In this recently asked question on a large, sun blocking object it is pointed out in the comments that there would be ~10e7 N of thrust from the sun due to solar wind.

My question is does there exist a point, similar to the sun-Earth Lagrange point, where the gravitational and the solar wind forces will cancel out and so the described object would remain stationary without the need for any (or at least very little) maintained thrust?

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    $\begingroup$ This sounds like a question for Physics or Space Exploration, more than a question about building a fictional world. $\endgroup$ – sphennings Jan 17 '18 at 15:06
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    $\begingroup$ Great places to put space stations are on-topic on this site; I think this should stay open. $\endgroup$ – kingledion Jan 17 '18 at 15:18
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    $\begingroup$ Welcome to the Site! This is something that probably does belong over in Physics because I'm sure you can derive a specific formula for it. $\endgroup$ – Paul TIKI Jan 17 '18 at 15:18
  • $\begingroup$ This belongs over at physics but the answer (I believe) they'll give you is essentially: No, the solar wind will only push radially but deviating from the radius of the lagrangian point will effect the object's orbit tangentially so it would no longer have the same orbital period as the Earth. $\endgroup$ – Lio Elbammalf Jan 17 '18 at 15:22
  • $\begingroup$ I was torn between the change in question type and leaving it here as it relates to a world-building question. Thanks for the heads up though! $\endgroup$ – Bytes Jan 18 '18 at 9:52

There is no single point like that. Forces created by gravity and rotation are independent* from actual mass or shape of the satellite. That's why we can talk about such points, universally.

Force created by solar wind, light pressure and so on depends on the shape of your satellite, surface, how reflective surface is, and so on. Thus, at the same point it can be quite large for one satellite** and rather minuscule for another.

That said, you can replace some of centrifugal force with solar sail power, and do some maneuvering by changing sail's orientation. How far from Lagrangian points your point of balance would be depends solely on the design of your craft, and thus, indirectly, tech level available in your world. In theory, if material wouldn't be a problem, you could even have a stationary platform that does not circle around your star at all. Or even propel entire star system with Shkadov Thruster.

* With assumption that mass of the object in L point is irrelevant in comparison with Sun and Earth.

** We don't have a word for pseudo-satellites on forced orbits, so I'll just use closest word we have.


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