When an Orbiting Spacecraft Is Closest to the Moon

This page is the CodyCross answer for the clue below from Past and Present Tech, Group 1450, Puzzle 3 (Fax Machines).

Question is: When an Orbiting Spacecraft Is Closest to the Moon

and the answer is: PERILUNE

Word Meaning:

PERILUNE — (astronomy) The point of an elliptical lunar orbit where the distance between the satellite and the Moon is at its minimum.

Definitions from Wiktionary.