Q. [We were learning on the Daf about the fact that you have to hold the lulav and esrog the upside way they normally grow. Since it is only a matter of time until we will be traveling in space,] how do you hold the lulav in space where there is no gravity or only artificial gravity on a space station?

A. Horav Shlomo Miller Shlit”a pointed out that there is no real space of zero gravity. Even when floating in outer space you are actually in an orbital free fall towards the Earth and very much affected by earth’s gravitational forces, otherwise you would speed away from the planet into deep space. At the point of equilibrium of gravitational pull, that is where the attracting forces of two heavenly bodies, such as the Earth and the Moon are the same, in the unlikely event that you would be holding then a lulav in your hand, you would prefer the derech gedilosson in reference to Earth. He does not consider artificial gravity, created by the centrifugal forces of a rotating space station, as the normal gravity provided by earth and derech gedilosson would still be in reference to the planet, not the station.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a