Questions tagged [gravity]

Questions regarding the attractive force present between two masses. If about research in artificial gravity (i.e. manmade substitutes for gravity), please use the artificial-gravity tag.

9 questions with no upvoted or accepted answers
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For the mathematical relationship between J2 (km^5/s^2) and dimensionless J2 - which one is derived from the other?

The term $J_2$ seen in discussions of nodal precession of orbits (e.g. sun-synchronous) appears to come in two flavors. For example, in the Wikipedia article Geopotential model it has a value of $1....
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65 views

Variable Gravity, how long in each?

Centrifugal force can be used to simulate gravity in space vehicles. Assume the "gravity" in our space vehicle can provide environments ranging from 2 gravities to none (micro), either by changing ...
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214 views

Why would the dual keel space station design have been more stable?

According to the space station Freedom wikipedia page and this reddit thread, a dual keel structure would have been more stable than the final ISS design. Can someone explain why? And if a gravity ...
4
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236 views

extreme longevity of geostationary orbits

I was speculating that geostationary satellites could be around possibly for billions of years (i.e. much beyond the point where plate tectonics would have erased all traces of human civilization on ...
3
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52 views

If you fell into a crater on the moon in your spacesuit and no jetpack, is there a way to use low gravity to get out of the hole?

If you fell down a crater or hole on the moon, is there a way to exploit microfravity/low gravity to get to the top? Lets say your survived a fall into Aristarchus crater on the moon with a slow slide ...
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56 views

Seismic effects resulting from tidal action on Ganymede and Europa

What kind of seismic activity is going to be generated by the tidal forces exerted on these two moon's ice sheets by Jupiter? Would it be a great enough differential in the ice sheets to preclude ...
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150 views

Satellite altitude variances in orbit

I understand that all satellites must have burn corrections to keep their orbits where they are needed. However my question is specifically about what those changes are in magnitude from the desired ...
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93 views

How much does it cost to land on a lunar mascon?

This answer to Delta-v for landing on the moon estimates that to go from a circular orbit at 110km to a landing on a spherical Moon would require an absolute minimum of 1736 m/s and the Apollo landers ...
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111 views

Are there clusters of small asteroids in the Kuiper or asteroid belt which could threaten the Earth?

I watched an episode of Curious Droid talking about the types of impacts of asteroids the size of Near Earth Objects. Are there clusters of small asteroids which are gravitationally bound together (or ...