A satellite in low-earth orbit with a 90-min period passes over the north pole, headed south along the 0^◦ line of longitude passing through Greenwich, England.

(a) What is its longitude when it reaches the latitude of Greenwich \(\left(\lambda=50^{\circ}\right)\) ?

(b) When it reaches the equator, what angle does its trajectory make with the equator as seen by an observer on earth?

(c) How close does it come to passing over the south pole?