The Reaction Engines Skylon/SABRE Master Thread (6)

[Coastal Ron]

Both Skylon and Falcon 9 (would) do a lot more than 'supplying ISS'. The 'supplying ISS' part is done by Dragon...

Yes, Falcon 9 can carry human-capable spacecraft.  I'm not that up to date on the intended uses for the Skylon, but would it be able to carry human-capable spacecraft?

...but NASA paid for "some development funding plus the purchase of several demonstration flights" for Falcon 9.

Just in case everyone is not familiar with what the NASA COTS program paid for, and what it didn't, the COTS program only paid SpaceX $5M for a Falcon 9 launch - which at that time was worth about 10X more for a commercial launch contract.

So no, NASA was not really paying for a full Falcon 9, but just reimbursing SpaceX for far less than the full value of the demonstration flight.  Also they paid SpaceX $5M for what they call "Demo Readiness Review".

Had they instead limited the funding to capsules launchable from existing rockets

I strongly encourage people to research what the COTS program does and does not pay for before jumping to conclusions, since that would save a lot of electrons...

No, NASA did not pay SpaceX to develop the Falcon 9.  The COTS program was only for spacecraft related development, which of course included testing on a rocket.

The real goal here is cheaper access to space, and the ability to buy rides domestic rather than Russian or European. You know, the other countries able (before ATV's retirement) to send craft to the ISS.

I disagree.  The COTS/CRS program was to develop redundancy for the ISS resupply transportation system, not to specifically lower the price to access "space".

Elon Musk's goal is to lower the cost to access space, which is why he was funding the development of the Falcon 9 before the NASA COTS and CRS contract wins.

So the 'need' for the UK to fund it's own space launch system would be the ability to 'buy local', whether or not it participates in ISS. Just like the USA wants to buy domestic for access to space in general, including supplying ISS.

I don't know what the UK's goal is, but from what supporters say, it's ultimate use is commercial.

But to make it comparable to what NASA did for SpaceX, they would also have to pay for "some development funding plus the purchase of several demonstration flights" of the SABRE flight frame, and the eventual Skylon itself.

To make it comparable to the competitive contracts SpaceX won for NASA's CRS program, the UK government would have to have a need to move mass to space for a period of time, for a defined need.  Not sure they have that need, and if they don't then the UK government is funding the Skylon program because they want their industry to pursue cutting edge technologies that MIGHT have profitable uses for UK industry - which is fine.  But that is not what NASA did with the CRS program.

[flymetothemoon]

Yes, Falcon 9 can carry human-capable spacecraft.  I'm not that up to date on the intended uses for the Skylon, but would it be able to carry human-capable spacecraft?

Yes. Skylon is intended and designed from the beginning to carry humans and for "aircraft-like" operations. You don't seem to know much about it! 

[lkm]

The Reinventing Space conference was last month and there are videos up on facebook.
The Access to Space  video is relevant to this thread, those unclear on U.K. national space policy might like to watch the first presentation from Bradspace while the second is from Orbital Access about their Plans.



https://www.facebook.com/rispace.conference/videos/vb.1422989437939886/1799807703591389/?type=2&theater

[john smith 19]

Yes. Skylon is intended and designed from the beginning to carry humans and for "aircraft-like" operations.

That's not quite fair.

IIRC it was Hempsell (not sure if on one of these threads or during a Space Show guest appearance) who said REL were looking to find a partner who wanted to develop a human carrying module for Skylon during the development test flights.

However they were looking to rack up enough flight hours (without mishap) that the module would be viewed as safe by default, but I can't recall the number of flying hours needed.

[john smith 19]

The Reinventing Space conference was last month and there are videos up on facebook.
https://www.facebook.com/rispace.conference/videos/vb.1422989437939886/1799807703591389/?type=2&theater

Finally got a chance to view the Orbital Access presentation.

If I understood it right this is a reusable small sat launcher 450Kg to 650Km orbit at 88deg inclination. It seems to be TSTO sot he payload bay has to be big enough for both the payload and a 2nd stage. The PYLB look more flattened than circular.

Unclear if the 2nd stage/payload package forms the top of the PLB or it has separate doors. Forming the top lets more mass go to the 2nd stage but leaves a big hole in the upper fuselage during the deceleration.

Things get vaguer when you come to its involvement in SABRE testing. The PLB is described as housing LH2 tanks for this. No mention of the LOX tanks. So he seems to be saying it's for air breathing testing of SABRE in the M0.9 to supersonic range.

Where such an engine would get it's air from is also unclear. 

The presentation raises more questions than it answers. I'm not really clear what REL gains. All I can see OA getting is the ability to charge REL for this work. The fact the LV should be flight proven by this time and hence less risky seems a minimal benefit given the environment SABRE will be in is nothing like it's environment on SABRE, the D21 like test vehicle or (AFAIK) any TSTO launch proposals incorporating it.

Not really a good presentation at making the case for using it really.

[lkm]

The Reinventing Space conference was last month and there are videos up on facebook.
https://www.facebook.com/rispace.conference/videos/vb.1422989437939886/1799807703591389/?type=2&theater

Finally got a chance to view the Orbital Access presentation.

If I understood it right this is a reusable small sat launcher 450Kg to 650Km orbit at 88deg inclination. It seems to be TSTO sot he payload bay has to be big enough for both the payload and a 2nd stage. The PYLB look more flattened than circular.

Unclear if the 2nd stage/payload package forms the top of the PLB or it has separate doors. Forming the top lets more mass go to the 2nd stage but leaves a big hole in the upper fuselage during the deceleration.

Things get vaguer when you come to its involvement in SABRE testing. The PLB is described as housing LH2 tanks for this. No mention of the LOX tanks. So he seems to be saying it's for air breathing testing of SABRE in the M0.9 to supersonic range.

Where such an engine would get it's air from is also unclear. 

The presentation raises more questions than it answers. I'm not really clear what REL gains. All I can see OA getting is the ability to charge REL for this work. The fact the LV should be flight proven by this time and hence less risky seems a minimal benefit given the environment SABRE will be in is nothing like it's environment on SABRE, the D21 like test vehicle or (AFAIK) any TSTO launch proposals incorporating it.

Not really a good presentation at making the case for using it really.

That was my impression too. I can only imagine that OA is trying to position itself to be a Skylon launch provider and this is their game plan to amass sufficient operational experience with htol launch and SABRE to do that by the time Skylon's become available.

[Coastal Ron]

Yes, Falcon 9 can carry human-capable spacecraft.  I'm not that up to date on the intended uses for the Skylon, but would it be able to carry human-capable spacecraft?

Yes. Skylon is intended and designed from the beginning to carry humans and for "aircraft-like" operations.

That video does show "aircraft-like" operations (i.e. like airliners, passengers have no escape system in flight), but it did not answer my question, which was whether Sklyon could carry human-capable spacecraft.  What was shown in the video was a module being carried as cargo, not a spacecraft being carried as cargo - there is a difference.

But the cargo area looks like it could carry a good sized spacecraft, assuming there are no limitations other than size.

I will say though that the Skylon, assuming the ISS is still in operation, will never dock with the ISS.  As I recall the Shuttle caused too much stress on the ISS "frame" during all the times it docked with the ISS, and the Skylon would have a much larger bending moment to be concerned about.  But if the Skylon carried a passenger-carrying spacecraft to orbit, that spacecraft would be able to dock with the ISS with no issue.

You don't seem to know much about it! 

Didn't I state that in my question??

[lkm]

Yes, Falcon 9 can carry human-capable spacecraft.  I'm not that up to date on the intended uses for the Skylon, but would it be able to carry human-capable spacecraft?

Yes. Skylon is intended and designed from the beginning to carry humans and for "aircraft-like" operations.

That video does show "aircraft-like" operations (i.e. like airliners, passengers have no escape system in flight), but it did not answer my question, which was whether Sklyon could carry human-capable spacecraft.  What was shown in the video was a module being carried as cargo, not a spacecraft being carried as cargo - there is a difference.

But the cargo area looks like it could carry a good sized spacecraft, assuming there are no limitations other than size.

I will say though that the Skylon, assuming the ISS is still in operation, will never dock with the ISS.  As I recall the Shuttle caused too much stress on the ISS "frame" during all the times it docked with the ISS, and the Skylon would have a much larger bending moment to be concerned about.  But if the Skylon carried a passenger-carrying spacecraft to orbit, that spacecraft would be able to dock with the ISS with no issue.

You don't seem to know much about it! 

Didn't I state that in my question??

Yes, but it's somewhat surprising given how many posts you've made on a thread about Skylon that you don't know much about it.

For example, while Skylon is twice as long as the Shuttle Orbiter it has a lower mass and the majority of that mass (engines, wings, payload bay, payload, landing gear) is situated at its centre in line with the docking port near its centre of mass, while the Orbiter had wings, engines and tail at one end with the docking port at the other so with out actually calculating it it's not immediately apparent Skylon's bending moment would be higher.
Without actually knowing much about it you can't just say something is or isn't the case.

Payload bay  dimensions are 4.8m diameter 13m length with some restrictions on mass distribution. I think both CST and Dragon should fit but that Dream Chaser is too wide, unless those wings fold.

[Alpha_Centauri]

That was my impression too. I can only imagine that OA is trying to position itself to be a Skylon launch provider and this is their game plan to amass sufficient operational experience with htol launch and SABRE to do that by the time Skylon's become available.

It does seem like a front for the various consortium members, a way to integrate their efforts, particularly consider how quickly it received a government grant for the FSPLUK research given the company was created only last year and is headed by a former BAE marketing man.  Well, we'll see soon enough how serious they are as they want to launch Blue Boomerang by 2020...

[lkm]

That was my impression too. I can only imagine that OA is trying to position itself to be a Skylon launch provider and this is their game plan to amass sufficient operational experience with htol launch and SABRE to do that by the time Skylon's become available.

It does seem like a front for the various consortium members, a way to integrate their efforts, particularly consider how quickly it received a government grant for the FSPLUK research given the company was created only last year and is headed by a former BAE marketing man.  Well, we'll see soon enough how serious they are as they want to launch Blue Boomerang by 2020...

I think it's hard to denying that there has been a much increased interest in having an industrial policy in the U.K. Government over the last decade and the role of the state in investing in key technologies and infrastructure, especially when it comes Space.
The bradspace presentation made a convincing case that access to space is now UK policy and to that end I think government is stuck between intellectually wanting to invest in getting  Skylon made and sticker shock at the cost, but beyond that what government doesn't want to see is Skylon getting built but no UK launch provider emerging to operate it, that would be embarrassing.

[john smith 19]

but it did not answer my question, which was whether Sklyon could carry human-capable spacecraft.  What was shown in the video was a module being carried as cargo, not a spacecraft being carried as cargo - there is a difference.

They were presuming you would extrapolate that a vehicle viewed as safe enough to carry people to orbit would be safe enough to carry a spacecraft carrying people to orbit.

But the cargo area looks like it could carry a good sized spacecraft, assuming there are no limitations other than size.

Skylon's designed payload size is 13m in length and 4.7m in diameter. That's 42.65 feet in length by 15.41 feet in diameter.

I will say though that the Skylon, assuming the ISS is still in operation, will never dock with the ISS.  As I recall the Shuttle caused too much stress on the ISS "frame" during all the times it docked with the ISS, and the Skylon would have a much larger bending moment to be concerned about.  But if the Skylon carried a passenger-carrying spacecraft to orbit, that spacecraft would be able to dock with the ISS with no issue.

Where was this reported? I don't recall this as ever being an issue in operation.

If you've viewed the video you'll know the airlock is canted at an angle and extendable from the top of the PLB. It's canted to allow 2 Skylons to dock lock to lock. If stress on the dock is an issue then logically the coupling needs to be more compliant.

[high road]

COTS was not a subsidy.  The proposed funding of REL/SABRE/Skylon by the UK would be a subsidy.

Surely continuing to use Soyuz is a viable option...

Viable, sure if the goal is to keep the status quo on the ISS.  But the Soyuz can only carry three people, which has to include at least one Russian spacecraft commander, and there is little room for any down mass cargo.

Commercial Crew vehicles will be able to carry at least four people for NASA's needs, while also carrying up and down mass cargo.  With the ability to carry four people up, and to keep them there, the crew complement of the ISS can be raised from a limit of 6 to at least 7 - and that means a potential increase in science time of almost 50%.  So Commercial Crew is not also a potential money saver over time, but it allows the ISS to be better utilized.

Skylon would also be an improvement over todays existing launchers... If the 'need' can be so vague, any new technology is an improvement.

...and must be quite a lot cheaper than designing new rockets?

Oh, I see, you think the Falcon 9 and the Atlas V are new rockets?  They were not built specifically for carrying ISS servicing spacecraft, but for general payloads - which can include human spacecraft.

The only new hardware being developed for the Commercial Crew program are the crew-carrying spacecraft.

From the COTS report:

At the time of the COTS award, SpaceX was still developing its Falcon 1 rocket, named for the Millennium
Falcon spacecraft commanded by Han Solo in the popular Star Wars film.

Edit: link to the report, for those of you who managed to miss the first three results when googling 'COTS NASA'.

https://www.nasa.gov/content/nasa-releases-cots-final-report

Yes, it was a new rocket. Yes, NASA covered 47% of the development cost of the Dragon launch system. Whether that includes the Falcon 9 or not is beyond the level of detail of the report (or lack of time on my part to read in detail). Yes, it was for national pride and transfering some of NASA's 'logistics' over to the commercial sector. That's not a bad thing.

Would Skylon succeed by having such state support? Probably not. Most of the COTS participants didn't, and they were arguably much less revolutionary. But would the UK, or even ESA as a whole benefit from such an approach? Hell yes. Although probably considerably less than the US. For several reasons, most importantly the one you mention: the UK has no history of sending meaningful amounts of payload to orbit. The fact that there is a garanteed paying customer attracts much more investment. Otherwise, Skylon becomes a 'HTOL to nowhere'.

[john smith 19]

the UK has no history of sending meaningful amounts of payload to orbit. The fact that there is a garanteed paying customer attracts much more investment. Otherwise, Skylon becomes a 'HTOL to nowhere'.

Are you talking about the UK Govt or UK industry in general. If the former you might like to look up "Skynet communications system"

If the latter you should look up who mfg a large portion of the Geo comm sats in orbit. It's a multi $Bn industry in the UK.

What the HMG has shied away from is the LV part of the industry. Following ELDO they did not join the Ariane  development process (although Ariane 5 does have some UK built parts, like the gas generator exhaust piping).

What history has shown is the benefit of having an "anchor customer" like DARPA for Pegasus. In REL's case that would be for a purchase of Skylon, at an inflation adjusted price, if it met its performance goals.

Subsidy? Support? Commercial transaction?

[lkm]

the UK has no history of sending meaningful amounts of payload to orbit. The fact that there is a garanteed paying customer attracts much more investment. Otherwise, Skylon becomes a 'HTOL to nowhere'.

Are you talking about the UK Govt or UK industry in general. If the former you might like to look up "Skynet communications system"

If the latter you should look up who mfg a large portion of the Geo comm sats in orbit. It's a multi $Bn industry in the UK.

What the HMG has shied away from is the LV part of the industry. Following ELDO they did not join the Ariane  development process (although Ariane 5 does have some UK built parts, like the gas generator exhaust piping).

What history has shown is the benefit of having an "anchor customer" like DARPA for Pegasus. In REL's case that would be for a purchase of Skylon, at an inflation adjusted price, if it met its performance goals.

Subsidy? Support? Commercial transaction?

I would have thought that should the U.K. ever come round to that sort of support for Skylon it would be in the form of a PPP like the one that funded Skynet. They would contract for so many Skylon launches/year so much responsive  availablity with the excess capacity being available for commercial sale and a consortium would then be formed to privately purchase the Skylon's and operate the launch company, which is how Skynet is managed.
I just really want them to launch from Ascension.

[Coastal Ron]

Skylon would also be an improvement over todays existing launchers...

My view has always been that it has been the cost of moving mass to space that has blocked our ability to expand humanity out into space.  Essentially that it doesn't matter what the technology is, the entire cost to move a kg of mass to space has to drop substantially over time.

So I'm assuming the improvement you are suggesting is specifically related to the cost of moving mass to space, and not what the technology is?

If the 'need' can be so vague, any new technology is an improvement.

I define "need" using purely supply & demand terms, which is technology agnostic.

The only new hardware being developed for the Commercial Crew program are the crew-carrying spacecraft.

From the COTS report:

At the time of the COTS award, SpaceX was still developing its Falcon 1 rocket, named for the Millennium
Falcon spacecraft commanded by Han Solo in the popular Star Wars film.

However SpaceX did not bid the Falcon 1, they already had the Falcon 9 designed and defined enough that they could use it in their COTS and CRS proposals.

Whether that includes the Falcon 9 or not is beyond the level of detail of the report (or lack of time on my part to read in detail).

You didn't provide a link to the report you are citing, so I can't validate your information.  However if you look at the COTS payment milestone schedule you'll see that no money was provided specifically for Falcon 9 development.  See the following GAO report from 2009 to validate what I'm saying:

Commercial Partners Are Making Progress, but Face Aggressive Schedules to Demonstrate Critical Space Station Cargo Transport Capabilities

The SpaceX milestone schedules, and corresponding payments, start on page 19.  Hopefully this puts this issue to rest - NASA did not pay to develop the Falcon 9.

Yes, it was for national pride and transfering some of NASA's 'logistics' over to the commercial sector. That's not a bad thing.

"National pride" had nothing to do with it.  NASA is the majority owner of the ISS, and if it didn't take steps to create a cargo resupply system to take over for after the end of the Shuttle, the ISS may not have continued.  And remember that the SpaceX Dragon is the only vehicle that could replace the down-mass need from the ISS, so it's not like there were valid alternatives available to ensure redundant services.

Would Skylon succeed by having such state support? Probably not.

I've never had an issue with the UK supporting the Skylon.  I've only had an issue with the claim that the Falcon 9 development was state supported.

Most of the COTS participants didn't, and they were arguably much less revolutionary.

You've actually touched on the core of the issue here.  The other COTS participants didn't continue building their proposed capabilities because there wasn't a market outside of the ISS to target.  And "revolutionary" or not, their hardware solutions would have worked just fine, but they were not as cost competitive as Orbital and SpaceX - and money is the deciding factor in a competitive environment.

But would the UK, or even ESA as a whole benefit from such an approach? Hell yes.

Here in the U.S. we have a thing called "pork politics", which is government spending that is based on politics, not need.  My hope would be that the money spent on the Skylon would result in a net add to the GDP of the UK, but that would only happen if there was a "demand" for it's capabilities.

Hopefully there is, but just because something is "revolutionary" doesn't mean that there is.

My $0.02

[RanulfC]

SSTO tends to assume a higher margin for 'safety' than a multistage design but in fact there is no basis for that assumption other than the "fact" that over their evolution most OTHER transport systems are 'technically' "single-stage" vehicles that have become much safer over time. Note that is OVER TIME during which they continually got safer and more efficient as they evolved.

What makes them safer is the elimination of staging and engine ignition events, both of which are complex and have  to work. This is called "intact abort." AFAIK it may be possible to add that to a TSTO if both stages run the same propellants, which after the retirement of Titan had not been the case in Western practice (with the exception of some Ariane upper stages). Historical (Bono style VTOL) expected to do limited engine restart of a segmented engine.

"Intact Abort" is a built in and design feature and is not limited to any type of design, especially in space launch. And no even if both stages run on different propellants "intact abort" can be designed in. Staging IS in fact a 'complication' but is a very proven and effective technique and would be more so in a fully reusable TSTO design.

But the wings let you glide in a way that does not exist for any VTOL concept moving below about M5. That gives you time and control.

Again that's the main "wings-and-wheels" argument which is questionable for space launch purposes. If you assume you need them then they are great, if you don't they have less value than it would seem. Having them makes you 'safer' only under certain circumstances and for certain values of 'safer' since you have to dump propellant AND find a suitable place to set down within gliding range as compared to a VTOL spot of flat ground.

BTW REL's goal has always been to accumulate flight hours and once they are high enough (and it's high by ELV standards but not by aircraft) get it certified safe for passengers.

Which is nice and all but kind of hard to understand since most international flight certification organizations have come right out and said that no "launch vehicle" is going to be certified in that manner because they are NOT aircraft. The only possible exceptions are aircraft used as carrier vehicles for launching vehicles which specifically applies to the carrier AIRCRAFT because it IS an aircraft. Carried launch vehicles, (such as Spaceship 2 for example) are NOT planned to be given aircraft like certifications in the foreseeable future.

And that's the real issue for anyone looking to massively raise the number of people in space. 

While you're using an ICBM architecture you will always need an artillery range in case  of a launch mishap.  Musk plans to side step this by putting a lot of people up at a time and (AFAIK) making the whole 2nd stage an LES.

Actually ANY launch system has 'range' requirements this isn't as restrictive as most people think either. Skylon is no different as it has to have cleared airspace corridors and ground track, though like most space launch systems it will get away with much of this by going over water. Every transportation system has such limitations imposed by public safety and good sense. The public tends to allow variance over time as the system improves but for the most part space launch is always going to require more separation and a bigger buffer zone. If you want to launch more people or cargo you can always use multiple pads and that actually reduces your range overhead by splitting it up among multiple users per day.

Launch CAPACITY isn't the problem though it is the general requirements and economics that are holding back space development. Find a reason to launch more and the capability will be there.

Randy

[knowles2]

Nothing really new, but I thought it was an interesting summary of the UK government thinking on space.

http://spacenews.com/britain-endorses-esa-promises-increased-export-credit-support-for-industry/

They are blaming Reaction Engine and EU for the slow release of government funds for Sabre engine development, but that pretty normal for this government, everyone but themselves are to blame.

[RanulfC]

Something I'd like people to keep in mind.  Let's just repeat that for people who think either of them looked at Skylon:

neither Musk or Beezos did much 'due-diligence' work on anything OTHER than the concepts they went forward with.

   Repeating such an assertion does not make it any more true.

Repeating the truth no matter how much some people may not like it does not make the statement false either

Both projects started with clear bias which were stated and quite visible up-front.

That's utter nonsense.  If you think that's true, cite a reference that shows that bias.

The design evolution of both SX and BO are pretty clear and show no variation from the original TSTO VTL rocket powered design. Both Musk and Bezos said they did not even consider wings or any other propulsion system other than rockets. Not sure how much more reference you think you might need.

No concepts beyond those already in mind were considered or 'traded' and this has been stated by both SX and BO.

If you're going to claim SpaceX and Blue Origin said something, you'd better be prepared to cite a reference to prove it.[/quote]

They both started from rocket powered, vertical take off designs. Bezos actually used a jet-powered VTOL test bed but stated he had no interest in pursuing or expanding on an air-breathing design when he donated it to a museum.

Again this is all public information along with both rejecting any SSTO designs or concepts BEFORE beginning trade studies.

Neither considers Skylon as a viable concept,

Finally, you said something that is true.  But you've apparently misunderstood it.

To consider Skylon not to be a viable concept is to have a judgement about it.  To have a judgement about it means it was considered.[/quote]

They in fact did not consider it as Musk was unaware of it till asked about it at which point he noted that he did not believe air-breathing of any type had any utility in space launch. Bezos does not believe that Skylon, (note not SABRE) is not a viable concept because it is an SSTO and he does not believe those can be made to work. (Note that this IS a company bias as I know an engineer who applied for a job early on with BO. He mentioned several SSTO concepts and projects he'd worked on but was specifically told that there was no interest in them)

Their "judgment" was they didn't consider them and therefore were not going to consider the concept, propulsion system, or even think about them. I have not 'misunderstood' anything but you, (like many others) seem to think that both SX and BO were much more 'thorough' in their design considerations than they obviously were.

Take for example nuclear thermal propulsion, Musk has never rejected it yet it was never considered for any of his projects. He actually took the time to do some research on the subject before answering a random question asked at a conference. He tossed off a comment on Skylon as soon as he heard "SSTO" and "Air Breathing" without pausing for breath.

more to the point neither has any consideration that an air-breathing rocket engine capable of operation from zero-to-Mach 20 has any 'use' in their plans.

Of course they don't have it in their plans -- they considered it and rejected it early on. That's not evidence of a bias.[/quote]

Actually it is but there is no evidence they "considered" it all, let alone rejected it as part of a trade or comparison. Neither one "considered" anything but a straight rocket powered design at any point and this is obvious in their planning and presentations from the start. This is actually a case-study of 'bias' as they in fact did NOT consider such technology. At all.

Both Musk and Beezos started with an idea of what they wanted in the end to have, it is no surprise that they ended up with pretty much what they wanted in the first place.

Nonsense. What they started with was a dissatisfaction with the current state of the launch industry and a desire to find some way to revolutionize it to lower costs and expand access. They looked into how to revolutionize the launch industry and both independently came to the same conclusion: vertical launch and landing of chemical two-stage reusable rockets.[/quote]

Sorry they didn't. Musk started with a possibly salvageable, conventional rocket design and then bowed to technological difficulties and made a conventional fully expendable TSTO rocket that while much lower cost than conventional LVs was essentially a cheaper version of those vehicles. He did NOT start off 'revolutionize' the launch industry but to lower the cost of launch itself. He then planned a larger vehicle (Falcon-9) that would eventually be fully reusable but has not managed to make that goal. Yet Yes he now plans on making a fully reusable vehicle but that wasn't obvious to his needs from the start.

Bezos on the other hand wanted a fully reusable sub-orbital launch vehicle and again took his cue from the industry standard of a vertical launched rocket powered vehicle. It is probable that his future orbital vehicle will continue to use rockets and launch and land vertically but again he's no where near that point yet.

So both parties STARTED with the industry standard of a vertically launched, rocket powered vehicle with no consideration of any other propulsion or configuration. So what part of my original statement was 'nonsense' in any way?

Neither one of them had any background in rockets.  The idea that they would start out with vertical take-off and landing reusable rockets as a preconceived idea makes no sense whatsoever.

Really? Considering their original engineering expertise was derived from people who had worked on vertical take off and landing rocket programs previously and they 'deferred' to those experts because, (as you note) they themselves were not experts and both stated early on that wings or lifting return were NOT considered at any point at what point does my statement make 'no' sense? (And point of fact that was EXACTLY what Bezos stated he was aiming for FROM THE BEGINING so I would think you might want to review what has been said before calling someone's observations of the FACTS 'nonsense' )

There is no evidence that they seriously considered any concepts or ideas that did not fit their already pre-conceived ideas on what they would end up with, (which oddly enough is something REL is accused of doing as if it were a "bad" thing) and there IS evidence that the only 'trades' done were within the already defined parameters rather than anything more general and inclusive.

If you're going to claim there is evidence, present that evidence.[/quote]

Feel free to actually review both Musk's and Bezos' early statements on what they expected from their designs and the designs themselves. The evidence is quite obvious and readily available. And the main point still stands quite well; Neither has any interest or desire to move outside their bias' and so never even looked at any type of air-breathing or winged vehicle because those did not fit the bias they had established.

Should they ever actually consider and research Skylon or the SABRE engine I would gladly accept their opinion on them but since they have not done so simply tossing off a statement of their 'belief' as an opinion does not give them any more credibility on the subject than the majority of posters here.

Randy

[Paul451]

Just pedantically, since I don't have a horse in this fight,

If you think that's true, cite a reference that shows that bias.

[...] Both Musk and Bezos said they did not even consider wings or any other propulsion system other than rockets. Not sure how much more reference you think you might need.

Since you didn't provide any references, I'm going to guess his answer would be, "More than that."

No concepts beyond those already in mind were considered or 'traded' and this has been stated by both SX and BO.

If you're going to claim SpaceX and Blue Origin said something, you'd better be prepared to cite a reference to prove it.

Bezos [...] stated he had no interest in pursuing or expanding on an air-breathing design when he donated it to a museum.
Again this is all public information along with both rejecting any SSTO designs or concepts BEFORE beginning trade studies.

Again, do you have an actual reference for them both rejecting anything except TSTO before they started trades.

You are not just saying "This is my impression given the fairly mundane TSTO designs they ended up with", you're explicitly claiming "Both Musk and Bezos said...".

Hence...

Feel free to actually review both Musk's and Bezos' early statements

...directing someone else to go and look for evidence to support your claim is kind of rich.

Because if...

The evidence is quite obvious and readily available.

...then it should be a snap for you to support your own claims.

[Khadgars]

Randy, I think you are selling SX and BO considerations and analysis a bit short.  No one here is privy to the internal discussions both company's had, and to be fair this discussion is pure speculative on all of our parts.  But Elons quote clearly shows he looked at the numbers, the complexity of adding a jet engine with a rocket engine and came to the conclusion that the payoff had to be way to high for it to makes sense.  To me that's pretty clear, and he leaves the door open to being wrong.