Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Could using the gravity of another celestial body allow for something like a bi-elliptic transfer
that uses less delta-v than the theoretical "infinite apogee" delta-v requirement?
If yes, has such a transfer ever actually been performed?
Do you mean like this? In that case, a geosynchronous satellite stranded in a 51° inclination orbit used a very high apogee transfer with two lunar flybys at the high apogee to remove 40° of that inclination.
Required, but never shown