For old time space enthusiasts like myself, it seems that no lunar mission is complete without an obligatory Earthrise (or Earthset) image. The spectacle of our cloud shrouded home planet hovering above the bleak lunar horizon never fails to inspire awe as we realize our place in the vast cosmos. While the internet is filled with such images from more recent lunar missions, we need to go back six decades to find the very first example of an Earthrise photograph. This first image was originally taken during NASA’s Lunar Orbiter 1 mission flown in 1966 during those heady years leading up to the Apollo lunar landing missions.
An Earthset image taken on April 6, 2026 during NASA’s ten-day Artemis II crewed mission around the Moon. Click on Image to enlarge. (NASA)
NASA’s Lunar Orbiter
Lunar Orbiter, under the management of NASA’s Langley Research Center, was designed for a single task: orbit the Moon and take medium to high-resolution images of the lunar surface in order to identify and characterize potential Apollo and unmanned Surveyor landing sites. A total of five missions were planned in the 1966-1967 time frame to meet the project’s objectives. The 385-kilogram, three-axis stabilized spacecraft was built by Boeing and designed around a 66-kilogram photographic package built by Eastman-Kodak. A photographic system, where the exposed film was developed onboard and subsequently scanned for transmission to Earth, was chosen over either an analog or digital television-based system because of the former’s superior resolution and image storage capacity at that time.
A schematic diagram of Lunar Orbiter’s photographic subsystem built by Eastman-Kodak. Click on image to enlarge. (NASA)
Lunar Orbiter’s photographic subsystem, based on Kodak’s previously classified reconnaissance satellite work for the Department of Defense, was housed in an ellipsoidal aluminum alloy shell pressurized with dry nitrogen at 120 millibars. Viewing through a quartz window in the side of the shell were a wide-angle 80 mm focal length, f/4.5 lens and a 610 mm focal length, f/5.6 narrow angle lens which would provide medium and high-resolution views of the lunar surface, respectively. These lenses simultaneously produced a pair of images on a single roll of 70 mm Kodak SO-243 high-contrast, fine grain aerial mapping film using exposures of 1/25th, 1/50th, or 1/100th of a second.
A view of Lunar Orbiter’s photography system with its cover removed. (NASA/Langley)
About 80 meters of film were carried aboard Lunar Orbiter, allowing as many as 212 high and medium-resolution image pairs to be taken. The 610 mm lens was also used by an electro-optic velocity/height sensor that slowly moved the photographic film during an exposure as part of a motion compensation system to reduce the effects of image smearing caused by spacecraft orbital motion. During its 15 to 30 day-long photography mission in a nominal 45 by 1,850-kilometer mapping orbit, the best resolution for the narrow and wide-angle images was expected to be one and 8 meters, respectively.
The exposed film was developed as the photographs were taken using Bimat Transfer Film, which employed spools of a webbing impregnated with the appropriate developing and fixing chemicals that would come into contact with all parts of the exposed film for at least 3½ minutes. The process was similar to that employed by Polaroid instant cameras of that era. Since the photographs could be taken faster than they could be processed, a set of takeup reels were included, allowing up to 21 image pairs to be stored. Once the images were taken and the film was developed, the images were scanned by a 5 micron wide beam of high intensity light at a resolution equivalent of 287 lines per millimeter.
A schematic diagram of Lunar Orbiter’s film scanning system. Click on image to enlarge. (NASA)
A photomultiplier tube detected the light beam, whose intensity was altered by the film’s image density, and the appropriate electronics converted this signal into a form to be transmitted back to Earth. Each image pair could be transmitted in 43 minutes when both the Earth tracking station and the Sun were visible. The scanned photographs were the equivalent of an 8,360 by 9,880 pixel image for the wide-angle and an 8,360 by 33,288 pixels for the narrow-angle views. The effective storage capacity of this photographic system was the equivalent of several tens of gigabytes of data compared to 615 kilobyte storage capacity of the then state-of-the-art digital magnetic tape recorder employed by the imaging system on Mariner 4 during its historic flyby of Mars in July 1965 (see “Mariner 4 to Mars”).
Diagram showing the major components of the Lunar Orbiter spacecraft. Click on image to enlarge. (NASA)
The photographic subsystem was mounted on a 1.4-meter diameter equipment deck located at the base of the 2.0-meter tall, roughly conical-shaped spacecraft. Also mounted on this deck were a Canopus star sensor, five Sun sensors, and an inertial reference unit all used to determine Lunar Orbiter’s attitude to an accuracy of ±0.2°. A flight programmer possessed a 128-word memory that was able to control spacecraft activities for 16 hours’ worth of photography work. Under the control of this unit, the photographic system could be programmed to take groups of four, eight, or sixteen photographs in a variety of patterns of selected sites during each orbital pass.
The Lunar Orbiter 1 Mission
Lunar Orbiter 1 was successfully launched from Cape Kennedy’s Launch Complex 13 at 3:26:00.7 PM EDT (19:48:00.7 GMT) on August 10, 1966 using an Atlas-Agena launch vehicle. While a few technical issues were encountered during the spacecraft’s cruise to the Moon, Lunar Orbiter 1 successfully fired its main engine to enter a 189 by 1867-kilometer orbit around the Moon with an inclination of 12.2° at 15:43 GMT on August 14. The following day, during its sixth orbit around the Moon, Lunar Orbiter 1 began to readout and transmit its “Goldstone test film”. This was a pre-exposed leader of the film supply that was meant to provide an end-to end test of not only the spacecraft’s photographic and transmission subsystems, but also the receiving and image reconstruction hardware back on the Earth.
This schematic diagram shows the major steps required for Lunar Orbiter to transmit its photographs and have them reconstructed back on the Earth. Click on image to enlarge. (NASA)
At 9:49:58 GMT on August 21, Lunar Orbiter 1 fired its engine again to trim its orbit to 58 by 1,855 kilometers with an inclination of 12.3° in preparation for the formal start of its mapping mission. The perilune was lowered again on August 25 to an altitude of 40 kilometers to get the photographic subsystem’s malfunctioning motion compensation system to work properly. While the wider angle images looked fine, the highest resolution images taken near perilune were hopelessly smeared limiting the image quality of the near side photographs of potential Apollo landing sites.
It was found that the Bimat webbing used to process the photographs would stick to the film if left in place for too long causing damage like that seen in this enlargement. (NASA/LPI)
Early on in the mission, it was discovered that the Bimat webbing was sticking to the film damaging the photographs in places as a result. Originally the plan was to advance the Bimat at least once every 15 hours which meant that at least two images had to be acquired every four orbits. Because of the sticking issue, it was decided to expose some photographs during every orbit instead. Along with the extra images acquired to diagnose the high resolution image smearing issues, this necessitated a change in the photography plans with three of the primary targets getting half the originally planned coverage.
Diagram showing the geometry used by Lunar Orbiter 1 to secure the first-ever Earthrise photograph. Click on image to enlarge. (NASA)
But the need to take additional images during each orbit also opened up some opportunities for Lunar Orbiter’s camera. Program managers wanted to turn Lunar Orbiter away from its normal nadir-viewing attitude during one of its passes behind the Moon and capture the Earth rising above the lunar horizon. Making this maneuver away from the normal vertical orientation while out of touch with ground controllers was risky and opened the possibility, however remote, of losing Lunar Orbiter. The plan was opposed by the conservative Boeing engineers but NASA program officials thought the move was worth the risk. On the responsibility of NASA in case the mission was lost, the photograph was taken at 16:35 GMT on August 23 during the 16th orbit at an altitude of 1,198 kilometers above the surface. At the time the photograph was taken, the spacecraft was 379,720 kilometers from the Earth directly over Africa.
The medium resolution Lunar Orbiter 1 Frame 1102 capturing the first Earthrise as seen from the Moon on August 23, 1966. This image and subsequent images below have been reprocessed using modern techniques as part of the Lunar Orbiter Image Recovery Project. Click on image to enlarge. (NASA/LPI)
Here is the closeup of the high resolution Frame 1102 matching the medium resolution frame above. Click on image to enlarge. (NASA/LPI)
Lunar Orbiter 1 perfectly executed its commands to acquire the first-ever picture of the Earth as seen from the Moon and returned to its normal orientation afterwards. In addition to the view of the Earthrise, the medium resolution image also provided an oblique view of the lunar far side including a glimpse of the distinctive mare-filled Tsiolkovskiy Crater not observed since its discovery during the Soviet Luna 3 mission almost seven years earlier (see “Luna 3: Shedding Light on he ‘Dark Side’ of the Moon“).
With the successful return of these first of their kind Earthrise image, the feat was repeated with a similar imaging geometry during the 26th orbit at 13:02 GMT on August 25 at an altitude of 1,581 kilometers with the Earth visible slightly higher above the lunar horizon. In addition to the public relation value of the Earthrise photographs, scientists found the out-of-the-vertical views of the lunar surface to be useful as well. Plans for more oblique photography would be included in future Lunar Orbiter missions as a means of minimizing the Bimat sticking issues.
The medium resolution Lunar Orbiter 1 Frame 1117 capturing the Earthrise as seen from the Moon on August 25, 1966. Click on image to enlarge. (NASA/LPI)
Here is the complete high resolution Frame 1117 matching the medium resolution above. Click on image to enlarge. (NASA/LOIRP)
On August 29, 1966, Lunar Orbiter 1 finished its photography mission when it exhausted its film supply. Readout of the 205 exposed photographs began the next day and was completed on September 16 when the spacecraft began its extended mission. Despite the technical issues encountered during the mission, 75% of the objectives were met and the mission was deemed a success. With is supply of attitude control gas nearing depletion and with the continuing degradation of its various systems, Lunar Orbiter 1 fired its main engine one last time during 577th orbit on October 29. The spacecraft dropped from lunar orbit and crashed on the far side of the Moon at 6.7° north latitude, 162° east longitude at about 13:29 GMT. The mission of the first successful American lunar satellite was completed and the way was clear for the launch of the second Lunar Orbiter the following week (see “Lunar Orbiter 2 and the ‘Picture of the Century’”).
Related Video
Here is a film produced by Boeing, The Lunar Orbiter: A Spacecraft to Advance Lunar Exploration, summarizing what NASA hope to accomplish with the Lunar Orbiter Program.
Related Reading
“Lunar Orbiter 1: America’s First Lunar Satellite”, Drew Ex Machina, August 14, 2016 [Post]
“First Pictures: Earthrise from Apollo 8 – December 24, 1968”, Drew Ex Machina, December 24, 2023 [Post]
General References
Bruce K. Byers, Destination Moon: A History of the Lunar Orbiter Program, NASA TM X-3487, NASA History Office, 1977
Michael M. Mirabito, The Exploration of Outer Space with Cameras, McFarland, 1983
Raymond N. Watts, Jr., “Lunar Orbiter Surveys the Moon”, Sky & Telescope, pp. 192-196, Vol. 32, No. 4, October 1966
“Lunar Orbiter 1 Preliminary Results”, NASA SP-197, 1969