Going by known record the humans have, over the last few decades, started to look around in the Solar System. Apart from astronomy, and allied sciences - there have been space landing missions to study the various planets in-situ e.g. the Apollo Program,the Venera Program, proposed Chang'e, various Mars landers (Curiosity, Opportunity, to name a couple)
Movement however is not only about motive power, and direction. It is also about acceleration and deceleration as & when necessary. Motive power provides acceleration, and maintains velocity to these rover missions. I can't recall encountering a brake system in reading about rovers on the internet. Ergo, the brake system is friction, and gravity.
- How do rovers brake?
- Was a brake system designed for extra-terrestrial use?
- What would go into design/construction of a brake system for extra-terrestrial use?