(n.) That point of a planet's or comet's orbit which is most distant from the sun, the opposite point being the perihelion.

Earth insertion LEM LM acme all apex aphelion astronomical longitude attitude-control rocket autumnal equinox ballistic capsule brow burn cap capstone capsule ceiling celestial equator celestial longitude celestial meridian circle climax cloud nine colures crest crown culmen culmination deep-space ship docking docking maneuver ecliptic edge end equator equinoctial equinoctial circle equinoctial colure equinox extreme extreme limit extremity far cry far piece ferry rocket fuel ship galactic longitude geocentric longitude geodetic longitude giant step good ways great circle great distance heaven heavens height heliocentric longitude high noon highest degree highest pitch highest point injection insertion limit long chalk long haul long range long road long run long step long way longitude lunar excursion module lunar module manned rocket maximum meridian module moon ship mountaintop multistage rocket ne plus ultra no place higher noon nth degree orbit parking orbit peak perigee perihelion period pinnacle pitch point pole reentry ridge rocket seventh heaven shuttle rocket sky small circle soft landing solstitial colure space capsule space docking space rocket spacecraft spaceship spire summit the whole tidy step tip tip-top top trajectory upmost upper extremity uppermost utmost utmost extent uttermost vernal equinox vertex very top zenith zodiac zone