Backstage - OOC Forums
General Discussion => The Speakeasy: OOG/Off-topic Discussion => Topic started by: Nmaro Makari on 09 Apr 2014, 22:25
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The Skylon: How to fly an aircraft into space - Truthloader http://www.youtube.com/watch?v=rz2UE7pZMeE (http://www.youtube.com/watch?v=rz2UE7pZMeE)
Been watching this for a while, less news about it nowadays, but still interesting.
According to the initial project brief, Skylon could reduce the cost per kilogram of moving things into space (specifically low-earth orbit) by a magnitude of about 23.
It's also been funded by the UK Space Agency and the European Space Agency.
DO WANT
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a magnitude of about 23.
Which means going from ~$23,000/kg to $1000/kg, "holy grail" territory.
I am not sure if there are any remaining material science hurdles. It may simply be at the point that finding the money to build the vehicles is the obstacle. Selling space is hard, especially if you are attempting something "unproven" with an as of yet non-existent market, which only appears when launch prices drop. Damn chicken-egg problem!
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While it will certainly bring down the technical costs of getting stuff to orbit, I am rather hesitant to say that it will move the costs-per-ton into "holy grail" territory. I'm quite sure that the costs will catch up in other sectors (especially insurance, should flights occur rather more often), but I guess I'm rather cynical about "wonder technologies".
Still, very cool (they don't go into the exact way the cooling system works in that video, but it's rather simple genius in concept) and I'll be deeply looking forward to seeing this thing fly.
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I am personally optimistic about the use of the SABRE (or a SABRE-like) rocket engine in the development of a single stage to orbit launch platform. We can be relatively sure that the first SSTO will almost certainly utilize a system that uses the atmosphere as reaction mass in the beginning of its ascent. However, for the foreseeable future, the only technology with the capabilities to really expand our space activities is conventional rocketry. An SSTO plane/shuttle is all well and good for regular maintenance of and ferrying of people/supplies to a space station or satellite in Earth orbit but the only way to mount missions beyond the small probe and manned low Earth orbit stuff we've been doing since Apollo still calls for heavy lift vehicles to put the majority of a ship or station's mass into space (minus the option of slow orbital assembly over years or decades in the fashion of the ISS which, while a technological and in some ways cultural/diplomatic marvel, is not exactly the impressive manifestation of our potential as, say, Apollo or the earlier manned missions of the US and USSR).
Two cents deposited.
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While it will certainly bring down the technical costs of getting stuff to orbit, I am rather hesitant to say that it will move the costs-per-ton into "holy grail" territory. I'm quite sure that the costs will catch up in other sectors (especially insurance, should flights occur rather more often), but I guess I'm rather cynical about "wonder technologies".
I am not sure where the 1/23 the cost comes from, but I am guessing it is targeting the $1,000/kg. NASA (http://www.nasa.gov/centers/marshall/news/background/facts/astp.html_prt.htm) puts today's cost at $10,000/lbs or $22,000/kg.
I doubt it is comparing itself to SpaceX's Falcon 9 (http://www.spacex.com/falcon9) or Falcon Heavy (http://www.spacex.com/falcon-heavy). The as-of-yet unflown Falcon Heavy is targeting 53 tons to LEO at a top-end cost of $135M - so <$2550/kg.
I need to research the insurance more, but I know that the US government ends up paying 50% more (http://spacenews.com/article/launch-report/40006spacex-says-requirements-not-markup-make-government-missions-more-costly) to "self-insure." Given a lower launch costs and more frequent launches, my expectation is that launch insurance would come down. Right now, the history is just not there (outside the Russian vehicles) to build a statistical profile.
However, for the foreseeable future, the only technology with the capabilities to really expand our space activities is conventional rocketry. ... the only way to mount missions beyond the small probe and manned low Earth orbit stuff we've been doing since Apollo still calls for heavy lift vehicles to put the majority of a ship or station's mass into space (minus the option of slow orbital assembly over years or decades in the fashion of the ISS which, while a technological and in some ways cultural/diplomatic marvel, is not exactly the impressive manifestation of our potential as, say, Apollo or the earlier manned missions of the US and USSR).
Except that other than Apollo-Saturn V, Skylab-Saturn V, and Shuttle, none of the launch vehicles used to date are really in the category of heavy lift.
The slow orbital assembly (http://www.russianspaceweb.com/iss_chronology.html) of the ISS was a function of launch vehicle losses, budget issues (and cancellations), and the very real limits on the time between relaunching a Space Shuttle. Prior to the Challenger Accident, the fastest turnaround was 54 days (http://en.wikipedia.org/wiki/STS-61-B). Post-Challenger Accident, Columbia did it in 88 days (http://en.wikipedia.org/wiki/Criticism_of_the_Space_Shuttle_program#Shuttle_operations). Post-Columbia with even more scrutiny and 16 missions to complete between 3 Shuttles any hope of turning an orbiter in 3 months seems down-right unreal. Six to nine months seems to have been the norm.
Fundamental, the hardware for launching something to space, whether it is expendable or fully-reusable, is not the true cost driver. The true cost driver of any launch system today is the standing-army of technicians and engineers that design, build, and maintain the systems. The only way to drive down the cost to launch is to spread out the cost of the standing-army across more launches.
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Proposition for the more technically minded among us; If this sort of tech plays out and it is faster and cheaper to move goods and materials into space as promised, does this then raise the realistic prospect of being able to construct a truly space-going vehicle in Earth's orbit? I.e. construct a vehicle that does not need to escape Earth's gravity in such a way as a ground launched rocket?
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The possibility to construct/assemble a space-only vessel is a realistic possibility with or without a RSSTO.
NASA presented the Nautilus-X (http://en.wikipedia.org/wiki/Nautilus-X) concept in 2011. Sadly it has not gained traction.
(http://upload.wikimedia.org/wikipedia/commons/7/7d/Nautilus-X_Global-view-1.png)
A RSSTO has the potential to increase the launch rate and therefore reduce the launch costs by at least an order of magnitude, especially if it lands and takes-off like an airplane.
Even just a reusable first stage has the potential to reduce costs. We may get to see how close we are to achieving that on Monday (http://spaceflightnow.com/falcon9/009/status.html), if not delayed by issues elsewhere (http://spaceflightnow.com/station/exp39/140411mdm/#.U0lwtPldWKI). But again this is tied to an increased flight rate.
There is a vitreous cycle that develops.
10 As launch cost comes down, more people can utilize the service.
20 As more people utilize the service, launch rate increases.
30 As flight rate increases, fixed costs (manpower, infrastructure) are spread out across more launches reducing the cost of an individual launch.
40 Goto 10
At least that is the current theory.
In the spoiler is a simplified discussion of civil aviation costs to act as a point of comparison.
[spoiler]We can almost barrow directly from the civil aviation world. A Boeing 737-900ER (http://en.wikipedia.org/wiki/Boeing_737) costs $89.6M. It carries 6,875 US gal of jet fuel, for rough order of magnitude use $6/gal, or $41,250. It can hold 177 passengers in a "typical" configuration.
1 flight ever, the cost of the airplane clearly dominates. The price for a single passenger is over $500k!
50 flights/year for 5 years, the cost of the airplane/flight is ~$2025/passenger with another ~$233/passenger for fuel. The aircraft is still dominating!
Non-stop from LAX to DFW (two hubs) costs ~$350/passenger. This means that assuming only $50/passenger has to go into the operations cost of the flight (the people). A single airplane has to fly 7,562 times before it is paid off! (using the numbers previously given). This is 4 to 5 flights per day if it has to be paid off in 5 years. Over 10 years, 2 to 3 flights per day.[/spoiler]
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https://www.youtube.com/watch?v=_pDz0p75yg8 (https://www.youtube.com/watch?v=_pDz0p75yg8)
More information about the practical application vis-a-vis the ISS.