The Reaction Engines Skylon Master Thread (5)

[pippin]

Also "every other in the world" is a bit too high of a call, I know other transport systems operated by their manufacturers.

[Vultur]

Historically people seem to have been thinking that you can gradually evolve to full reusability but SX have demonstrated that does not work.

This seems like a premature conclusion. Elon Musk has said that FH could be made fully reusable but they want to spend resources on BFR (which will be fully reusable) instead. That doesn't seem to me to rule out a future fully reusable vehicle in the FH class once BFR is developed.

The real issue would probably be that under US ITAR laws flying down to the Equator would be viewed as "exporting" the payload

What's the self-ferry range? Could it reach Hawaii from the US west coast?

[93143]

Could it reach Hawaii from the US west coast?

I don't recall if the ferry range has been specified; it was supposed to be "roughly transatlantic" last I recall, but Hawaii is closer to California than Ireland is to Maine.  If it can reach French Guiana from a point in the U.K., Hawaii from Mississippi (never mind California) should be perfectly possible.

[Impaler]

Why?

The status keeps the people who can already justify launching satellites (or get some government to fund them) launching things already.  As for everyone else they can't afford to launch so (basically) they don't count the the main ELV mfg mind set really could not care less.

The Why is blindingly obvious, falling short in the 5 criteria I specified, cheap, common, safe, reliable, competitive and regulated.  If it's not cheap, common, regulated and safe the volume will be too low to justify the manufacture of more then a handful of vehicles and the manufacturer would simply fold after completing them.  If it's not reliable the operator will have to have the manufacturer literally live onsite keeping the vehicle alive at such a high cost that it becomes a de-facto lease rather then a purchase (which while it is a viable business model similar to software, it's not what your describing).  If it's not competitive (aka other manufacturer) then operators will not want to become dependent on a single supplier or will demand an exclusivity agreement with the manufacturer.

Hmm. Let me see. I am a government that wants to launch payloads into space on a semi regular basis. Do I
a) Keep handing $60-150m to a foreign business for a ticket with a roughly a 1 in 50 to 1 in 75 chance of being blown to bits that will launch it at their convenience
or
b) Commit to paying quite a lot more (but potentially spread out over a decade or more, roughly $150m/year or 1/120 of NASA's budget) for a vehicle that can launch more or less when we want it to (since it's preped in our country, self ferries to the Equator, get a top up and goes), carries our payload as prime and for a bit extra can give us an upper stage that will allow us to run a Moon or planetary exploration programme.

As a side benefit we can also sell excess capacity to other customers while new projects are in development and if we so choose sell it as an asset (the nearest people come to this is selling either the data from satellites they own or the orbital slots for GEO comm sats)

Decisions, decisions.

No one will believe any reliability estimate for any radically new vehicle until it has gone through dozens of flights, and if your trying to prove airplane levels of safety and not-blowing-up your looking at hundreds of flights before a buyer would be willing to just plunk down the purchase price and accept the chance of loosing the whole vehicle.

Your switching to talking about government space-agency ownership rather then multi-national commercial, but your explanation contains it's own undoing.  One nation is supposed to buy the thing and then sell the capacity they don't use.  But why doesn't the buying nation just let someone else be the sucker and THEY can buy the spare capacity as need dictates.  Everyone who can't fully utilize a whole vehicle (maybe 2-3 agencies tops) is in the same boat so their is no reason for anyone to get their own, they would rather purchase flights from an international consortium which means your looking at a handful of vehicles for the whole world market which isn't enough to justify the manufacturers business.

Also no national space agency just buys hardware like that from another country, the ALWAYS develop their own capabilities IN HOUSE, even if they are primitive at first.  Because any piece of high technology requires a huge intellectual and manufacturing army to maintain, you can't just buy something and become empowered, you need your own space industry and the best way to do that is to grow it organically.

[93143]

No one will believe any reliability estimate for any radically new vehicle until it has gone through dozens of flights, and if your trying to prove airplane levels of safety and not-blowing-up your looking at hundreds of flights before a buyer would be willing to just plunk down the purchase price and accept the chance of loosing the whole vehicle.

The test programme is ~400 flights with just two vehicles, including a couple dozen abort tests.

[john smith 19]

The test programme is ~400 flights with just two vehicles, including a couple dozen abort tests.

The OP this is a reply to seems to be more of a writer than a reader. 

[john smith 19]

What I'm saying is that it's not some kind of fairy dust which magically removes a huge amount of cost just by splitting up the business model.

It does split the pay back into a few big chunks, rather than a great many little ones.

Will it be dramatically cheaper? Nah.

Based on what?

When there is one operator with one Skylon I don't expect them to charge below market rate (which will not be SX's asking price for any payload > 13 tonnes and for a comm sat will be more like the $100m Shotwell stated SX charge for GTO launches)

Which will recover the cost of buying a Skylon in a fairly small number of launches.

The question becomes what happens when multiple operators are in the field, which is what REL want and need.

Note this excludes governments who want a launch-on-demand capability. From REL's PoV it does not matter  how often they launch, since they've already bought the vehicle and its the customers privilege to when they launch their next payload.

[john smith 19]

Also "every other in the world" is a bit too high of a call, I know other transport systems operated by their manufacturers.

Which are?

The only ones I can think of is the Antonov "Spirit" operated by "Antonov Airlines," and the "Beluga" Airbus parts transporter, which I think is pretty much only used for Airbus business.

Which would just leave every other large aircraft in series production being sold to operators

I'd be very interested to see what vehicles I've missed.

[Lars-J]

I'm glad to hear it, because that is not how you come across when posting.

Like everyone else on any forum, I am responsible for what I write, not for how people read it.

Then you need to be more precise. Just look at this statement that triggered my comment again:

"Skylon is completely reusable. What's tested in certification is what will fly. Exactly what was tested, not a new piece built to the same design."

How am I supposed to interpret that, other than that you are certain that things will turn exactly this way? In your eagerness to convince people, you have a history of expressing certainty where there is little (or none) to be found. This does not make your arguments more persuasive, it has the opposite effect.

[john smith 19]

Then you need to be more precise. Just look at this statement that triggered my comment again:

"Skylon is completely reusable. What's tested in certification is what will fly. Exactly what was tested, not a new piece built to the same design."

How am I supposed to interpret that, other than that you are certain that things will turn exactly this way? In your eagerness to convince people, you have a history of expressing certainty where there is little (or none) to be found. This does not make your arguments more persuasive, it has the opposite effect.

Well you could have interpreted it as REL believing and planning for this outcome, since they expect Skylon to fly like an aircraft. Outside the military most aircraft don't have bits designed to routinely drop off and be replaced, like tanks and RATO packs, for example.

Would you feel better if I preface my remarks with "REL have stated that.." ? I'm not really used to dealing with people whose comprehension needs that much guidance regarding whose PoV is being expressed, but perhaps I'll start factoring your problems into my posting style in future.

Normally I take any companies statements at face value as I don't have any special insight into any business. In the same way as I took REL's on flight testing and certification I took Shotwells comments about being able to do a fully reusable F9 launch for $6m in June 2013. That's, in hindsight, now looks to be a case of "expressing certainty where there is little (or none) to be found"  as well.

Like wise when Musk stated in 2014 that no F9 (or F9 derived) vehicle was going to be fully reusable and it would be the "BFR" that would be fully reusable I also take him at his word.

I've seen speculation that SX will "go back" and make a fully reusable FH, but SX have made no such public statements I'm aware of, so why would anyone think that when the CEO just said the reverse?

I merely re-stated what REL plan and expect to be able to do, just as SX have planned and stated what did expect, and now expect, to do.

[flymetothemoon]

I'm glad to hear it, because that is not how you come across when posting.

Like everyone else on any forum, I am responsible for what I write, not for how people read it.

Then you need to be more precise. Just look at this statement that triggered my comment again:

"Skylon is completely reusable. What's tested in certification is what will fly. Exactly what was tested, not a new piece built to the same design."

How am I supposed to interpret that, other than that you are certain that things will turn exactly this way? In your eagerness to convince people, you have a history of expressing certainty where there is little (or none) to be found. This does not make your arguments more persuasive, it has the opposite effect.

I wish to speak up for John. We know what he means "Skylon AS DESIGNED is completely reusable." This is just pedantry. We'd ALL hate it if everyone had to preface each sentence with some disclaimer or add superfluous words like 'AS DESIGNED' everywhere. We also all know Skylon is much more than a BOTE design or a PowerPoint.

We all get it all already. This is an advanced concepts thread...

[Lars-J]

I wish to speak up for John. We know what he means "Skylon AS DESIGNED is completely reusable." This is just pedantry. We'd ALL hate it if everyone had to preface each sentence with some disclaimer or add superfluous words like 'AS DESIGNED' everywhere. We also all know Skylon is much more than a BOTE design or a PowerPoint.

We all get it all already. This is an advanced concepts thread...

I realize that your mileage may vary at this point, but I don't think it is overly pedantic. This is where advanced concepts are discussed and challenged, not accepted at face value just because somebody makes a claim. 

[Star One]

I wish to speak up for John. We know what he means "Skylon AS DESIGNED is completely reusable." This is just pedantry. We'd ALL hate it if everyone had to preface each sentence with some disclaimer or add superfluous words like 'AS DESIGNED' everywhere. We also all know Skylon is much more than a BOTE design or a PowerPoint.

We all get it all already. This is an advanced concepts thread...

I realize that your mileage may vary at this point, but I don't think it is overly pedantic. This is where advanced concepts are discussed and challenged, not accepted at face value just because somebody makes a claim.

I feel I have to chip in here & defend John as well to add that your original comment did indeed smack of pedantry & your explanation here seems to be little more than arm waving in an attempt to defend the point.

[john smith 19]

This is where advanced concepts are discussed and challenged, not accepted at face value just because somebody makes a claim.

On that basis there is a case for all of SpaceX's reusability work to be moved to this section.

Their claims have been accepted at face value and the landing and the landing of high aspect ratio stages (IE Grasshopper) is definitely on the cutting edge of control systems and flight dynamics work.

AFAIK no one seriously doubted their claims to be able to deliver a reusable F9 upper stage, until they stated they couldn't do it and they'll have to upscale to BFR to do so.

Please note "uneconomic" is an effect of the root causes, not the root cause for cancelling F9 upper stage reuse. That will be around the physics of re entry. Yet no one seems to have thought this was going to be a problem for SX.

Hopefully SX will try again before the year is out and succeed, making it an impressive move forward for expendable technology.

But right now I think you put the whole SX reusability effort under "advanced concepts" as well.

[pippin]

Will it be dramatically cheaper? Nah.

Based on what?

Based on "cost just doesn't go away because you split it up differently". In your own words, you are also more of a writer than a reader, right?

When there is one operator with one Skylon I don't expect them to charge below market rate

I didn't write about price. I wrote about cost. And I explicitly stated that.

All you are doing over and over again is re-stating your same arguments about risk assignment in the investment process but I wasn't talking about that at all. All of this is completely irrelevant for a long-term business case, only recurring cost is relevant then.
No currently flying vehicle is earning it's initial investment.

How about reading and trying to understand my points instead of just re-iterating the same edge-case maths over and over again.

[pippin]

OK, I'll try to explain it one more time...

A Skylon is an investment good. Whatever irrational stuff single players in the market might be prepared to do at some point, if it's going to work in the long term it needs to earn it's total operating cost. Building the thing. Building the operating infrastructure. Flying the thing and it's infrastructure. Repairing them and replacing them end of life with new ones.
No different cost allocation will make any of these smaller. Yes, one party or the other might throw a subsidy or two in there but the same is happening today with the competition. It#s not going to make the cost any smaller, only sometimes the price.

The question will be: what will that total cost be and how much will it be lower compared to existing solutions.

Figures that are mostly irrelevant here are for example initial development cost for the technology because even if you fail to get them recovered the technology is still there.
But you DO need to count the cost to keep the company building the thing around because they will need to keep the knowledge, build replacements, do continuous improvements and so on. They will also need investment (and operating cost) for equipment to build the things around.

The latter is why there's no way in the world SpaceX's reuse scenario could reduce the launch cost 10-fold or so without a dramatic rise in launch rates, the cost of keeping the whole company around doesn't go away just because the company pretty much doesn't have an awful lot to do every day anymore. That's also the very reason why launch costs increased so dramatically with diminishing launch rates at the end of the cold war. All the technology was already developed and even a lot of the LVs already built but all the infrastructure and people were still needed.

Skylon will be no exception to that. If they sell a handful of the things and launch rates don't increase and they stop building them then the cost to keep the existing ones alive will be high. Because you'll still need an awful lot of that infrastructure and people without revenue from new sales.

A good example is Concorde. When that business case came apart due to the oil price shock the initial investment was completely written off (and covered by governments) yet operating the things was still way more expensive than it would have been in a successful scenario because now the few planes flying around needed a standing army of specialists only servicing so few of them.

No, cost reductions have to go along with launch rate increases and dramatic ones, everything else will not make a difference. Especially not accounting practices.

[Space OurSoul]

Had we all seen this presentation from a couple months back with Robert Bond (not Alan)?

https://tv.theiet.org/EmbedPlayer.html?id=6789

The first 25 minutes is your basic intro to Skylon/SABRE, but at 25 minutes there's what I believe is new information, namely that the sub-scale test pre-cooler contains 16,800 tubes totaling 52km (that is, 52,000m) in length. That's pretty astounding, and for me lends not a small amount of significance to REL's accomplishments scaling precooler module manufacturing to production levels. It also matches well with the previously-stated 2,000 km of tubing in a full-sized SABRE.

[Space OurSoul]

Over in an L2 SpaceX thread, Ronpur50 put together a simple size comparison of some extant launchers with some speculation on the SpaceX BFR:

I had this image of some rockets...

With Ron's permission, I elided the L2 work and added the 273-foot Skylon C1, which I present here. Not a small ship.

[Chris Bergin]

Heck! I didn't know Skylon was that big!

PS There was a report to mod about posts getting out of hand with the tone. Remember to keep it civil at all times.

[Ronpur50]

That is huge!