h a l f b a k e r y
Expensive, difficult, slightly dangerous, not particularly effective... I'm on a roll.
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This is an ill-conceived idea. I suggest
you skip the next four paragraphs if
you're in a hurry.
So. A problem with launching satellites
that, even if you can get them close to
orbital height, you have to turn left and
get them up to orbital velocity, which is
(for low orbit) about
18,000 mph, or
something like Mach 24. Ideally, you
need to do this without crushingly large
So. A whip works by transferring
momentum gradually from the long,
body of the whip into the small, light tip.
At ground level, the tip of a hand-
whip will allegedly reach supersonic
speeds. (Yes, I know, there are all kinds
arguments about where whip cracks
from, but the tip is certainly accelerated
hugely relative to the input motion.)
So. Get your launch vehicle up to near-
orbital altitude, and release a long
very long, or possibly extremely long)
tapering, flexible strap shortly before
apogee. The tip of the strap carries a
small thruster, and also the satellite to
launched. The thruster extends the strap
away from, and slightly downward from,
the launch vechicle, just as the main
rocket angles over at the top of its flight
and starts to point downward.
At a cunningly chosen moment, the main
rocket fires its final booster, this time
aiming downwards and parallel to the
extended strap. Soon, it passes the
tethered satellite, leaving a loop of tether
behind it. In a twinkling of an eye, it
reaches the limit of the tether and, in the
same twinkling, the satellite-carrying
tether-tip flicks the satellite deftly
skyward [EDIT spaceward. Definitely
spaceward. Not skyward.], at a speed
many times that of
the now-descending rocket.
Don't get me wrong, I like the idea.
But I think I see ya problem right there!
||Why not ground-based ? world's most interesting trebuchet (or ballista or whatever it is)
||//sp. daftly// [FlyingToaster], if you're not
going to take this seriously, then neither
||When a whip cracks, the sonic boom is caused by the tip being *rotated* (as the radius of the inscribed circle and the weight of the stationary "tip" both approache zero) with a linear displacement of almost nothing.
||What you want to do is waaaay beyond the physical strengths of modern materials... you want to flex and rotate something at mach24... what will happen is the end will snap off possibly leaving the payload spinning like hell, but with a forward velocity no different than the original velocity of the booster rocket.
||I still [+]'d it for the picture and for the possibility of a ground-based mach1'ish trebuchet spinoff.
||(when I was a kid I practised for weeks and weeks with a 30' dogteam whip and only got it to crack a couple times when nobody else was around...)
||Hmm. Welllllll, I'm not so sure. The basic
idea is that the tip gains in velocity relative
to the motion of the handle. Now, I'd
imagine that the accelerations would be
dependent on the geometry of the
situation. So, with a big enough whip, you
might be able to get (say) a 20:1 ratio of
velocities without any unfeasible peak
||I had a nylon strap that was used to tie
down airplanes in the Air Force. I tied it
with stainless steel wire to the end of a
long green stick with twist pliers.
||It would make a fantastic crack.
||It once got away from me and I popped
myself full force on the back of the calf.
I had a really bad welt that didn't
disappear for about two weeks.
||I love this idea. When they get that
carbon nanofiber ribbon together, we'll
be in business.
||Why use a whip? If we roll a large enough towel up, we can toss the payload into the air, flip it in the heatshield and off it goes. I think ACME might have a giant sling shot that we can use for the initial toss.
||// I suggest you skip the next four paragraphs //
||Thanks, that really did save time ;)
||I had been toying with this idea but I didn't post it because I hadn't really thought through the aiming and delivery at the end of the whip. I see now that that isn't an issue yet.
||I'm still thinking about it.
||Mmmm, perhaps an low earth orbit bolas (boleadoras)?