Quote from: john smith 19Quote from: high roaddedicated landing strips, Wrong again. A dedicated launch runway to orbit, but in air breathing only mode Skylon can take off from a much wider range of runways. Most of the length is to meet emergency stop criteria for the fully loaded vehicle, which only apply when it's fully loaded to go to orbit. Landing is much easier with a low empty weight and no engine noise issues. That's what I said. The Skylon needs a dedicated runway to get to orbit. Using the SABRE engine for an airplane doesn't require the Skylon design.
Quote from: high roaddedicated landing strips, Wrong again. A dedicated launch runway to orbit, but in air breathing only mode Skylon can take off from a much wider range of runways. Most of the length is to meet emergency stop criteria for the fully loaded vehicle, which only apply when it's fully loaded to go to orbit. Landing is much easier with a low empty weight and no engine noise issues.
dedicated landing strips,
For take off for inter-airport/spaceport there might be some questions about the hot exhaust from the SABRE engines.
However because the vehicle would be much lighter I think the expectation is that the engines would not be on full thrust, so the exhaust would not cause damage. Again this is not expected to be a common occurrence, just in the event that the Skylon cannot reach home base for some reason.
Also, even if you meant dedicated orbital launch runway, can you really count that against Skylon? It's not like I can launch an orbital rocket from any old local runway either.
Without fuel Skylon will be light enough to be towed by another aircraft. As an alternative to self-ferry it has advantages (mainly saving on engine wear and tear). So that's another option if Skylon lands at a standard airstrip and needs to be transported back to the launch site.I'm not sure what type of towing aircraft would be required, and it remains to be seen how practical this would be. It'd be a pretty impressive sight given the size of the spaceplane. The largest glider ever built was the Me 321 Gigant, and that was 'only' 28m long, compared to Skylon's proposed 83m length.
I seriously doubt this could be possible. Not because of Skylon weight, but because of take off speed and necessary rotation angle.
He stated they expect to have the engine running by 2019, he also showed what appeared to be a single engine test flight model similar to the BAE Systems recent video.
When asked what the single engine flight vehicle will cost to build and fly he said around 1 billion, when asked where the money is for this, he just shrugged his shoulders !!
Finance has always been the issue with SABRESkylon. I believe the key is to find a way to turn customer interest into a binding "pre-agreement," with no money up front but an absolute commitment to purchase at a set price (adjusted to track inflation) if the finished product meets certain stated criteria. The results of these negotiations would have to be in a form that can be transferred to the consortium that will make the Skylons to fulfill With a batch of these in the bank REL would be in a much stronger position to encourage the formation of such a consortium and the consortium would be in a much stronger position to raise finance, since in principle they have already been sold. The nearest thing I'm aware of to this is in large construction projects, where sub contractors are "novated" from the design team to construction team, but it would be quite a tricky piece of both international contract law and finance to make work.
As I see it, the issue with SABRE/Skylon is that they have yet to demonstrate their technology works. Perhaps one day they will.. but until then no-one should be surprised by the lack of commercial interest.
Quote from: CameronD on 08/04/2016 04:57 amAs I see it, the issue with SABRE/Skylon is that they have yet to demonstrate their technology works. Perhaps one day they will.. but until then no-one should be surprised by the lack of commercial interest.REL have demonstrated quite a bit of the technology works at the bench top level - the pre cooler, inlets, the nozzles under both cold and hot flow conditions.
That's nice... so when will they be testing a complete engine??
(Note: I'm not even asking for a real, flying Skylon, noooo that would be too much. Nor even a fully-functioning flight article.. no, how's about a single test engine strapped to a single test aircraft? Is that too much to ask?? )
Quote(Note: I'm not even asking for a real, flying Skylon, noooo that would be too much. Nor even a fully-functioning flight article.. no, how's about a single test engine strapped to a single test aircraft? Is that too much to ask?? )I'll guarantee it'll be before anyone builds anything with a SCramjet that does anything useful beyond demonstrate you can build an SCramjet whose thrust exceeds its drag.
Quote from: john smith 19 on 08/04/2016 08:45 amQuote(Note: I'm not even asking for a real, flying Skylon, noooo that would be too much. Nor even a fully-functioning flight article.. no, how's about a single test engine strapped to a single test aircraft? Is that too much to ask?? )I'll guarantee it'll be before anyone builds anything with a SCramjet that does anything useful beyond demonstrate you can build an SCramjet whose thrust exceeds its drag. You're damning Skylon/SABRE with faint praise.
Finance has always been the issue with SABRESkylon. I believe the key is to find a way to turn customer interest into a binding "pre-agreement," with no money up front but an absolute commitment to purchase at a set price (adjusted to track inflation) if the finished product meets certain stated criteria. The results of these negotiations would have to be in a form that can be transferred to the consortium that will make the Skylons to fulfill With a batch of these in the bank REL would be in a much stronger position to encourage the formation of such a consortium and the consortium would be in a much stronger position to raise finance, since in principle they have already been sold.