Definitions

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The point of an elliptical lunar orbit where the distance between the satellite and the Moon is at its minimum.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. periapsis in orbit around the moon

Etymologies

from Wiktionary, Creative Commons Attribution/Share-Alike License

From peri- ("near") + Latin lūna ("moon").

Examples

  • China's first lunar probe, Chang'e-1, successfully completed its first braking at perilune and entered the moon's orbit Monday morning, becoming China's first circumlunar satellite.

    NASA Watch: Keith Cowing: November 2007 Archives

  • A standard altimeter could not tell the astronauts when they reached their perilune because an altimeter was an instrument that determined altitude based on changes in atmospheric pressure and the Moon has no atmosphere.

    First Man

  • Aldrin reported that DOI had come off extremely well, and that it had put Eagle into almost the exact, predetermined perilune from which it was to start its final, powered descent.

    First Man

  • LRO's average altitude is about half that (31 miles, or 50 km), but to capture the new images, the controllers adjusted the orbit so that its lowest point - or perilune - was only 13 miles (21 km).

    TIME.com: Top Stories

  • Period: May 2009* operation: elliptical orbit, 20 km (perilune) at south pole and 100 km (apolune) at north pole* mission: same as phase 2.

    Spaceports

  • In this Lunar Orbit of Injection, the satellite's closest point from the moon (perilune) is 500 km and the farthest point (apolune) is about 7,500 km.

    Top Stories - Google News

  • He further said that the next deboost manoeuvre that will take the spacecraft from the present Lunar Orbit of Insertion (LOI) to the first lower orbit LO-1, which will have a perilune of 125 km, will be carried out after two and a half revolutions in the present orbit.

    The Hindu - Front Page

  • While the exact orbit determination will take a couple of hours, the ISRO release gave the nominal orbit parameters as 504 km perilune (the nearest point from the Moon's surface) and 7502 km apolune (the farthest point).

    The Hindu - Front Page

  • The nearest point of this orbit (perilune) lies at a distance of about

    rediff.com

  • At one o’clock in the afternoon Houston time, July 22, a NASA public affairs officer reported that Eagle had achieved lunar orbit, one with an apolune of 47.2 nautical miles and a perilune of 9.1 miles.

    First Man

Comments

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  • "Aldrin, from the July 31, 1969 Technical Debrief - 'We had two methods of computing altitude: one based on relative motion from the CSM and the other based on angular rate track of objects observed on the ground. We superimposed the two of them on one graph and re-arranged the graph a little bit with some rather last minute (pre-flight) data shuffling to give us something that the two of us could work on at the same time and to give indication of what the altitude and its time history appeared to be. With the communications difficulties that we were experiencing in trying to verify that we had a good lock-on (with Earth) at this point, I had the opportunity to get only about two or three range-rate marks (on the CSM). They appeared to give us a perilune altitude of very close to 50,000 feet, as far as I could interpolate them on the chart.'"

    - 'The First Lunar Landing' transcribed by Eric M. Jones, hq.nasa.gov.

    October 8, 2008