Skylon ‘spaceplane economics stack up’

http://www.bbc.co.uk/news/science-environment-27591432

by timthorn • 12 years ago

75 52 12 years ago

bbc.co.uk

iwwr• 12 years ago

So is it just a suborbital plane that can launch something high enough where an additional small booster can put the payload in orbit?

filipncs• 12 years ago

No, it's single stage to orbit; it's a poorly written article. It goes to mach 5.4 with atmospheric air before switching to liquid oxygen. The article makes it sound like it only ever reaches mach 5.4.

http://en.wikipedia.org/wiki/Skylon_(spacecraft)

trhway• 12 years ago

it is lost on me why Skylon would be noticeably better than a Mach 5-6 plane boosting a second stage. Such 2 stage system would have obviously less trade-offs and thus would be easier/cheaper to design and build.

blueskin_3• 12 years ago

it's a poorly written article.

It's the BBC, so I'd say it's an averagely written article in their context.

Someone• 12 years ago

No. It's a plane that can go into low orbit. You need an additional booster to bring stuff into high orbits. For smaller satellites, this study concludes that it is economical to recover that booster.

"power units that work like jet engines at low altitudes and slow speeds, but then transition to full rocket mode at high altitudes"

and

"Skylon itself is designed only to go a few hundred km above the Earth, so it would need an additional "upper-stage" module to push the satellite into its final, 36,000km-high orbit."

panduwana• 12 years ago

So it needs taxpayer subsidy just to be on par with fully-private Falcon 9? Seems like it loses before the match even begins.

noir_lord• 12 years ago

What a narrow world view.

A fully reusable single stage to orbit "plane" completely changes the dynamics of putting stuff in orbit both on cost and turn around time.

The Falcon 9 is privately funded as is the Merlin engine it uses however pretty much all the materials science, initial engineering etc required to design and build a merlin was publicly funded.

There are times when a public/private partnership makes sense and this is one of them.

outworlder3• 12 years ago

The 'subsidy' is less than a non-SpaceX launch would cost and peanuts for a R&D project, specially one with this potential. And it's about the same amount the US military is currently spending to certify SpaceX for military launches. What about the NASA contracts? These are done with taxpayer money too.

Fuxy• 12 years ago

I find it fascinating that Elon Musk hasn't chipped in since even though it's a competitor to SpaceX it is ultimately a step in the right direction for his goal of putting people on Mars and into space.

Hell he could take the engine and build a new spacecraft based on it.

leoedin• 12 years ago

SpaceX received a subsidy from Elon Musk. The financial case for the company wasn't clear at the start - it was only because they had significant financial backing for the initial development period that they could get to where they are now. They may now be profitable, but if you'd tried to make a case a decade ago for funding you'd get nowhere. There are all sorts of high-capital technology developments that simply aren't immediately profitable or low risk enough for VC funding. Why should we as a society rely on the whims of a few wealthy people? This kind of technology, should it be realised, has a value to everyone.

maxerickson2• 12 years ago

Why not call it a risky investment? He ended up with a big ownership stake, he wasn't just supporting them for the hell of it.

avz• 12 years ago

I'm baffled. How does the need for public financing make a project "loose before the match even beings"? The project needs public financing because private investors wouldn't shoulder the risk.

Most significant leaps of technological innovation in the history of civilization required public support. And as we move on the leaps will become harder and riskier still which means even less willingness of the private investors to put up the money. So brace yourself :P

blueskin_3• 12 years ago

They are completely different designs, with different technology and applications. The Falcon is 1940s technology updated; the Skylon is new; there has never been anything else flown using the same engine concept before.

outworlder3• 12 years ago

Forget about 'spaceplane economics'. Just get the SABRE engine out of the door already, then people can start talking about economics. Apparently the engine design has been complete for years and they just need additional funding.

Should a production SABRE engine prove to be low maintenance enough, it won't just be a matter of "stacking up", this will be huge. However, if the maintenance is costly, then it's the Space Shuttle all over again. In contrast to the shuttle, tho, there's no costly thermal protection system, the skin and some water cooling should be enough. Also, no astronauts, Skylon is supposed to be fully automated.

A fully reusable spaceplane for small payloads and a big dumb booster (SpaceX) should complement each other very well.

JulianMorrison2• 12 years ago

Skylon isn't only for small payloads. It's closer to "Thunderbird Two" in the size of payload pods.

outworlder3• 12 years ago

I stand corrected. Wikipedia says 15000kg (doesn't say at what altitude however).

mrfusion3• 12 years ago

Why wouldn't it need a costly thermal protection system?

JulianMorrison2• 12 years ago

"Because it will use a low-density fuel, liquid hydrogen, a great volume is needed to contain enough energy to reach orbit. The propellant is intended to be kept at low pressure to minimise stress; a vehicle that is both large and light has an advantage during atmospheric reentry compared to other vehicles due to a low ballistic coefficient.[44] Because of the low ballistic coefficient, Skylon would be slowed at higher altitudes where the air is thinner. As a result, the skin of the vehicle would only reach 1,100 Kelvin (K).[45] In contrast, the smaller Space Shuttle was heated to 2,000 K on its leading edge, and so employed an extremely heat-resistant but fragile silica thermal protection system. The Skylon design does not require such a system, instead opting for using a far thinner yet durable reinforced ceramic skin.[2] However, due to turbulent flow around the wings during re-entry, some parts of Skylon would need to be actively cooled.[42]"

-- Wikipedia http://en.wikipedia.org/wiki/Skylon_(spacecraft)#Fuselage_an...

ris3• 12 years ago

Who or what would use these "production SABRE engines" without a spaceplane to use it on?

twic2• 12 years ago

Maybe someone could have another go at this:

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

More seriously, there is a proposal to use a version of SABRE called SCIMITAR to power an airliner, which could be a more accessible testbed:

http://en.wikipedia.org/wiki/Reaction_Engines_A2

drzaiusapelord• 12 years ago

X-37 unmanned spaceplane exists now without any fancy SABRE engines:

http://en.wikipedia.org/wiki/Boeing_X-37

The last one was sent up on Decemember 2012 and its still up there. Probably not as cost-efficient, but, there is an unmanned spaceplane in production, but its a secretive DoD project so we don't know too many details nor will it be used for non-military applications.

simonh• 12 years ago

X-37 is launched on a traditional expendable rocket and only glides to a landing. SABRE is an air-breathing SSTO spaceplane that takes off from a runway. They're completely different beasts.

kashkhan• 12 years ago

The technical risk has to be factored in. Nobody has ever done such heat exchangers and how to keep them free of ice is a secret sauce they are not sharing. Without peer review or open discussion the engine might as well not exist.

mrfusion3• 12 years ago

They should consider a kickstarter for funding. Does anyone know if they've considered it?

rayiner2• 12 years ago

You need real money to develop aerospace technology. The SABRE engine is in its final stage of development, and according to the articles linked from the main article, just finishing the final stage will cost about 200 million pounds ($330 million dollars). That's about thirty times what the largest project in Kickstarter history has ever raised.

The article pegs the total development cost of the plane at the cost of developing an Airbus plane. That's about $10-15 billion, or more than an order of magnitude more than all of the money that has ever been raised in Kickstarter history. Probably more than all the money that has ever been raised by crowd funding period.

mrfusion3• 12 years ago

Wow, I had no idea it was that much.

Sorry for the naive question, but any ideas on why it costs so much? Wouldn't putting 100-200 top engineers on it for a few years be enough? What do they need 300 million for?

al2o3cr• 12 years ago

BRB, building one in Kerbal Space Program. :)

twic2• 12 years ago

You Must Construct Additional Skylons!

pjc502• 12 years ago

Spaceplanes are ludicrously hard to get right in KSP. The aerodynamics model is not very good and the process whereby fuel is taken from the frontmost tank first tends to make the plane flip halfway through the ascent.

I've occasionally considered writing something with a better aerodynamics sim in ...

gerbal• 12 years ago

There are a number of mods which add much finer control over fuel management and better aerodynamics to KSP.

Ferram Aerospace[1] adds much more realistic aerodynamics and TAC fuel balancer[2] adds a fuel balancer.

[1] http://forum.kerbalspaceprogram.com/threads/20451-0-22-Ferra...

[2] http://forum.kerbalspaceprogram.com/threads/25823-0-23-TAC-F...

JimmyM• 12 years ago

In true BBC-style: other brands of spaceplane are available. http://bristolspaceplanes.com/company/

DonHopkins• 12 years ago

I guess that's what happens when you go playing around with things you don't know anything about...

http://youtu.be/4-HOvQUL2zI?t=21m20s

https://en.wikipedia.org/wiki/Land_of_the_Lost_(1974_televis...

vilhelm_s• 12 years ago

I'm currently reading "The Space Shuttle Decision" by T.A. Heppenheimer, which discusses the planning in the late 1960s for a reusable successor to the Saturn rockets.

One interesting thing is that they then envisioned this to happen in phases: a "type I" partially reusable vehicle (with expendable fuel tanks and maybe expendable boosters), then a type II fully-reusable rocket-propelled vehicle (probably two winged stages which both fly back), and finally a type III air-breathing vehicle (Skylon-style air liquefaction was talked about already then).

The more advanced concepts cost a lot of money to develop, but reduce the per-launch cost. So the hope was to start with a type I vehicle (the eventual Space Shuttle) to reduce launch cost and grow the market, until there are plans for so many launches that it makes sense to fund the advanced types.

In hindsight, the Space Shuttle unfortunately kind of botched the reuseablity. But with SpaceX we finally seem to be on track to having a working partially resuable launch vehicle. Maybe this will "unfreeze the future"---with a bigger launch market and commercial pressure people might be tempted to go for something like Skylon rather than more of the same in follow-up Arianes...

bbwonder• 12 years ago

You can imagine Virgin Galactic are wll positioned to accelerate this project.

They have the airframe building technology, and the commercial vision for affordable space access.

Come on Branson, bring this British invention to life!

Skylon ‘spaceplane economics stack up’

Related Stories