Re:Japan starts space elevator experiments
by leereeves on Tuesday September 04, 2018 @11:48AM
(#17909852)
You're right, the portion of a rocket's exhaust that is recaptured by the Earth would raise or lower the angular velocity a bit, depending on direction, and gravity between the Earth and the spacecraft would have a tiny effect in the opposite direction.
Those are separate from the disconnect I was talking about; I meant a gentle disconnect after which the spacecraft remains in orbit.
It does if your spaceship escapes from Earth in a prograde[1] direction (equivalent to Earth throwing a ball forward, causing a retrograde reaction upon the Earth). This type of escape trajectory is necessary to reach any destination farther from the Sun (Mars, asteroids, etc). It's a tiny change obviously, but it's non-zero.
Note that returning from Mars/asteroids and aerobraking should add angular momentum, speeding up the Earth and at least partly counteracting this effect.
[1] https://en.wikipedia.org/wiki/Retrograde_and_prograde_motion