Keith is building up to explaining his Lofstrom Launch Loop (not a space elevator), a science fiction idea that could drive some interesting techie toons.He's doing a good job of discussing the work involved in achieving orbit with traditional rockets, like that vertical stretch of a space shuttle's venture is but a preamble, after which she turns 90 degrees and continues accelerating like crazy to reach orbital speed... Instructive slides.
Those ill-fated fuel tanks with O-rings wouldn't have needed O-rings if they hadn't been built in sections in order to fit through Rocky Mountain train tunnels, given where Congress insisted on building them. Didn't know that before.
He calls our Spaceship Earth "the first space colony" which seems a good way of looking at it, although "colony" implies we're really aliens in disguise. We do a good job of fooling ourselves in that case.
Rocket science is pretty difficult by the way, as fuel makes things heavy, requiring more fuel, which gets spent, lightening the load. So how much do you need?
Keith speculates Earth may lose its Moon at some point, given how angular momentum keeps transferring to it, rotation here slowing. Dick Pugh is in the audience, corroborating some of the astronomy. David Feinstein is asking good questions.
The launch loop uses magnetic induction to push solid iron at high enough speeds (about 14 km / sec) to dynamically support a giant monorail that soars 80 km out into space, follows the curvature of the earth, and comes back in, with turnarounds of 15 km radius (hence "loop").
Payloads get strapped on maglev sleds at West Station, at the end of a 10% deflection, with different models for freight or people. These small truck sized sleds, likely rocket equipped to fine tune the orbit, accelerate with up to 3 gees of force along the monorail, achieving orbital velocities. They do this by loosely coupling with the monorail's induction field in some way, lots of experiments still needed.
The return rail runs parallel, lasers pointing between them, tracking distances with high precision. This feedback, along with information from other sensors, goes to the controlling electronics required to keep the loop stable (various differential equations apply).
That's a whopping 130,000 tons of force needing to be deflected around each of the underwater turnarounds.
The sheathed acceleration track is quite small in diameter (mere centimeters), is strapped to floats in the ocean along the equator.
Keith says we've had suitable materials since the 1970s (e.g. Xylon for anchor straps), although the choices are even better today.
People might experiment with this to get more satellites doing low power cellular, plus there are sports opportunities. He's got some numbers for the bean counters to crunch on. Screenwriters?
