/sci/ - Science & Math

>>15625930
>>15626045
A statite that moves so as to hover over the lunar poles seems feasible though I'd use a magsail instead of a photon sail

statites when?

>>15368868
66 days on-planet is bullshit. Do proper exploration or don't bother going.

>A Polestat will use a solar sail, not orbital motion, to counteract the Earth’s gravity. This will be in contrast to all the thousands of objects that are moving in orbits in which the Earth’s gravitational pull is exactly balanced by the centrifugal force generated as a result of their motion.
>A Polestat will use its solar sail to ‘levitate’ in space above the shadowed, or dark, side of the rotating Earth. The force of light pressure will exactly counterbalance the force of the Earth’s gravity
>A Polestat does not have to be positioned directly opposite the Sun. It can be placed anywhere in a large volume over the shadowed side of the Earth. For this reason, a very large number of Polestats can be placed in the sky without interfering with each other’s broadcasts.
>In practice, statites will be at angles of 30 degrees to 40 degrees from the polar axis. From the viewpoint of an observer on the Earth, the statite will rotate around the pole once every solar day (24 hours). Ground stations will have to have their antennas on a polar mount with a 24-hour clock drive.
>Using reasonable numbers for the size of a practical solar sail and the mass of the payload, the typical distance of a Polestat from the centre of the Earth will be between 30 and 100 Earth radii. For comparison, geosynchronous orbit is at 6.6 Earth radii and the Moon is at 63 Earth radii.
>A Polestat could even be placed directly above the North or South Pole of the spinning Earth. At first glance, this seems to be impossible, because during the summer season the Polestat would have to be above the sunlit side of the Earth, and the force of solar light pressure and the Earth’s gravity would be in the same direction.
>Colin McInnes of the University of Glasgow has shown, however, that a Polestat can hover stably above a pole at an altitude of 270 Earth radii.
https://www.newscientist.com/article/mg12917594-000-science-polar-satellite-could-revolutionisecommunications/