On: Japan's zero-gravity space drone sends first pictu...

[averagewall]

The brake is an internal force though (the force and its reaction both act on the bicycle). The whole unit's only external forces are from the fans so that's all it can use to translate. That and bumping into things.

[TeMPOraL → averagewall]

> That and bumping into things.

Come to think of it - in air you're constantly bumping into things - air molecules. I think it could technically be possible to steer in zero-g within an atmosphere by pure rotation (e.g. consider that a fast-spinning object is kind of a (crappy) fan).

[LeifCarrotson → TeMPOraL]

And, in fact, that's what this device does.

It uses an array of 12 small rotating fans placed around its surface to push jets of air and move itself from place to place.

[DonHopkins → LeifCarrotson]

Can it face you with one of its fans and run it at the same high speed as the opposite fan, to keep you cool, and take photos of you with your hair blowing in the wind?

[TeMPOraL → LeifCarrotson]

Yes, I know.

My point was that in principle, you could abuse reaction wheels to give you translation capability if you're moving through air.