Perigee

A perigee is the point in any orbit nearest to the body being orbited.

In 2267, Captain James T. Kirk ordered Hikaru Sulu to increase the USS Enterprise (NCC-1701)'s orbit of Gamma Hydra IV to a 20,000 mile perigee, and under the influence of a virus that caused rapid aging repeated the same order a few minutes later. 

In 2366, the crew of the USS Enterprise (NCC-1701-D) attempted to correct the decaying orbit of Bre'el IV's moon when it reached its perigee.