You need to include some thrust capability anyway, since otherwise your target would only be accessible when it crosses the plane of the Earth’s equator*. You’d only be able to send one, or at best a few, pods per year to each target.
This will help combat sea level rise from global warming. Look at those cute kids enjoying that beach that hasn’t been washed away by rising ocean levels.
ETA: It would really be some sort of warped plane, but regardless, any target would only be available during a very short launch window.
In some ways, “siphon” is a good name, since in the co-rotating frame, you’ve got a potential “hill” with its peak at geosynch height, and you’re getting matter up the uphill part of the hill by using the energy from the matter going down the downhill part. In that sense, it’s just like a siphon.
And the limited launch windows aren’t too big of a deal, since you’d still get one launch window to anywhere you’d care about each day. You’d still want course-correction rockets on your payload, of course, but they’d be orders of magnitude smaller and cheaper than what you’d need without the elevator.
The problem I see is, how do you actually transfer the earth’s rotation to the entire space elevator structure? Every payload pod being ejected from the elevator is carrying away angular momentum from the elevator. Soon the top of the elevator starts to fall behind the earth’s rotation, and bend towards the west. How do you replenish that angular momentum and keep the whole elevator straight and taut?
I think the only way is to mount thrusters along the length of the elevator. Nothing wrong with that, but at that point it’s not a siphon or centrifuge, it’s a tethered rocket-powered platform for launching payloads.
The tether is always being pulled out by centrifugal force. If you’re constantly launching, there will be some steady-state amount of deflection, but it’s not going to fall over.
If your payload doesn’t have thrust, and you’re just relying on initial accuracy to hit a target like Mars, you’re going to only have one window a year.
No, you’d have more than that, if your elevator is long enough. We’re used to assuming that trips to other planets must use Hohmann transfer orbits, because those are the most fuel-efficient, and with our current launch technology you need every advantage you can get. But with an efficient launcher like a space elevator, you could reach other planets at other times just by throwing harder to begin with.
How are you changing the direction out of the plane of the equator? If I want to hit Mars, I need to wait for the plane of Earth’s equator to sweep across it.