The Reaction Engines Skylon Master Thread (1)

[yg1968]

I have trouble getting excited about Skylon. IIRC, it will cost around $12B to develop. They are not going to be many investors willing to invest that kind of money into it.

[Lars_J]

In other words, they have to sell two Skylons per year to make a profit.

Nope, since there are other uses for the technology than Skylons that will mean a secondary stream of income for the company.

What secondary stream of income? They don't even have a *primary* stream of income yet.

There is a heck of a lots of "IF"s involved.

[Andrew_W]

b: anything can be packaged into 15 tonne payloads (see project TROY on REL website)

I've argued that it makes a lot of sense, if you want to make transporting stuff into space routine, to standardize payloads to the sizes of the common shipping container, some assembly may be required at destination.

[Longstaff]

Hi,

A query about the discussion on the need not to fly supersonic over land.

On the Nasa site
http://www.nasa.gov/centers/dryden/news/FactSheets/FS-016-DFRC.html

It states that

"Overpressures of 1 to 2 pounds are produced by supersonic aircraft flying at normal operating altitudes. Some public reaction could be expected between 1.5 and 2 pounds."


It then provides a list of typical overpressure per aircraft types at varying height levels:

SR-71:             0.9 pounds, speed of Mach 3, 80,000 feet
Concorde SST: 1.94 pounds, speed of Mach 2, 52,000 feet
F-104:             0.8 pounds, speed of Mach 1.93, 48,000 feet


In this context if Skylon is flying at 25KM = 80,000 feet for intercontinental trips - isnt the sonic boom a non issue until landing approaches where it would slow subsonic near populated areas at low altitudes??

From memory, our overpressure for the A2 was just over 1 psi at cruise. But this was still thought to be too much (shades of Concorde). Any supersonic flight was to be over water (including approach).

 

[yg1968]

Here is the press release from Skylon:
http://www.reactionengines.co.uk/news_updates.html
http://www.reactionengines.co.uk/press_release/PRESS%20RELEASE%20-%20THE%20BIGGESTBREAKTHROUGH%20IN%20PROPULSION%20-%2028%20November%202012.pdf

[Andrew_W]

http://www.transport-research.info/Upload/Documents/201211/20121105_121021_14924_Final_Activity_Report.pdf

Routes
Commercial civil transport aircraft, flying subsonically, normally follow a “great circle” route between the
airports of departure and arrival, once they are clear of local traffic. However in the case of supersonic
aircraft there is the complication of the “sonic boom”, or ground overpressure produced by supersonic flight.
Various tests show broad agreement that an overpressure below 50 Pa is tolerable for regular overflights of
populated areas (although there appears to be no safe level which will eliminate complaints) [D2.1.2].
Unfortunately practical civil transports produce overpressures above this level. For example Concorde
generated an overpressure of about 93 Pa, which restricted supersonic flight to over water regions only and
effectively reduced its commercial viability. Current overpressure estimates for the LAPCAT configuration A2
vehicle suggest that at the start of Mach 5 cruise the overpressure will be about 85 Pa under the ground
track, reducing to about 70 Pa at mid cruise. Therefore preliminary route planning for the LAPCAT vehicle
has assumed that supersonic flight is only possible over regions of very low population density (oceans and
the North and South Poles).

[93143]

I saw it and I doubted the graph. Who makes these statistics?
Probably the same people on wallstreet that gave us the financial crisis.

Its why Burt Rutan called NASA "NaySay". This sort of conservative thinking has not gotten us anywhere in 30 years.

On what grounds do you dispute the findings of the market study?  (It is a little outdated, but I wouldn't expect it to be order-of-magnitude wrong.)

Skylon and reusable Falcon are both expected to come in below the price breakpoint, so I'm not sure what you're complaining about...

Reference here:

http://www.spacefuture.com/archive/designing_reusable_launch_vehicles_for_future_space_markets.shtml

Original study here:

http://www.hq.nasa.gov/webaccess/CommSpaceTrans/

[Rugoz]

In other words, they have to sell two Skylons per year to make a profit.

How long it takes the purchasers to churn through the advertised 200 flights per airframe is beside the point.

? The 1.8+ billion profit is PER year, is you assume they have a monopoly on skylon technology for 10 years (for 20 years its 1.1772b annually, very rough estimates based on my own fantasy numbers of course).

You can't sell skylons at a price higher than operators, who offer the launch service, are willing to pay for. But as the launch service providers are competitive, you will, in theory, extract all their profit.

he US military and NASA already do

us military launches on anything but delta and atlas? Also spacex is an american company. But afaik esa does many launches on soyuz.

If skylon can do more launches, then, assuming the competition is still expensive, skylon could be a good business.

For example. 10m for skylon launch. 50m offer from competition. demand for 50+ launches (per year) at 50m. Makes almost 2billion profit if you price slightly lower to capture the market. Something like that .

[93143]

The 1.8+ billion profit is PER year

IIRC REL are aiming for a unit price in the range of $1B, a lot of which is amortized development cost.  They believe a production run of 30 vehicles is a reasonable goal.

The operators can then take their own time making back the purchase price, taking into account the additional ~$1B of lifetime maintenance and operations costs.  REL don't care how fast launches happen or what the per-launch price is because they don't charge per launch.

Skylon's economic model has been assessed independently by London Economics, and it was deemed to be robust.

[Rugoz]

^

I'll quote

In fact if 30 vehicles are produced and using the official UK government discount figure of 3.5% the cost recovery per vehicle is $0.81bn.

So if they produce 30 vehicles over 20 (my guess) years thats 30*0.81/20 = 1.2b profit per year. With a 3.5% discount rate that sounds reasonable, however thats a rate only governments get.

They need to sell 30 vehicles, so 200 launches * 30 is 6000 launches. That is alot. Maybe they think selling the skylon cheap and creating more demand for satellites is the optimal strategy.

Skylon's economic model has been assessed independently by London Economics, and it was deemed to be robust.

With government involvement, its certainly robust. Spillovers, cheap financing and secured military/gov. launches.

[QuantumG]

Let's all just hope that there will be a market for that many flights in the near future.. that'd be great.

[93143]

That's 6000 potential flights, over an undefined timeframe.  It's not like Skylon is being designed to self-destruct after three years.

And yes, it would be great.  Skylon holds the promise of dramatically reducing launch costs and opening up space like never before.  But it can succeed economically without doing so.  The business model doesn't collapse until the total sales drop below about 10, with a pessimistic discount rate.

And what's this about a 20-year production run for only 30 vehicles?  Seems an odd choice for a random guess...

[Elmar Moelzer]

On what grounds do you dispute the findings of the market study?  (It is a little outdated, but I wouldn't expect it to be order-of-magnitude wrong.)

Tell me one market where the behaviour was like that in the past!

Skylon and reusable Falcon are both expected to come in below the price breakpoint, so I'm not sure what you're complaining about...

I wasnt the one claiming that the market was not elastic enough for them.

[ArbitraryConstant]

My point is that Elon is taking the traditional path, but needs to be more up-to-date on the competition down the road.

AFAICT he has looked at it, and doesn't think breathing air offers sufficient advantages to be preferable to the alternative of just making the launcher bigger. Nothing so far excludes that conclusion being true.

Yes, he's said something similar about air launch. Similar purported advantages, similar criticism.

Any attempt to deal with the atmosphere more than the absolute minimum has to be weighed against the cost of just shoving a few percent more propellant mass off the pad the old fashioned way. I think Musk's point is that a few percent more propellant is simple and cheap, and doing stuff that's not simple and cheap is unlikely to end up working better.

[Rugoz]

And what's this about a 20-year production run for only 30 vehicles?  Seems an odd choice for a random guess...

Well I didn't choose 20 years to make it fit my numbers if that is what you mean  (Actually it doesn't, because they assume a lower discount rate, so lower production run would be closer).

No I mean I think its reasonable to distribute skylon production more or less over the whole program duration, which I assumed to be around 30 years. Last production after 20 years.

But it can succeed economically without doing so.  The business model doesn't collapse until the total sales drop below about 10, with a pessimistic discount rate.

Yeah if you make skylon more expensive. Will operators still pay for it? Depends on launch market. They don't really write about that in the report.

[Jim]

1.  Not it is not unproven!

2.  The Mach2 flight was too little an improvement for the cost.

3.  irrelevant to the question whether the market will react to lower prices.

Wrong on all accounts, again.

1.  How many suborbital flights happened in the last five years?  How many suppliers are in routine operations?  I rest my case.

2. Wrong, it shows a trend.

3.  Wrong.  The costs are unknown.  There for the market is also.

[Jim]

I saw it and I doubted the graph. Who makes these statistics?
Probably the same people on wallstreet that gave us the financial crisis.

And how is Skylon any different than the people that "developed" cold fusion in the 80's?

And who are you do doubt the graph?

[Jim]

It then provides a list of typical overpressure per aircraft types at varying height levels:

SR-71:             0.9 pounds, speed of Mach 3, 80,000 feet
Concorde SST: 1.94 pounds, speed of Mach 2, 52,000 feet
F-104:             0.8 pounds, speed of Mach 1.93, 48,000 feet


In this context if Skylon is flying at 25KM = 80,000 feet for intercontinental trips - isnt the sonic boom a non issue until landing approaches where it would slow subsonic near populated areas at low altitudes??

No, the larger the aircraft, the greater the overpressure

[Elmar Moelzer]

How many suborbital flights happened in the last five years?  How many suppliers are in routine operations?  I rest my case.

They still have preorders. The preorders proof the point. I rest my case!

Wrong, it shows a trend.

Nonsense! You can not devise a trend from a single data point!

Wrong.  The costs are unknown.  There for the market is also.

Nonsense again!

[Turbomotive]

I saw it and I doubted the graph. Who makes these statistics?
Probably the same people on wallstreet that gave us the financial crisis.

And how is Skylon any different than the people that "developed" cold fusion in the 80's?

And who are you do doubt the graph?

given the resources and know how, anyone should be able to repeat REL's precooler tests. On the other hand, no one has been able to recreate cold fusion, because it was a scam.

I like that graph. if i read it correctly, you are in the money with launch cost < $1,800/kg, by my calculation, the cost to GSO with reusable SUS.