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Comment by aakil | Hacker News Reader

There's probably a radiation issue that wouldn't make it suitable for close to human contact. I wonder how much energy the rover needs to move around since the gravity there is considerably weaker.

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Rover mass is same on Earth or Mars. So acceleration costs the same. Low gravity also means less friction with the ground, making it somewhat harder to move on Mars.

Climbing hills would be easier on Mars.

Isn't there also an issue of impulse though? There must be an acceleration dip compared to earth since I'm basically pushing a mini cooper on earth but only a bicycle on mars. Note: I'm a scientist so I'm embarrassingly bad at physics.

It would be easier to lift the rover perhaps, but F=ma, so since the mass of the rover hasn't changed, neither has the acceleration you can develop for a given force applied.

Isn't the friction dependent upon the normal force which on Mars would be less. Therefore, shouldn't the force required to overcome that also be less?

Wheels need friction to develop acceleration. So its a negative not a positive.

It's only a negative if the vehicle needs to accelerate quickly. So sufficient friction is sufficient, not a negative or a positive.

Given that the batteries store roughly 2.4 kW-h, it's probably safe to assume that the max drive power is less than 500 watts (2.4 kW-h / 10 hours -> 240 watts). Earth side electric vehicles commonly have drive power over 100 kilowatts.

Absolutely, if you were pushing a block along the ground. Fortunately modern "wheel" technology reduces the bearing friction so much that it is no longer a factor. The only friction left is the friction holding the wheel to the ground. This is reduced in reduced gravity, such that wheels are more likely to slip.

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