a british invention that didn´t made it.
;)

You have to lend me your crystal ball, I think you're not using it correctly ;)

No crystal. Just an extrapolation. 8-)
Only accurate if the "game" doesn't change. Lower prices, and you'll always see more business, the only question is if it'll happen in enough quantity and fast enough.

Assuming that Skylon is actually cheaper. How much of launch costs was spent on the launcher itself? I half-recall reading somewhere that it was a bigger portion than the fuel. Imagine air travel if every vehicle was one-flight only.

Trantor wrote:
GeoModder wrote:
Reaching LEO is still the biggest hurdle (either technical or financial). And the free tonnage could be used for a booster to bring a payload up to the required orbit.

This is not just a booster, it is an entire upper stage, adding complexity and - cost.
And the difference is what? Both need engines, electronics, and fuel. Once you reach vacuum, the only thing you need to worry about is whether you have sufficient thrust & impulse to insert yourself into your desired orbit. I honestly can't think of anything that one would require but the other wouldn't.

Trantor wrote:
discord wrote:
#1 improve mass ratio by importing air for a significant part of the trip....how much of the mass on a ordinary rocket is oxygen again?

They save only a quarter of the oxygen. But they add wings, undercarriage and magnitudes of complexity. It doesn't count up.
For any reusable craft, if the maintenance costs are low enough, it'll be worth it. Given that Skylon has aimed to be a light craft for it's domain, instead of a heavy craft like the Space Shuttle, they might be able to make it work with whatever lightening of payload they wind up requiring. From illustrations, it looks like most of the internal volume will be fuel & oxidizer, restricting the question to whether they can charge enough per kg for whatever the average load is.

Trantor wrote:
discord wrote:
#2 improve thrust efficiency, one part interestingly enough by the pre-cooler, instead of running it from the exhaust(turbo charger style) it uses waste heat, brilliant really...assuming it works of course.

Well, no such thing. Theoretical max of the oxygen/hydrogen-reaction is around 5200 m/s². In practice it´ll be more like 4600, and Space Shuttle´s SSME were pretty much there with IIRC 4460.
The Space Shuttles themselves are an overweight victim of feature-creep, and therefor not a good reference.

Trantor wrote:
discord wrote:
#3 theoretically you could use wings and fly upwards using wing lift and accelerate that way, exceedingly inefficient for pure rocket engines, not so much for jet engines.

With rocket power there´s no need for wings.
That SSTO field is Carmack's ;) .

Trantor wrote:
discord wrote:
and even if it fails as a space transport, it could probably work just fine for extreme height transport around the globe, the 'orbital shuttle 30 minutes from new york to tokyo' of science fiction, being 50km up does not increase the planetary radius much, but it does reduce air friction immensely, given less than a fifth the air pressure much higher velocity would be attainable.

current commercial flight, new york to tokyo takes about 12 hours, kick that up to mach 5 at higher altitude and mostly ballistic, should be possible to do it in 2 hours.

At which price? Today we don´t even have supersonic passengerflight anymore.
We don't have space hotels at all, but there's sufficient market that a business is moving forward. If you want to use pricing as a counter, then go out and start surveying multimillionaires, the primary market would coalesce around the one created to cater to them.

Trantor wrote:
discord wrote:
question, how much would it help a 15 ton rocket to start at 50km, bypassing most of the atmosphere, is atmosphere a problem for rocket engines?

Well, the problem is separating the stages. "Just open a hatch" at Mach 5 and kick out a rocket? Not possible. The calculations and windtunneltests for Project Saenger showed that.
And for rocketengines, yes they have different amount of net thrust on groundlevel vs spacevoid, but this difference is not crucial, since it only affects stage 1, where you usually help yourself with dedicated engines and boosters. Upper stages then are specialized on working in the void.
The big difference is that in sufficient vacuum you can "just open a hatch". This is precisely (well, okay, there were also springs involved) how the space shuttles deployed every satellite that they ever launched. A zero-gee vacuum works wonders for simplifying aerodynamic concerns, which in turn makes stag separation much simpler than it otherwise is. Just remember to shut off the engines a second or three before you begin deployment.

I suspect that you didn't place enough thought into this rebuttal.


Wed Dec 19, 2012 5:06 am
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Post Re: 14.12.1972
Trantor wrote:
...which would be worthless without an invention from Germany: The axial-turbo jet-engine.


Which wouldn't of been possible without Brit Air Cdre Sir Frank Whittle inventing the Turbojet Engine, (though I will almost certainly give secondary credit to Hans von Ohain).
But axial compressors were first postulated Frenchman Maxime Guillaume, and all the technical work to actually make them technically viable was done by Alan Arnold Griffith an Englishman in 1926.

Trantor wrote:
I also sport an engineers degree


I'm half way through my Mech Eng degree, though I'll admit the only design experience I have had so far is with high-cycle fatigue shaft designs, knock-out drums for oil refineries, single plate clutches, water propellers, agricultural equipment (mainly plasticulture) and niche compact air seeding devices.

So, what is a flexible launch platform? I was assuming a platform that can launch a range of separate masses into multiple orbit types (let alone being reusable). Instead of simply stating what you think isn't, please explain what is? I'm assuming you define flexibility to the launch frame being set up exactly for the load in question, mainly because the load in question is the only thing it will ever launch.

Anyhow, how does re-usability not drive cost down? A large amount of cost is simply that rockets are one hit wonders. And I would have to disagree with the whole commercial satellites not being a viable industry thing.

Trantor wrote:
That remains to be seen. I say it won´t work.


Clearly the ESA disagrees. As it's kinda the crux of the whole design to be air breathing.

---
Enough of this vile pessimism! ;) (Don't you dare pretend it's "realism" urgh!)

Well let's just see in 2020 where auld skylon is, when they might of built her or not.

Trantor wrote:
C´mon, every Concorde-flight on approach to the US east cost was low on fuel, that´s why she always got a priority-landing. There is simply no "overland" after reaching the US and therefor no "profitable routes".


Concorde had a range of 7,250 km, London-New York is 5570.2m, London-DC is 5905.08. Why fill her up to maximum, when you can only go to one place. Maybe if America wasn't such a closed shop maybe they would of upgraded Concorde to the B-Type


Wed Dec 19, 2012 6:16 am
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Post Re: 14.12.1972
Absalom wrote:
Trantor wrote:
discord wrote:
#2 improve thrust efficiency, one part interestingly enough by the pre-cooler, instead of running it from the exhaust(turbo charger style) it uses waste heat, brilliant really...assuming it works of course.

Well, no such thing. Theoretical max of the oxygen/hydrogen-reaction is around 5200 m/s². In practice it´ll be more like 4600, and Space Shuttle´s SSME were pretty much there with IIRC 4460.

The Space Shuttles themselves are an overweight victim of feature-creep, and therefor not a good reference.

Please read again: The theoretical MAX IS 5200. The MAX. It´s not important where the SSME´s were attached to. They are the reference, and there is only a few percent left in practice.
And since that Skylonthingy is neither flesh nor fish it will not be better in terms of efficiency. Because for that goal it should specialize on the "rocket-mode" even more.


Absalom wrote:
The big difference is that in sufficient vacuum you can "just open a hatch". This is precisely (well, okay, there were also springs involved)

We were talking about 50 miles height. Still too much atmosphere there.


Absalom wrote:
Quote:
This is not just a booster, it is an entire upper stage, adding complexity and - cost.

And the difference is what?

A booster can be a cheap solid-state type without any electronics.
This can´t be used as a stage.


Absalom wrote:
I suspect that you didn't place enough thought into this rebuttal.

LOL. ;)


Smithy wrote:
Trantor wrote:
...which would be worthless without an invention from Germany: The axial-turbo jet-engine.

Which wouldn't of been possible without Brit Air Cdre Sir Frank Whittle inventing the Turbojet Engine, (though I will almost certainly give secondary credit to Hans von Ohain).

No, no, and no. Radialengines like that from Whittle are totally different to axial-turbos. Too clumsy and inefficient, since there´s a limit to their gas velocity and too much inner surface. Even the basic design with it´s gazillion of discrete chambers is not used anymore, while the basic design of the germans was virtually all the same until the invention of fans, and even then the hot core stayed the same.


Smithy wrote:
But axial compressors were first postulated Frenchman Maxime Guillaume, and all the technical work to actually make them technically viable was done by Alan Arnold Griffith an Englishman in 1926.

There were a lot of people who wrote or published some papers.
But where´s their hardware?


Smithy wrote:
So, what is a flexible launch platform? I was assuming a platform that can launch a range of separate masses into multiple orbit types (let alone being reusable). Instead of simply stating what you think isn't, please explain what is?

Yes, two stages with boosters for any earthorbit, three stages plus boosters for anything beyond.
Fuel methane and LOX, since they sport the same physiochemical properties and have a good thrust. So no need for different types of pumps, valves etc.
Boosters vary in numbers, and to a degree in size. But they sport the same tech as the stages, so no throw-away solid boosters.
Main-engines of stage 1 and boosters are to be recovered (landing in the water with parachute and airbags) and reused, with an expected live of 12 starts. Not more, because that would add complexity and cost.
Upper stage either the same as stage 1, or hydrogen/LOX (like the Vulcain) for advanced orbits or heavy satellites.
Cost reduction through standardization of parts, tanks, engines, electronics, and even the most parts of the satellites like backbone and electrics.


Smithy wrote:
Enough of this vile pessimism! ;) (Don't you dare pretend it's "realism" urgh!)

It is.


Smithy wrote:
Well let's just see in 2020 where auld skylon is, when they might of built her or not.

Yes. The internet doesn´t forget. I look forward to Jeremy Clarksons report on that failure. I love his Sheffield-accent. 8-)


Smithy wrote:
Maybe if America wasn't such a closed shop maybe they would of upgraded Concorde to the B-Type

Oh, those americans, those n****** f***$%§* s**** ** b***&?**.
Uh, wait one. It wasn´t them, it was the whole misconception of SST for the masses. And fuel prices. And a gazillion things more. Hups.

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Wed Dec 19, 2012 8:28 am
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