[AR] Re: Amateurs and HSF
- From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
- To: Arocket List <arocket@xxxxxxxxxxxxx>
- Date: Tue, 26 Jul 2022 16:29:36 -0400 (EDT)
On Tue, 26 Jul 2022, Peter Fairbrother wrote:
..."the thrust of which is greater than its lift for the majority of
the rocket-powered portion of its ascent". My understanding is that
this is taken to mean time...
Hmm, so could you take off then climb gently for ten minutes under lift, and
then thrust up for eight?
Maybe, given a deep-throttling engine. This definition was part of a
laboriously-negotiated treaty :-) between the airplane people and the
space-launch people, to set a clearly-defined boundary between their
jurisdictions. The exact boundary is fairly arbitrary, and it's not too
surprising if some borderline cases end up on the "wrong" side of the
boundary; details might have to be renegotiated someday if there are too
many of those.
(Real-world boundaries between nations can be messy too, if they're based
on ethnic/linguistic/religious issues rather than pure geography. In a
number of places in the world, there are little pockets of country X
entirely surrounded by country Y, near the main X-Y boundary. Worse, such
a pocket can then have a subpocket of country Y inside it. And so on! --
there are apparently a few places on the India-Pakistan boundary where the
pockets are nested five levels deep...)
Orbit here we come ... ;)
Alas :-), if it can place a vehicle or payload in "outer space" -- the
definition of which is not made clear, but will surely include any Earth
orbit -- then it's definitely a launch vehicle, not an airplane, and so is
under the spaceflight rules. The suborbital-rocket rule just resolves
borderline cases where the thing is not really in space, at least not
much.
(At least, that was the intent. When the rule was new, at one Space
Access somebody observed that it is probably possible to do a free-return
lunar flyby while remaining within the official definition of "suborbital
trajectory"...)
Henry
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