Talk of crash scenarios applies just as well to regular airliners, which SKYLON plans to be certified as, so anyone with that kind of imagination should live somewhere that airliners don't overfly or take medication for their nervous condition.
Quote from: baldusi on 10/29/2012 03:50 pmIt's a robotic aircraft with a ridiculously high GTOW percentage of which is liquid H2. High certainly. I think you'll find it's no worse than the plane Steve Fosset was flying on his solo round the world flight. QuoteIn fact, since it uses O2 from the atmosphere when in plane mode, the amount of H2 is huge. Please remember that it's as or more heavy than an A380. Starting its takeoff roll yes. A chunk of that will go during the takeoff and climb out. Technically you could say that *all* of Skylons flight plan (it's an aircraft, not a missile) will be climb out (to orbit )as a robot a 45 deg takeoff slope is possible so 60kft downrange Skylon would be above *all* FAA jurisdiction. So if your runway is >12 statute miles from your countries border that would normally put it above most countries civil aviation oversight authority.
It's a robotic aircraft with a ridiculously high GTOW percentage of which is liquid H2.
In fact, since it uses O2 from the atmosphere when in plane mode, the amount of H2 is huge. Please remember that it's as or more heavy than an A380.
SKYLON ascent trajectory:
Quote from: BobCarver on 10/30/2012 11:55 amSKYLON ascent trajectory:Nice graph. I used 45deg because 1 unit of length gives 1 unit of altitude rise and I was being lazy.IIRC normal climb angle for airliners is about 7 deg (felt a hell of a lot more out of Newark. Like a roller coaster )That's roughly 1 in 8 climb out so you'd need to be about 147Km from the border in your launch direction to be above the 60k ft level and outside controlled airspace (at least if you were flying over the US. I'm *guessing* most other countries rules are pretty similar). By that point it would be a mostly *empty* flying propellant tank, giving the same sort of explosion hazard as *any* other large aircraft.
But, if you ran cargo or passenger SKYLON flights to a resort hotel in a polar, sun-synchronous orbit (which has advantages from the point of view of visitors always having a view of the Earth lit up in daylight), a launch site nearer the poles wouldn't be unreasonable as there would be no advantage to an equatorial spaceport for such a mission.
With the vehicle stationary the engines are ignited in air-breathing mode, burning hydrogen fuel with pre-cooled compressed air. When nominal performance has been verified the brakes are released and the vehicle begins its take-off roll. The vehicle takes off from the runway in the same manner as a high performance jet aircraft with a take-off speed close to Mach 0.5. Following takeoff the vehicle jettisons around 3 tonnes of water, which would have been required by the boiling water braking system for a rejected take-off, should a malfunction have occurred.After take-off the vehicle climbs and accelerates on its predetermined trajectory for 694 seconds (approx 11 1⁄2 minutes), by which time it has reached an altitude of 28.5 km and a speed of Mach 5.2. The vehicle is now 620 km downrange from the launch site.
One thing, if you're starting from 5 km up already, the drag you're going to experience as you accelerate to supersonic speeds is going to be significantly less.
But, if you ran cargo or passenger SKYLON flights to a resort hotel in a polar, sun-synchronous orbit (which has advantages from the point of view of visitors always having a view of the Earth lit up in daylight)
Quote from: BobCarver on 10/30/2012 05:51 pmBut, if you ran cargo or passenger SKYLON flights to a resort hotel in a polar, sun-synchronous orbit (which has advantages from the point of view of visitors always having a view of the Earth lit up in daylight)Night views from ISS seem spectacular. Would be disappointing to go to orbit and not see that.cheers, Martin
Higher radiation exposure in a polar orbit.
Thanks for the chart. I'm afraid we've wandered off-topic here. But, we have to deal with radiation if we're ever going to leave LEO.