Lunar Orbiter 4 was designed to take advantage of the fact that the three previous Lunar Orbiters had completed the required needs for Apollo mapping and site selection. It was given a more general objective, to "perform a broad systematic photographic survey of lunar surface features in order to increase the scientific knowledge of their nature, origin, and processes, and to serve as a basis for selecting sites for more detailed scientific study by subsequent orbital and landing missions". It was also equipped to collect selenodetic, radiation intensity, and micrometeoroid impact data. The spacecraft was placed in a cislunar trajectory and injected into an elliptical near polar high lunar orbit for data acquisition. The orbit was 2706 km x 6111 km with an inclination of 85.5 degrees and a period of 12 hours. Lunar orbiter 1 (large). ... NASA Logo Listen to this article · (info) This audio file was created from the revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... Langley Research Center (LaRC) Oldest of NASAs field centers, LaRC is located in Hampton, Virginia, and focuses primarily on aeronautical research. ... For other moons in the solar system see natural satellite. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... May 4 is the 124th day of the year in the Gregorian calendar (125th in leap years). ... 1967 was a common year starting on Sunday of the Gregorian calendar. ... UTC also stands for the University of Tennessee at Chattanooga Coordinated Universal Time or UTC, also sometimes referred to as Zulu time, the basis for civil time, differs by an integral number of seconds from atomic time and a fractional number of seconds from UT1. ... Mercury Atlas 9 rocket and capsule on pad The Atlas is a venerable line of space launch vehicles built by Lockheed Martin. ... October 31 is the 304th day of the year (305th in leap years) in the Gregorian Calendar, with 61 days remaining, as the final day of October. ... 1967 was a common year starting on Sunday of the Gregorian calendar. ... Mass iz a property of physical objects that, roughly speaking, measures the amount of matter they contain. ... The elements of an orbit are the parameters needed to specify that orbit uniquely, given a model of two ideal masses obeying the Newtonian laws of motion and the inverse-square law of gravitational attraction. ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... In astrodynamics, under standard assumptions any orbit must be of conic section shape. ... Inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit and is the angular distance of the orbital plane from the plane of the reference (usually planets equator or the ecliptic), stated in degrees. ... Apollo Program insignia Project Apollo was a series of human spaceflight missions undertaken by the United States of America using the Apollo spacecraft and Saturn launch vehicle, conducted during the years 1961–1972. ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ...

After initial photography on May 11, 1967 problems started occurring with the camera's thermal door, which was not responding well to commands to open and close. Fear that the door could become stuck in the closed position covering the camera lenses led to a decision to leave the door open. This required extra attitude control maneuvers on each orbit to prevent light leakage into the camera which would ruin the film. On May 13 it was discovered that light leakage was damaging some of the film, and the door was tested and partially closed. Some fogging of the lens was then suspected due to condensation resulting from the lower temperatures. Changes in the attitude raised the temperature of the camera and generally eliminated the fogging. Continuing problems with the readout drive mechanism starting and stopping beginning on May 20 resulted in a decision to terminate the photographic portion of the mission on May 26. Despite problems with the readout drive the entire film was read and transmitted. The spacecraft acquired photographic data from May 11 to 26, 1967, and readout occurred through June 1, 1967. The orbit was then lowered to gather orbital data for the upcoming Lunar Orbiter 5 mission. May 11 is the 131st day of the year in the Gregorian Calendar (132nd in leap years). ... 1967 was a common year starting on Sunday of the Gregorian calendar. ... May 13 is the 133rd day of the year in the Gregorian Calendar (134th in leap years). ... May 20 is the 140th day of the year in the Gregorian Calendar (141st in leap years). ... May 26 is the 146th day of the year in the Gregorian calendar (147th in leap years). ... May 11 is the 131st day of the year in the Gregorian Calendar (132nd in leap years). ... May 26 is the 146th day of the year in the Gregorian calendar (147th in leap years). ... 1967 was a common year starting on Sunday of the Gregorian calendar. ... June 1 is the 152nd day of the year in the Gregorian calendar (153rd in leap years), with 213 days remaining. ... 1967 was a common year starting on Sunday of the Gregorian calendar. ... Lunar Orbiter 5, the last of the Lunar Orbiter series, was designed to take additional Apollo and Surveyor landing site photography and to take broad survey images of unphotographed parts of the Moons far side. ...

A total of 419 high resolution and 127 medium resolution frames were acquired covering 99% of the Moon's near side at resolutions from 58 meters to 134 meters. Accurate data were acquired from all other experiments throughout the mission. Radiation data showed increased dosages due to solar particle events producing low energy protons. The spacecraft was used for tracking purposes until it impacted the lunar surface due to the natural decay of the orbit no later than October 31, 1967, between 22--30 degrees W longitude. October 31 is the 304th day of the year (305th in leap years) in the Gregorian Calendar, with 61 days remaining, as the final day of October. ... 1967 was a common year starting on Sunday of the Gregorian calendar. ...

External links

• DESTINATION MOON: A history of the Lunar Orbiter Program (PDF) 1976

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