By toothbrush to the stars! Answered
A concept known as a space elevator has been "doing the rounds" as a cheap way into orbital space for several decades now.
Basically, a cable of some description is anchored to an orbiting mass, and vehicles climb up and down the cable to transport materials and passengers to and from orbital space cheaply and easily (in any space journey, the most expensive and dangerous parts of the journey are the first and last few kilometres).
There are, technologically speaking, two main hurdles - the cable, and the vehicles.
Carbon nanotube composites are a strong contender for the cable, but travelling up and down the cable takes power. Rockets are out of the question (what would be the point of the cable?). The hours, possibly days, of the journey make batteries unfeasible, and the turbulence of the atmosphere precludes the use of PV panels large enough to power the vehicles from daylight.
That leaves transmitted power.
So far, the transmission ideas have been electromagnetic - lasers aimed at smaller PV panels on the underside of the vehicles, or microwaves aimed at receiver dishes.
Now, a new proposal suggests transmitting the energy mechanically.
European Space Agency ground station engineer Dr Riise ... proposed sending power mechanically - effectively by providing a carefully timed jerk of the cable at its base.
To demonstrate, he employed a broomstick to represent the cable held in tension, and an electric sander to provide a rhythmic vibration to the bottom of the stick.
Around the broomstick's circumference he tied three brushes representing the climber with their bristles pointing downwards - meaning it took slightly more force to lower the brush assembly than to raise it.
The vibration from the sander allowed the assembly to slide upward along the broomstick as it moved slightly downward, but grip it as it moved slightly upward. The net effect: the assembly rose against gravity straight to the top of the stick.
That's a bristlebot (or vibrobot)! Dr Riise, though, calls it a longitudinal wave climber or LWC.
It sounds easy enough to replicate the demonstration model, although I can't imagine how you would efficiently vibrate a 36,000km cable (I have images of damaging harmonics getting set up as the moving carriages change the effective length of the vibrating part of the cable, and shaking important bits off the vehicles).
Apparently, though, the idea is being looked at by lift manufacturers for installation in the next generation of super skyscrapers.