Partial Space Elevator
Don't tether the Earth-facing end of space elevator: let it hang in the atmosphere, and arrive to it with less fuel.
The idea of space elevator is not new at all, but the consideration of not tethering one of its ends to Earth has not been widely discussed.
It's not new though: a paper of 2014 from Acta Astronautica has analyzed the idea of a space elevator with both of its ends hanging in space, and found that it might cut the costs of space travel to high orbit by 40 percent.
I think it's worth putting this idea down here, so that relevant projects could be linked to it in the future.
+[項目]
兩點：
我們現在就可以開始推出最輕的部分 - 尖端！繫繩所需的強度在其整個長度上並不相同 - 爲了最大限度地減輕重量，它必須向地球末端逐漸變細，並且尖端非常輕。因此，讓我們在軌道上找到一顆合適的對地靜止衛星，併爲其帶上一些膠帶（繫繩）。
已經在軌道上的太空垃圾非常適合配重結構。將垃圾送入地球靜止軌道所需的燃料比將其從地球表面升起所需的燃料要少得多。
Two points:
We can start rolling out the lightest part of it - the tip - right now! The strength required by the tether is not the same across its length - to minimize weight, it has to be tapering off towards the Earth's end, with very light tip. So, let's find a suitable geostationary sattelite in orbit already, and bring some tape (tether) to it.
Space junk that's already in orbit, is great for the counterweight construction. It requires much less fuel to lift the junk into the geostationary orbit, than to lift it up from Earth surface.