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Deimos is the small moon of Mars. The surface gravity is 0.003m/s2 (compare to Earth @ 9.807 m/s2). In theory a person with a bicycle could launch from and land on Deimos with a bicycle and a ramp.

A variation of the loop below, could in theory, be used increase traction on Deimos for take off and landing.

Bicycle daredevil Diavolo loops the loop

But would you actually be able to ride a bicycle on Deimos? With only human power would there be enough friction to move forward or turn?

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    $\begingroup$ Do you mean on a specially constructed surface, or on the actual natural surface of the planet, craters and all? Normal inflated rubber tires, or "Deimos-special" tires? I mean the tires and ramps could have magnets or 22nd century nano-intelligent SpaceVelcro®. What are the constraints? $\endgroup$ – uhoh Jun 12 '16 at 11:02
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    $\begingroup$ I had not thought of magnets nor Velcro (a tin or steel roadway, has lots of possibility now that you mention it. You can't use a power source to hold you down. Using rockets to give down pressure would be counter to the principal of human powered. I was thinking the natural surface primarily, but non-power consuming infrastructure would be fine. Loops, ramps, roads, trails, pretty much every place you ride a bike on Earth has had some infrastructure development. Bike modifications are unlimited, as long as you stay to human power only. $\endgroup$ – James Jenkins Jun 12 '16 at 22:24
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At that surface gravity, I don't see how it would be possible to ride a bicycle. The friction between the tires and the road is how the motion of the wheels is converted to motion of the bicycle and the rider.

0.3 milligee is practically no gravity at all. It would take 80 seconds to fall to the surface from a height of one meter - not so much a fall as a lazy drift. I don't think a person could even walk effectively on the surface of Deimos.

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  • $\begingroup$ JAXA's rovers agree. "Gravity on the surface of Ryugu is very weak, so a rover propelled by normal wheels or crawlers would float upwards as soon as it started to move. Therefore this hopping mechanism was adopted for moving across the surface of such small celestial bodies. The rover is expected to remain in the air for up to 15 minutes after a single hop before landing, and to move up to 15 m horizontally." $\endgroup$ – Camille Goudeseune Aug 6 at 20:18
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Yes, with suitable modifications.

The loop must be ferrous. Your bike needs strong magnets in the wheels. You will start out with low friction and have to pedal very gently but as you build up your speed your friction will increase. Arrange the loop so you can go round and round as many times as you want before leaving it. You could build up substantial speed that way, plenty sufficient for an escape orbit.

If your guidance was good enough you could land the same way--enter the loop and gently apply your brakes. You wouldn't have much margin, though, I can't imagine such a landing system ever being actually used.

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  • $\begingroup$ To what extent do magnets (or velcro) holding you to the track resist the force you are applying to move to a different place on the track? $\endgroup$ – WGroleau Sep 5 '18 at 2:58
  • $\begingroup$ @WGroleau Magnets, not velcro will have no effect on your movement around the track. If the magnets are on the rim the ones approaching the ground pull the wheel around exactly the same amount as the ones moving away retard you. If you have a fixed magnet behind the wheel it's not moving toward or away. $\endgroup$ – Loren Pechtel Sep 5 '18 at 3:26
  • $\begingroup$ But the one touching the track resists being removed from the track. When I've tried to pull two magnets apart, it seems the force required is not linearly proportional to the distance. $\endgroup$ – WGroleau Sep 5 '18 at 3:28
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    $\begingroup$ @WGroleau But while you're removing one from the track you're putting another on the track. The two forces balance. $\endgroup$ – Loren Pechtel Sep 5 '18 at 3:31

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