The Reaction Engines Skylon Master Thread (1)

[flymetothemoon]

http://www.reactionengines.co.uk/news_mar12.html

"The initial tests have gone very well and represent a good start to the test campaign which will last several months.

The flow thorough the Pre-cooler has been found to be aerodynamically stable without any significant structural deflection or vibration."

So the tests have started and will last several months. Setting standard project progress expectations to normal, we may perhaps have full results by August.

http://www.rocketeers.co.uk/node/1901

“This space interested investment group has now switched its focus to a next generation Space transportation vehicle with Shuttle capabilities,” added Mr. Holleran. “The group hopes to make announcements as to its intentions end of the first quarter of 2012.”


ref another post in another place, I wonder if this hope might have shifted to end of third quarter?

http://forum.nasaspaceflight.com/index.php?topic=27572.msg842465#msg842465

[simonbp]

Ah ha! Excellent!

After so long and so much theorizing, it's great to see an actual precooler attached to an actual engine, actually cooling the air. Let's hope all the tests go as well as the initial ones!

[Space OurSoul]

Excellent news. I am surprised there is no outer cover over the heat exchanger, and wonder if that's been removed for the picture. I would expect the operators to be very concerned about foreign object damage ( a hail storm would be a disaster ), and further wonder if that missing cover contains some of the secret special sauce that inhibits frost on the exchanger. Anyone have any more-informed thoughts?

I see the tank (presumably He) at the back has some shiny new insulation, so maybe they've actually done some tests with flowing He and not just "warm" air-flow work.

Regardless, all very interesting and exciting. Go Thunderbird Four! Uh, I mean Skylon.

p.s. love the electrical box held up with twine on the right :-)

[john smith 19]

Excellent news. I am surprised there is no outer cover over the heat exchanger, and wonder if that's been removed for the picture. I would expect the operators to be very concerned about foreign object damage ( a hail storm would be a disaster ), and further wonder if that missing cover contains some of the secret special sauce that inhibits frost on the exchanger. Anyone have any more-informed thoughts?

I see the tank (presumably He) at the back has some shiny new insulation, so maybe they've actually done some tests with flowing He and not just "warm" air-flow work.

Given this is a pre-cooler test the frost control system is part of the systems being tested. Ground air density and humidity *will* freeze up the system in seconds *unless* the FC system is installed and running.

The *detail* design of the structure which will house the pre-cooler is going to part of the "Nacelle Test Vehicle" phase of the programme.

Bird strike has been discussed *repeatedly*. Look at the left of this picture

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

Understand this is a cross section and there are likely to be several paths through the machinery which would avoid hitting *any* part of the structure inside the nacelle. It's a problem REL are aware of and confirm it would abort the takeoff. However the vehicle remains *recoverable* and the payload undamaged. In principle the jpayload would be off loaed onto another Skylon ( provided the operator *has* another one) and (provided the window is still open) the takeoff continues.

Frost control is the dirty little secret of *all* air breathing concepts and it's difficulty was one of the reasons that killed the US Hypersonics concepts in the 1960s. (See Facing the heat barrier NASA SP-2007-4232). *Proving* their system viable is one of *the* key milestones. Proving it works at Sea Level (which is worst case for density, air speed and IIRC humidity) should give a *huge* reduction in perceived design risk.

REL appear to be the first to claim success with a flight weight frost control system *anywhere*.

Which *should* make the B9 test stand one of the most closely guarded test areas in the UK outside the nuclear weapons design and production facilities.

In reality it's probably guarded by a night watchmen of pensionable age and his faithful but cross eyed Labrador with a chewed ear, a bent front leg and a touch of mange called "Lucky".

[simonbp]

Proving it works at Sea Level (which is worst case for density, air speed and IIRC humidity) should give a *huge* reduction in perceived design risk.

Yes, also (absolute) humidity. The more air there is, the more water carrying capacity it has.

Speaking as someone who lives at 7,000 ft, it can be annoying trying to make ice cubes, as they'll often sublimate away before I have a chance to use them...

[zaarin]

Which *should* make the B9 test stand one of the most closely guarded test areas in the UK outside the nuclear weapons design and production facilities.

Yep, its inside a military base in Abbingdon and its guarded by a breed of tiny, but aggressive wasps that sting your neck repeatedly.

I wanted a sneak peek, and that's what happened to me.

[simonbp]

Did they have stickers?

[zaarin]

Did they have stickers?

Looks like an interesting read although I wasn't aware of it at the time.

There are also some really fit girls in Abingdon!

 I think whoever controls the operations in Britain's Area 51 is very very clever and maintains a formidable non lethal first layer of counter-intelligence defense from prying eyes.

They also spiked my drink with laxatives and I had an accident that involved me having to buy a new pair of trousers

[WellingtonEast]

Regardless, all very interesting and exciting. Go Thunderbird Four! Uh, I mean Skylon.

Thunderbird Four was a Sub and wasn't Thunderbird Six a bi-plane? so that would make it Thunderbird Seven :-)

[mrflora]

It looks more like Fireball XL5 to me.

Regards,
M.R.F.

[bearshrimp]

This is fascinating and I must say that I am inspired by the idea of a single stage to orbit vehicle (SSTO) that is able to operate from a conventional (improved) runway.  Going through the engineering analysis represented in the proceeding posts is also fascinating.  The engineering detail covered over the past year or so regarding the SABRE engine, structure, fuel and performance is spot on. 

That being said, as a member of an accounting firm I see a flaw in the basic logic.  If the project is intended to be commercial in nature, it must be cost competitive with other means of achieving the same results.  If the result is the delivery of a set mass to LEO for a set cost, I unfortunately can’t see how SKYLON will be cost competitive with established payload delivery systems.

Based on  data provided by the FAA in its quarterly launch reports, the current cost to LEO (in Millions of  2010 USD adjusted for inflation per metric ton) for a SKYLON class payload range from $2.80 (Zenit-2) to $5.11 (Atlas V 531).  Because these systems are well established, we can assume that the development costs are represented in the price paid by commercial customers.  Note that these examples include both Eastern and Western launch systems, a survey of the numbers suggests that Eastern costs are generally lower, but the Atlas V and the systems developed by SpaceX are beginning to reverse that trend.  For example, the Falcon-9 has a current cost of $3.89/mt (from 2009 launch data) and that does not take into account any future reduction for reusability of key components as envisioned by SpaceX leadership.

From what I have seen projected launch price of the C1 version in 1995 was $40M, adjusted for inflation that would give a figure of  $3.89/mt to LEO.  While this is a low cost in the field of current payload delivery systems, it’s not an “order of magnitude” better.  Given that some commercial systems in operation today can beat $3.9/mt, it begs the question, is SKYLON’s true goal to reduce the cost to orbit?

January 2011 in written evidence to parliament REL states that its goal is to reduce the cost of placing satellites into LEO from 15,000GBP /kg to 650GBP/kg or from $23.11/mt to $1.00/mt (in millions of USD, adjusted for inflation to 2010 dollars).  I believe the numbers are based on 30 operational SKYLON aerospace planes operating 70 missions per year with a service cycle of 200 launches for the life of the craft.  So, if I read the report correctly for SKYLON to operate at $1.00/mt would require 30 craft each operating 70 missions per year for a total of 2,100 LEO delivery missions.  Given that there were 23 total launches of commercial LEO payloads in 2010 (per the FAA’s 2010 Commercial Space Transportation Review), and that projected growth is 8%, where will SKYLON find its 2,100 payloads per year? 

I may have misunderstood the 2011 written evidence and the $1.00/mt may be based on 30 craft flying 70 missions total per year.  The issue there is that each SKYLON would only be required to fly 2-3 missions per year in which case a 48 hour turnaround time would not be a consideration.  From looking at the data it appears the allocation of the development cost is based on 30 craft over a 10 year period while the operating costs are based on a 70 mission per year duty cycle.  Under that model the LE estimated that $2B USD of the development cost would be allocated to each vehicle, as each vehicle is rated for 200 missions, the allocation per mission would be roughly $10M USD.

Under optimal conditions we can then assume each SKYLON delivery to cost roughly:
$10M (amortized development cost)
$ 2.25M (amortized construction cost)
$9.5M (operational cost)

For a total of $21.75M per launch or $1.81/mt which is 36% lower than the cost per ton than a Zenit-2 (per 2007 FAA launch report, in adjusted 2010 dollars).

However, if we assume SKYLON came on line in 2022 (10 year gestation period) the demand for LEO payloads would only justify 40 launches in the 1st year of operation given an 8% growth rate.  Over a 10 year period, given a growth rate of 8%, a total of 554 payloads would be available for transport to LEO.  Even if my estimate is a little low, over a 10 year period the market would only demand the services of 4 SKYLONs and that assumes all LEO payloads would be delivered by SKYLON.

On that basis the amortized development cost would rise to $4.5B per SKYLON and $20.6M per mission.  On that basis the SKYLON cost to LEO rises to $2.69/mt which is slightly less than the current cost for Zenit-2 delivery, but is higher than the $2.26/mt cost proposed by SpaceX with its Falcon Heavy. 

As envisioned SKYLON would provide a small benefit over the cost of existing single use delivery systems assuming that the real cost to LEO remains constant between now and when SKYLON becomes operational.  If the costs of single use delivery systems continues to fall over the decade then the financial justification for SKYLON as a commercial delivery system to LEO disappears.

I do see a need for a reusable SSTO vehicle as a method for accomplishing goals that cannot be accomplished by a single use system.  For example, when something needs to be returned from orbit or where manned spaceflight is required a reusable SSTO vehicle may be justified, but as a pure mass-to-orbit commercial delivery system I can’t see SKYLON being the answer.

[93143]

$9.5M (operational cost)

Where did you get this?  I seem to recall REL claiming that at very high flight rates, Skylon could approach a price of $2M per launch for low-value cargo.  It is, after all, basically an airplane...

[bearshrimp]

$9.5M (operational cost)

Where did you get this?  I seem to recall REL claiming that at very high flight rates, Skylon could approach a price of $2M per launch for low-value cargo.  It is, after all, basically an airplane...

On page 18 of the ESA's SKYLON Assessment Report

"Finally REL presented an analysis of operator economics, again with a pessimistic view of trying to capture the existing market without looking at the new and expanded markets that this vehicle could establish. They showed that the estimated operating costs for 70 flights per year could be as low as $9.47M per flight (Jan 2009 prices)."

I think its also interesting that in the report REL estimated a development cost of $12.3B and considers that an "overestimation":

"REL consider this to be a pessimistic estimate as the last entry in table 5-1 shows an overestimating of the cost model as compared to Airbus A380. REL state that this disparity is due to the fact that the model does not take into account modern manufacturing methods which will lower the predicted price. Thus this logic can be applied to the SKYLON development and hence the $12.3Billon cost can be seen as an overestimation."

But...at the 17th International Space Planes and Hypersonic Systems and Technologies conference Hutchison stated Skylon's development will likely end up costing a total of about $15 billion.

So...to an accountant a $2.7B change in a period of 2 years (2009 REL estimate vs. 2011 statement) would represent what we call a "material change".

I would like to see Skylon, but the development cost estimates concern me.  I would like to go through the full economic case presented by REL in RD2, but I was unable to find it on the net.

Please do not misinterpret my post, I do think that Skylon should be developed.  I believe the future of human/orbit interface is with a vehicle which is partially air breathing and can take off using conventional runways.  I also believe Skylon would be ideal for an orbital recapture vehicle.  The issue I take is with the suggestion that Skylon can be financed commercially and should be used to deliver 10-15mt payloads to LEO.  From what I have seen that niche will probably be filled by conventional rockets until we develop LEO capable linear accelerators.

[93143]

On page 18 of the ESA's SKYLON Assessment Report

"Finally REL presented an analysis of operator economics, again with a pessimistic view of trying to capture the existing market without looking at the new and expanded markets that this vehicle could establish. They showed that the estimated operating costs for 70 flights per year could be as low as $9.47M per flight (Jan 2009 prices)."

That could mean total fixed+amortized+incremental cost for the flight.  At the very least it must include fixed costs of some sort somewhere, especially given that it includes a flight rate as context.

Also, your number for amortized development cost seems to be wrong for the case you tried to analyze.  For 30 vehicles, the number is much lower - on page 20 the report states $810M per vehicle (or $4.05M per flight) using the UK's official discount rate of 3.5%.

Assuming your figure for manufacturing cost is accurate, and that the $2M figure I remember seeing is the actual incremental operating cost, we get $4.05M+$2.25M+$2M = $8.3M, leaving $1.17M per flight for the flight-rate-insensitive portion of the total infrastructure and labour costs.  (I know that's an overly simple model, but it'll do for now.)

Even if the operations portion really is $9.47M, that's still $15.77M total, or $1051/kg.  Keep in mind that this is an unsubsidized price, which basically makes it unique in the world.  IIRC, Arianespace would still be deep in the red if they'd had to shell out for development...

I may have misunderstood the 2011 written evidence and the $1.00/mt may be based on 30 craft flying 70 missions total per year.  The issue there is that each SKYLON would only be required to fly 2-3 missions per year in which case a 48 hour turnaround time would not be a consideration.

They may be looking ahead to a much higher activity level.  They're hoping to grow the launch market massively; a system like this makes that much easier to do.  I seem to recall a chart around here somewhere that illustrated the onset of market elasticity at about $1000/kg...  or was it $1000/lb?

So...to an accountant a $2.7B change in a period of 2 years (2009 REL estimate vs. 2011 statement) would represent what we call a "material change".

ESA recommends that the development cost model of the vehicle be re-assessed to account for the additional cost of developing the SUS.

Hmm...

The issue I take is with the suggestion that Skylon can be financed commercially and should be used to deliver 10-15mt payloads to LEO. From what I have seen that niche will probably be filled by conventional rockets until we develop LEO capable linear accelerators.

I hope you aren't talking about gun launchers.  Anything that releases its payload while still in the atmosphere has far too many disadvantages to ever be viable, especially if it operates at a fixed inclination.  Even something like a launch loop has significant issues.

Besides, Skylon is being financed commercially.  Though LE thought government support wouldn't be out of line, due to the public good it represents...

It's not the silver bullet a working high-thrust Mach-effect device would be, and there's a nonzero risk of it being a flop, but as far as I can tell the evidence is on the side of it making economic sense.

[Space OurSoul]

Here is a consideration that I haven't seen raised for Skylon costs before, and I for one have no idea of its potential impact on Skylon launch prices. I wonder if anyone has a more quantitative notion.

Skylon, being horizontal take-off, has, at least in principle, anytime-abort. Granted that with a take-off speed of around 0.5 Mach, the abort options may be few.

So what does this do for insurance rates? These are a sizable fraction of current launch costs. Might Skylon's abort advantages lower insurance rates and therefore also contribute to lower total cost to orbit?

[alexterrell]

Low insurance costs come with a track record of launches.

But typically if you lose your mission, that's $200 million of rocket and $400 million of payload.

With Skylon, it might be $1 billion of launcher, and $200 million of payload (because cheaper launches will drive customers to cheaper payloads).

So I'd expect insurance to be a lot more, at first.

But subsequently, on launch 20, the Skylon will have flown 19 times without mishap. An Atlas on the launch pad has never ever launched before.

[lkm]

Given that there were 23 total launches of commercial LEO payloads in 2010 (per the FAA’s 2010 Commercial Space Transportation Review), and that projected growth is 8%
....
However, if we assume SKYLON came on line in 2022 (10 year gestation period) the demand for LEO payloads would only justify 40 launches in the 1st year of operation given an 8% growth rate.  Over a 10 year period, given a growth rate of 8%, a total of 554 payloads would be available for transport to LEO. 

Two thirds of the commercial launches were to GTO not LEO in 2010 which you've failed to take account of in your extrapolation. Skylon addresses GEO either through the Skylon Upper Stage or the Fluyt OTV. Every Fluyt mission takes 5.2 Skylon launches, I believe.  So if half the GEO launches are large enough to require a Fluyt then that's 1331 Skylon launches over 10 years, or an average of 133 launches a year by your numbers or nearly twice the 70 flights a year REL use as their baseline.

[flymetothemoon]

Given that there were 23 total launches of commercial LEO payloads in 2010 (per the FAA’s 2010 Commercial Space Transportation Review), and that projected growth is 8%
....
However, if we assume SKYLON came on line in 2022 (10 year gestation period) the demand for LEO payloads would only justify 40 launches in the 1st year of operation given an 8% growth rate.  Over a 10 year period, given a growth rate of 8%, a total of 554 payloads would be available for transport to LEO. 

Two thirds of the commercial launches were to GTO not LEO in 2010 which you've failed to take account of in your extrapolation. Skylon addresses GEO either through the Skylon Upper Stage or the Fluyt OTV. Every Fluyt mission takes 5.2 Skylon launches, I believe.  So if half the GEO launches are large enough to require a Fluyt then that's 1331 Skylon launches over 10 years, or an average of 133 launches a year by your numbers or nearly twice the 70 flights a year REL use as their baseline.

Moreover it has always appeared that REL have stated their cost and flight rates quite conservatively.

It also seems that there are many people almost willing there to be no market for the amount of flights multiple Skylons (or other) could achieve. On the contrary it seems that having this possiblity will open minds and markets for launch we haven't even thought of yet. If it's cheap enough, people will use it. They don't use it now cos it ain't cheap enough!

With this being true, many more Skylons might be built than their conservative baseline - and I am sure this is what REL really like to think even though they quite reasonably feel the need to present sober, considered and conservative predictions.

Of course SpaceX are claiming even lower long term figures for (a) re-usable launcher(s), but whilst that too is an amazing prospect, SpaceX seem to me much less concerned about being conservative in their presentation of the future!

Even then it seems likely that there could still be a place for an easily and quickly re-usable launch craft which can use a runway and might also potentially fly 40 people to LEO or the other side of the world.

[lkm]

Given that there were 23 total launches of commercial LEO payloads in 2010 (per the FAA’s 2010 Commercial Space Transportation Review), and that projected growth is 8%
....
However, if we assume SKYLON came on line in 2022 (10 year gestation period) the demand for LEO payloads would only justify 40 launches in the 1st year of operation given an 8% growth rate.  Over a 10 year period, given a growth rate of 8%, a total of 554 payloads would be available for transport to LEO. 

Two thirds of the commercial launches were to GTO not LEO in 2010 which you've failed to take account of in your extrapolation. Skylon addresses GEO either through the Skylon Upper Stage or the Fluyt OTV. Every Fluyt mission takes 5.2 Skylon launches, I believe.  So if half the GEO launches are large enough to require a Fluyt then that's 1331 Skylon launches over 10 years, or an average of 133 launches a year by your numbers or nearly twice the 70 flights a year REL use as their baseline.

Moreover it has always appeared that REL have stated their cost and flight rates quite conservatively.

It also seems that there are many people almost willing there to be no market for the amount of flights multiple Skylons (or other) could achieve. On the contrary it seems that having this possiblity will open minds and markets for launch we haven't even thought of yet. If it's cheap enough, people will use it. They don't use it now cos it ain't cheap enough!

With this being true, many more Skylons might be built than their conservative baseline - and I am sure this is what REL really like to think even though they quite reasonably feel the need to present sober, considered and conservative predictions.

Of course SpaceX are claiming even lower long term figures for (a) re-usable launcher(s), but whilst that too is an amazing prospect, SpaceX seem to me much less concerned about being conservative in their presentation of the future!

Even then it seems likely that there could still be a place for an easily and quickly re-usable launch craft which can use a runway and might also potentially fly 40 people to LEO or the other side of the world.

REL have a chart in their Space Solar Power study showing $/kg against flight rate which extends out to 1 million flights a year and $80/kg while the study itself posits 10000 flights a year at $200/kg and twenty flights a day per launch site for 33.3GW of satellites. So yes, they've thought about higher flight rates.

Another possible flaw in this flight rate analysis is that it ignores governmental flights, there were 51 in 2010 and it seems perverse to assume that at least some of those government payloads post 2022 aren't going to end up on Skylon's either commercially or by  friendly nations adding a Skylon or two to their Air forces to launch national security payloads. Would the USAF really not be interested in a Skylon to provide the rapid reaction launch they claim they need?

[flymetothemoon]

REL have a chart in their Space Solar Power study showing $/kg against flight rate which extends out to 1 million flights a year and $80/kg while the study itself posits 10000 flights a year at $200/kg and twenty flights a day per launch site for 33.3GW of satellites. So yes, they've thought about higher flight rates.

Another possible flaw in this flight rate analysis is that it ignores governmental flights, there were 51 in 2010 and it seems perverse to assume that at least some of those government payloads post 2022 aren't going to end up on Skylon's either commercially or by  friendly nations adding a Skylon or two to their Air forces to launch national security payloads. Would the USAF really not be interested in a Skylon to provide the rapid reaction launch they claim they need?

I am aware of the Space Solar Power analysis. Just one example of how the flight rate could change in a way unimaginable once people really contemplate the possiblities of affordable launch.

Indeed. It's not just commercial that may see the possibilities.