Lowest Stable Low Earth Orbit?

[Skeptoid]

What would it be for the surface of the Moon?

Hans

Orbital velocity = 1680m/s, taking 1.8 hours to complete an orbit.

 

[MRC_Hans]

Cool, thanks! I CAN do math myself, but not if I can avoid it, heheh. Mmm, that's pretty fast for bullets (re. the short story I mentioned). Two to three times your average riffle bullet, but then, it was SF.

Hans

 

[Soapy Sam]

What would be the fastest reasonable time for a forced orbit of Earth? (ie upside down, accelerating downwards to counteract inertial slingshot effect and probably unconscious)?

Puck could throw a girdle about the Earth in 90 minutes I seem to recall. Nasa could beat that, but what if we were seriously pushing for a record?

 

[MRC_Hans]

That would not be an orbit, that would be a powered flight.

Using present technology: Impossible. The amount of fuel you needed to bring would be forbidding.

Using Sci Fi technology: Anything is possible.

Hans

 

[QuarkChild]

Okay, using the equation for orbital velocity, V_o = (GM/R)^1/2 (which is equivalent to the equation you used), I get 3554m/s for a small mass orbiting at Mars' surface. But I'm getting 1.66 hours per orbit. I think you forgot to double the radius when you calculated Mars' circumference.

Agreed. I just used your 3554m/s value and got 1.67 hours.