Demo video of the Axel tethered rover - we could have used this to rappel down Victoria!
Axel Rover

More info here.

And here

And here.

This remembers me of one of the old designs for the 1960s Prospector lunar rover

This is mind-blowing.
The winch in the middle is exactly what I need to install in the 'abdomen' of my spelunking spider, SHELOB, to explore Martian caves. The main difference is that my cable will have a fiber-optic core to transmit instructions, data, and video between the surface base station and the subterranean (sorry, don't know the Mars term) probe. I still prefer the six or eight legged spider design to provide long legs for climbing up over bouldery rubble obstructions, and to provide a spacious, stable platform for cameras and other sensors, laser spectrometer, sampling 'mandible', and an exobiology-lab-in-a-shoebox.
But, hey, these guys and I are all on the same page. Bliss.

It looks like some sort of Framsticks creature.

Major flashback time. I made one of these nearly forty years ago. From a Ladybird book using (as per the link) a wooden cotton reel, pencil, rubber band and a chunk of wax.

Andy, momentarily back in 1970.

. . and Nigel likewise a few years earlier. I used to make big ones out of cable reels.

A wacky question comes to mind. Could mechanical energy storage using elastic or springs (I'm guessing flywheels would be too heavy) have any extra-terrestrial robotic applications?

As I said on Twitter - A Mississippi Steam Boat captain just called. He wants his paddle wheels back.

I love that the project page at CalTech lets you see the guts!

Shaka - speaking of "same page" - I assume you have seen these critters?

Yeah! LEMUR! Other-side-of-the-pillow cool. Del Palmer put me onto it back in the original cave explorer thread.
Definitely a step in the right direction! I hope work is continuing to make it a really agile rock climber.