Apollo 17 Mission
The photographic objectives of the Apollo 17 mission were to provide precisely oriented mapping camera photographs and high-resolution panoramic camera photographs of the lunar surface, to support a wide variety of scientific and operational experiments, and to document operational tasks on the lunar surface and in flight.
The Apollo 17 mission was designed to obtain the most extensive quantity and variety of photography of any mission thus far. There were several different varieties of photographic equipment, both on the surface and in orbit. The camera equipment operated on the lunar surface or in the LM by Astronauts Scott and Irwin included three 70-millimeter Hasselblad Data Cameras (HDC, LM1, LM2), a 16-millimeter Data Acquisition Camera (DAC), and a color TV camera (LM4) or Lunar Surface TV camera. The main photographic tasks during orbit were performed with the Mapping Camera System and the Panoramic Camera, which were in the SIM bay. Various tasks were also accomplished using four command module cameras: a 70-millimeter Hasselblad electric camera, a 16-millimeter Maurer DAC, a 35-millimeter Nikon, and a Westinghouse color TV camera.
Lunar Surface TV Camera. The RCA television camera (LM4) used on the lunar surface could be operated from three different positions: mounted on the LM modularized equipment storage assembly (MESA), mounted on a tripod and connected to the LM by a cable, and installed on the LRV with signal transmission through the lunar communication relay unit. While on the LRV, the camera was mounted on the ground-controlled television assembly. The camera could be aimed and controlled by the astronauts or remotely controlled by personnel in the mission control center. Color was achieved by using a rotating disc driven by a 600-rpm motor. Lunar color scenes were scanned, field sequentially, and down-linked serially to the Manned Space Flight Network. Video was received and recorded from lunar distance at any of the three Deep Space Stations.
Mapping Camera System. The purpose of the mapping camera system was to obtain photographs of high geometric precision of all lunar surface features overflown by the spacecraft in sunlight. This camera system consisted of a 76-millimeter Fairchild mapping camera (SIM3) using 5-inch film, a 3-inch stellar camera using 35-millimeter film, and a laser altimeter. The electrically operated system was powered by 115 volts, 400 Hertz alternating current (AC), and 28 volts direct current (DC) spacecraft power.
The laser altimeter, when operating independently, gave altitude data at a frequency of three data points per minute when the mapping camera was off and approximately 2.5 points per minute when the camera was on. The altimeter malfunctioned during the orbital mission, and no data were obtained after revolution 38. A complete girth of the Moon with the altimeter was acquired on revolution 15/16; sporadic data were recorded otherwise. About 30% of the planned altimeter data was obtained.
The stellar camera was mounted on an axis at 96° from that of the mapping so that it photographed the sky while the mapping camera photographed the lunar surface. Any photography designated "stellar" refers to this photography, except that discussed as Special Photography and Experiments. The film cassette containing stellar and mapping photography was removed from the SIM bay by the command module pilot during trans-Earth trajectory and was returned to Earth in the command module.
Panoramic Camera. The optical bar panoramic camera consisted of three major assemblies: (1) the roll frame assembly, which basically provided the platform for the rotating lens system; (2) the gimbal structure assembly, which rocked the roll frame assembly back and forth to provide for stereo photography and to compensate for the forward motion of the vehicle; and (3) the main frame assembly, which attached to the vehicle and provided a platform for the film transport system as well as for the roll frame and gimbal structures. Two mirrors folded the 610-millimeter (24-inch) focal length into a more compact configuration, and the camera had a relative aperture of f/3.5 and field of view (FOV) of 10.77° (20 kilometers of surface and 100 kilometers altitude). The lens was rotated about an axis parallel to the SM, and a capping shutter opened during the time the lens passed through a 108° arc (320 kilometers of lunar surface at 100 kilometers altitude) below the vehicle. The light admitted was focused through a variable width slit from a minimum opening of 0.38 millimeters to a maximum of 7.6 millimeters. The slit width and scanning rate (rate of rotation of the lens) established the photographic exposure time.
The camera was mounted on rails that were attached to shelves in the SIM. During camera operation, the SM positive X axis had to be in the direction of the velocity vector. The film takeup cassette was removed from the panoramic camera by the command module pilot during trans-Earth trajectory, and was returned to Earth in the command module.
70-millimeter Hasselblad Electric Camera. The 70-millimeter Hasselblad electric camera was used during rendezvous and docking operations and during translunar coast and trans-Earth coast to photograph the Earth and Moon. It was also used to acquire dim-light, earthshine, and ultraviolet photographs (using a 105-millimeter lens). This Hasselblad camera had a motor-driven mechanism that was powered by two sealed nickel-cadmium batteries. The mechanism advanced the film to the next frame and cocked the shutter whenever the camera was activated. The normal 80-millimeter lens could be easily replaced with a 105-millimeter, 250-millimeter, or 500-millimeter lens.
35-millimeter Nikon Camera. The 35-millimeter Nikon camera was mounted in the righthand rendezvous window and periodically made time exposures during the dark portion of the lunar orbit. The purpose of the experiment was to determine whether, and to what extent, reflection from dust particles at the Moulton point contributes to the gegenschein. The gegenschein region was not acquired but, instead, the camera photographed another part of the Milky Way as a result of a translation error in coordinates from the ground.
Westinghouse Color TV Camera. A Westinghouse color television camera, used in the command module, could be handheld or bracket-mounted. The scanning rate for the camera was the commercial 30 fps, 525 scan lines lines per frame. The resolution of the camera was 200 TV lines per picture height with an aspect ratio of 4:3 and a range or operation from 5 to 12,000 f-c. A 5-centimeter black-and-white video monitor, which could be Velcro-mounted on the camera or at various locations in the command module, aided the crew in focus and exposure adjustment. A camera ringsight also aided in directing the lens at the desired target.
Both the service module and the command module performed orbital photographic tasks. The main photographic tasks during orbit were performed with cameras in the scientific instrument module (SIM), located in the service module. In the SIM bay were two photographic packages: the mapping camera system and the panoramic camera. The service module tasks were to obtain high-quality metric/mapping photographs and high-resolution panoramic photographs in both stereoscopic and monoscopic modes.
Photographs taken from lunar orbit provide synoptic views for the study of regional lunar geology. The photographs were used for lunar mapping and geodetic studies and were valuable in training the astronauts for future lunar missions.
Metric/Mapping Camera Photography. The mapping/metric photography was performed using the Mapping Camera Subsystem, which included the metric camera, the stellar camera, and the laser altimeter. This equipment was mounted in the SIM bay section of the CSM. This photography was collected to be used for establishing a unified selenodetic reference system, for photomapping at scales as large as 1:250,000, and for synoptic interpretation of geologic relationships and surface material distribution.
The Mapping Camera was operated on 16 passes during the period of lunar orbit. The camera was also used twice during trans-Earth coast, the first time for 2 hours and 29 minutes, and a second time for approximately 13 minutes. Camera operation was near normal. The deployment mechanism exhibited an anomaly; however, this problem had no effect on acquisition of the photography.
Inflight contingencies required rescheduling of planned photography, resulting in a loss of approximately 10% of the preplanned photography. A total of 3481 frames were taken, but only 2491 frames are considered usable. Some frames are blank as a result of exposure during operation with the laser altimeter on the darkside.
Additional Details on the Metric and Panoramic Photography
Astronaut Ron Evans is pictured retrieving film canisters from the Mapping and Panoramic Cameras in the Service Module. He is holding a handrail on the Service Module, and his body is extended over the open instrument bay. The Mapping Camera film canister is near his left elbow. At the rear of the Service Module, the Lunar Sounder Experiment's VHF antenna extends toward the top right corner of the photograph.
Apollo 15, 16, and 17 carried a set of cameras in the Scientific Instrument Module of the Service Module. These cameras were used to obtain high-resolution photographs of the lunar surface, for use both in studying the geology of the surface and for producing detailed topographic maps of the surface. These cameras included a Metric Camera, a Panoramic Camera, and a Stellar Mapping Camera. The Metric and Stellar Mapping Cameras were operated as a unit along with the Laser Altimeter. The Panoramic Camera was operated separately, but was often used at the same time as the Metric Camera. The film canisters used by these cameras were retrieved from the Service Module and stowed in the Command Module during a spacewalk by the Command Module pilot on the return trip to Earth.
The Metric Camera obtained pictures of the surface covering 165 kilometers on a side, with a horizontal resolution of 20 meters, based on a nominal spacecraft altitude of 110 kilometers. The Stellar Mapping Camera obtained photographs of star fields at the same time, which were used to establish the spacecraft's precise orientation, thus improving the accuracy of the resulting lunar maps. The Panoramic Camera obtained pictures of narrow strips, 20 kilometers wide in the direction of spacecraft motion and 320 kilometers long across the spacecraft's ground track. These pictures had extremely high resolution, showing features just 1 to 2 meters across. Photographs with both cameras were taken so that there was substantial overlap in the ground coverage of consecutive photos. This allowed the technique of stereo photography to be used to determine the heights of features shown in the photos. Under ideal conditions, the heights of these features could be determined to an accuracy of better than 10 meters. The results of this stereo photography project were used in producing topographic maps.
During Apollo 17, the Metric Camera was used on 15 orbits and during the early hours of the return to Earth, obtaining 2140 usable photographs. The Panoramic Camera was used on nine orbits and during the early hours of the return to Earth, obtaining 1574 usable photographs. This covered virtually all of the Moon visible in sunlight to the Apollo 17 crew.
Examples of Apollo 17 Metric Photography
The Moon in Three Dimensions
Photographs taken while looking down from great heights, such as from an airplane or orbiting spacecraft, often have a two-dimensional quality to them, with little or no indication of how high the features shown in the image actually are. If a region is photographed from two different perspectives, the differences in appearance of the two photos can be used to determine the heights of features in the images. This is known as stereo photography and is conceptually similar to the process the human brain uses to merge the images from the left and right eyes into a single image that provides information about the distances to various objects.
The image shown here has been digitally processed to illustrate this stereo effect. It should be viewed with special red- blue stereo glasses. The red lens goes over the left eye and the blue (or green) lens goes over the right eye.
This image is 86 kilometers across and shows a portion of southwestern Mare Serenitatis. The Serenitatis impact basin, which is 920 kilometers in diameter, formed 3.89 billion years ago when a large asteroid or comet struck this part of the Moon. Large impact basins are typically surrounded by several mountain rings. The rough structures in the lower part of the image are the Haemus Mountains, which are part of one of the rings of the Serenitatis impact basin. The smoother regions in the upper part of the image are the mare plains, formed when basaltic lava flooded this region roughly 3.5 billion years ago. The mountains are 2 to 3 kilometers higher than the mare plains. The ridges in the upper right of the image and the valley-like graben in the upper left are similar to features seen elsewhere in Mare Serenitatis. Both the ridges and the graben formed when the weight of the basaltic lava caused the mare plains to buckle. The largest crater visible in this image is Sulpicius Gallus, which is 12 kilometers in diameter and 2.2 kilometers deep. As is typical of small lunar craters, Sulpicius Gallus has a relatively simple structure. Heights in this image are vertically exaggerated by a factor of 3.9. (Based on Apollo 17 Metric photographs AS17-1816 and AS17-1818. Stereo processing by Paul Schenk, Lunar and Planetary Institute. Stereo image © copyright Lunar and Planetary Institute, 1997.)
Example of Apollo 17 Panoramic Photography
The 610-meter (24-inch) ITEK panoramic camera obtained high-resolution panoramic photographs, in both stereoscopic and monoscopic modes, of the lunar surface during the Apollo 15, 16, and 17 missions. The camera provided 1- to 2-meter-resolution photography from an orbital altitude of 111 kilometers (60 nautical miles). The panoramic camera was located in the SIM bay of the Service Module. Panoramic photographs supported photographic data for the other command service module cameras and for the SIM experiments, scanning the lunar surface from lunar orbit, providing greater area coverage and higher resolution for given regions.
This spectacular panoramic view of the eastern limb of the Moon was exposed when the command service module was in a pitched-up attitude during revolution 62. The entire area of Mare Smythii, more than 400 kilometers from left to right, is visible. In the near field, the 150-kilometer-diameter crater Hirayama extends across the middle one-third of the bottom of the photograph. The crater Dreyer is just outside the extreme right corner.
Lunar surface photographs are primarily of three types: (1) surface activities, to document the condition, performance, orientation, or setting of equipment and the effectiveness of procedures; (2) sample documentation photographs, to record features or materials that were not collected; and (3) panoramic views, to provide for the accurate location of traverse stations and to provide the capability to reconstruct the geologic setting of the landing site.
Surface Activities. During the stay on the lunar surface, the commander (CDR) and the lunar module pilot (LMP) exposed more than 2200 frames in their Hasselblad DCs. One magazine of DAC film was used to record the commander's initial activities on the lunar surface as viewed from the lunar module window; the lunar module DAC was not used again until liftoff.
Panoramic Views. Features too large to record in single frames were documented in partial panoramas. The general setting of a station was routinely recorded in a complete 360° panorama. The 500-millimeter lens provided the capability to record distant features in single frames or in partial panoramas.
A view of the Taurus-Littrow landing site as seen from
the lunar module window before liftoff.
For the first time in an Apollo mission, the Antarctic continent was visible to and photographed by the orbiting astronauts. A spectacular group of 70-millimeter Hasselblad EL color photographs exposed in Earth orbit portrayed the sunlit portion of the Earth from the South Atlantic Ocean across Africa and the Indian Ocean to Australia. A portion of the lunar farside that had not been illuminated during the other J-series missions (Apollo 15 and 16) was in sunlight during the early revolution of the Apollo 17 spacecraft. The panoramic and mapping cameras were used to photograph a part of this area. In the panoramic camera, 1623 images were exposed, of which approximately 1580 were high-resolution photographs from lunar orbit. Of the 3298 mapping camera frames, approximately 2350 contain imagery of the lunar suface. A total of 1170 Hasselblad EL photographs were exposed from the command module (CM) and 2422 Hasselblad data camera (DC) photographs were exposed from the lunar module (LM) or — the case for the majority of the photos — on the lunar surface. Almost 380 Nikon 35-millimeter frames were exposed. Of the 12 magazines of 16-millimeter film exposed, four were used inside the LM and eight in the CM. Virtually for the first time on an Apollo mission, earthshine photographs provided usable imagery, including that of lunar surface areas where the crew reported seeing possible "flashes." Crew-option photographs included the "flash" areas, lunar surface color boundaries, areas with orange-colored strata, flows, and other features of geologic interest.