periselene

A zero or partical burn, not complicated by guidance malfunction, which results in a velocity of more than 7550 ft/sec at periselene places the prime transport vehicle (PTV) on a hyperbolic escape trajectory out of the lunar sphere of influence.

1971, Lunar Mission Safety and Rescue: Escape/rescue Analysis and Plan

The lunar module shifted into an elliptic orbit with a periselene altitude of 14.3 km ± 200 m and an aposelene altitude of 113.2 km. At periselene tests of the radar altimeter, which ensures the landing of the lunar module on the Moon's surface, were carried out.

1972, G. A. Skuridin, Space physics and spacecraft, page 65