At a million a year, a vertical railgun and small horizontal kick at GEO starts
to look good...
Sent from my iPhone
On Sep 19, 2016, at 8:39 PM, Henry Spencer <hspencer@xxxxxxxxxxxxx> wrote:
On Tue, 20 Sep 2016, Peter Fairbrother wrote:
...That takes around a million flights per year. While the vehicles
don't generate a lot of ozone distorying NOx on the way up, they do
during reentry...
No-brainer solution - limit re-entry.
In practice, anybody who's ramping up to fly *anything* a million times a
year should be thinking really hard about non-rocket alternatives like space
elevators or launch loops or orbital catchers. (We still lack the structural
materials needed for a classic geostationary elevator, but there are
less-demanding alternative designs.) That's the sort of volume where it
really pays to spend more up front, building a pipeline rather than an armada
of pickup trucks. And many of the "pipeline" approaches have ways to bypass
classical aerobraking reentry.
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. 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).
"This *isn't* just like an airplane." -- Jeff Greason.
Henry
