[AR] Re: Ozone layer was Re: Removing Coking Deposits
- From: Peter Fairbrother <zenadsl6186@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Tue, 20 Sep 2016 16:00:48 +0100
On 20/09/16 04:39, Henry Spencer wrote:
On Tue, 20 Sep 2016, Peter Fairbrother wrote:
I like wings wheels and jets for the first stage, but if you prefer a
SpaceX/Blue Origin style vertical landing that's OK. WWJ gets you back
in the air much quicker though.
That last is an assumption, not a self-evident fact. Nobody's yet built
a VTVL rocket that can do really fast turnaround, but then, nobody's yet
built a 100km Mach 6 airplane that can do that either.
Yes - however there are reasons to think a WWJ (with pilots) would have
a faster turnaround.
First of all, weather - it does seem evident that a WWJ can operate in
higher winds than a VTVL.
Second, landing site vs takeoff site. A WWJ can takeoff, fly backtrack
on jets before turning forward for main boost phase, and then glide to
land at the same site where it took off from - avoiding the transport
problems and time involved in landing several hundred miles away from
its takeoff point. I don't think a VTVL can do that.
Even if that was not possible, I don't think a VTVL can be refuelled,
recargoed, and take off from the spot where it landed. Might be wrong.
But I'm pretty sure a WWJ can taxi to the refuelling/recargoing point.
Plus, if you want to move WWJs round on the earth for operational,
maintenance etc reasons, then you just fly them wherever you want them.
VTVLs would need a transporter.
All too
plausibly, it could end up being less like a 747 and more like a B-58
(the plane whose operating costs were too high, and dispatch reliability
too low, for even the USAF).
I'd expect the first version to be more like Concord - technologically
it works, but it isn't optimum.
But supersonic flight in large aircraft is fundamentally not the same as
space launch; acceptable alternatives to supersonic flight in large
aircraft include subsonic flight (as happened with the Hustler being
taken over by the B-52), whereas for a WWJ/VTVL the alternatives are a
different space launch system, or not going.
There ain't no cheap way to do it.
Plus, WWJ becomes economic at much less than a million flights per year.
Probably a little higher than VTVL, but still much less than a million
flights per year.
"This *isn't* just like an airplane." --
Jeff Greason.
No, but a WWJ is a lot more like an airplane, with the millions of
man-tears experience of building and operating airplanes, than a VTVL is.
-- Peter Fairbrother
A note on the Hustler - I heard that the reported 3x the cost of the
B-52 high operating costs were calculated to include in-flight
refuelling - without which flight costs per hour were only about 30%
higher than the B-52, If they had been based closer to target, the
operating costs would be much less than the reported 3x the cost of the
B-52.
I conjecture that at high speed, without refuelling, flight costs per
mile may have actually been less than the B-52, though I don't know
whether that is true or not.
But the SA-2 killed the B-58, without firing a single shot at it.
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