PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM LABEL_REVISION_NOTE = "20090629, L. Gaddis - Initial Version 20101001 C. Isbell - Post Review" OBJECT = INSTRUMENT INSTRUMENT_HOST_ID = "LO5" INSTRUMENT_ID = {"80MM_FLC","610MM_FLC"} OBJECT = INSTRUMENT_INFORMATION INSTRUMENT_NAME = {"80-MM FOCAL LENGTH CAMERA", "610-MM FOCAL LENGTH CAMERA"} INSTRUMENT_TYPE = "DUAL LENS CAMERA" INSTRUMENT_DESC = " LUNAR ORBITER V PHOTOGRAPHIC SYSTEM OVERVIEW ============================================== Much of the information in this document was abstracted from Kosofsky and El- Baz, 1970; Hansen, 1970; and Bowker and Hughes, 1971]. See references cited for more detail. The Lunar Orbiter photographic system included the spacecraft's photographic subsystem; the ground reconstruction electronics (GRE); and the communications system. The five Lunar Orbiter missions used a dual-lens camera system a 610-mm narrow angle high-resolution (HR) lens and an 80-mm wide-angle medium resolution (MR) lens [e.g., Boeing Company, 1967, 1968a, b; Hansen, 1970; Kosofsky and El-Baz, 1970; Bowker and Hughes, 1971; Byers, 1977]. Both lenses placed their frame exposures on a single roll of 70 mm film. The axes of the two cameras were coincident so the areas imaged in the HR frames were centered within the MR frame areas. The telephoto lens provided coverage equivalent to 1 meter from an altitude of 46 kilometers and the wide-angle lens an 8 meter object from the same altitude. The photography was conducted as planned, except for the addition of the Earth photo and a slight relocation of some photo sites. A total of 426 telephoto and wide-angle photographs (213 dual exposures) were taken during 50 sequences on the nearside and 25 from near apolune, 23 of which were of the farside areas. The remaining two sequences were used for the Earth photo and a blank film-set exposure. At one point, the spacecraft was maneuvered to reflect sunlight from its solar panels and underside mirrors and the reflected rays were photographed by telescopes on Earth. Scientific Objectives --------------------- The primary objective of the five Lunar Orbiter missions was to locate smooth, level areas on the Moon's nearside and to confirm their suitability as manned landing sites for the Apollo program. This required photographic coverage at a ground resolution of 1 meter within 5o of the equator between longitudes 45oE and 45oW. This objective was met by the first three missions and so Missions IV and V were to obtain scientifically interesting photographs of the near and far side of the moon. Like Lunar Orbiter IV, LO V was also placed in a high polar orbit with an inclination of 85o. The mission completed the photo requirements for the candidate Apollo sites and took photographs of interesting features on the near and far side of the Moon. The secondary objectives were to provide precision trajectory information to better define the lunar gravitational field, measurements of micrometeoroid flux and radiation dose, and a spacecraft to be tracked in lunar orbit to evaluate its effectiveness for Apollo. THE LUNAR ORBITER V PHOTOGRAPHIC SUBSYSTEM ============================================ The photographic subsystem was designed to photograph the lunar surface, process the exposed film, scan the processed film with a flying spot scanner and provide video signals to the communications subsystem for transmission to Earth [e.g., Beeler and Michlovitz, 1969; Boeing Company, 1968a, b; Hansen, 1970; Anderson and Miller, 1971].. The system comprised a dual camera, a film processing unit, a readout scanner, and film-handling apparatus. The photo subsystem simultaneously exposes two pictures at a time, processes the film and converts the information to an electrical signal for transmission to Earth. No major changes were made in this subsystem following Mission III [e.g., Boeing Company, 1968b]. Dual Cameras ------------ The two cameras, one with a high resolution (HR) lens and one with a medium resolution (MR) lens, operated simultaneously, placing two discrete frame exposures on a common roll of 70-mm film [e.g., Boeing Company, 1968a]. The high-resolution (H) frame was exposed through a 610-mm narrow-angle lens and a focal plane shutter. The medium-resolution (M) frame was exposed through an 80-mm wide-angle lens and a between-the-lens shutter. A neutral-density filter having an optical density of 0.18 was attached to the 80-mm lens to balance its transmissivity with that of the 610-mm lens. The 80-mm focal- length lens provided an angular coverage of 44.4o by 38o; the 610-mm focal- length lens had an angular coverage of 20.4o by 5.16o. The two camera axes were coincident so that coverage of the H-frame was centered within the coverage of the M-frame. Each camera operated at a fixed f/5.6 lens aperture, at shutter speeds of either 1/25, 1/50, or 1/100 second. Exposure times were recorded in digital form on the film alongside the M-frames. Image-motion compensation (IMC) was provided to minimize smear. An electric- optical sensor viewed the lunar surface through a portion of the 610-mm lens to determine the spacecraft's velocity to height (V/H) ratio. This was used for direct drive of the camera platens and film at the proper rate to ensure IMC during exposure and also for controlling the spacing of exposures during multiple exposure sequences. Photographs could be taken as single frames or sequences of 4, 8 or 16 frames. Multiple frame sequences could be taken in the fast mode, which obtained contiguous telephoto coverage with 87% forward overlap of wide-angle coverage - or in the slow mode, which provided 50% forward overlap of wide- angle coverage). Unlike previous missions, many of the primary nearside sites were photographed as single-frame exposures using near-vertical, conventional oblique, westerly oblique, and convergent telephoto stereo methods. A total of 213 dual-frame exposures were taken in a single fame, four- or eight-frame fast sequences, or four-frame slow-mode sequences during 82 orbits. All planned photography was accomplished; all of these photos were processed and read out except the last wide-angle exposure. Camera operation was completely satisfactory [Boeing Company, 1968a, b]. Photo quality was somewhat degraded in certain frames by the occurrence of a defect in processing and by the occasional intermittent video dropout. Calibration ----------- Tests and calibrations performed on the photographic subsystem included lens- film characteristics, exposure calibration and control, image motion compensation, camera alignment, readout quality, and photogrammetric distortion calibration of the 80-mm camera. Film ---- The Kodak special high definition 70-mm film aerial film, type SO-243, with a recording capability of 450 lines/mm met the resolution requirement of approximately 76 lines/mm and low enough speed to make it relatively insensitive to space environment radiation. Vacuum platens held the film during exposure. A short roll of Bimat resulted in the failure to completely process the last two wide-angle exposures and the film leader parted during the final stages of winding the film on the supply spool after final readout, thereby preventing any additional photo readouts during the extended mission. Camera Film Advance -------------------- The average camera film advance was 11.690+-0.117 inches or as 130 plus 3 or minus 2 edge data numbers. Film advances throughout the mission were slightly long and a few were out of tolerance and the actual film advance was 11.81 inches per frame, amounting to an addition 2.11 feet of film and requiring an equal amount for Bimat processing. Filters ------- The Mission V photo subsystem was equipped with a 0.21 neutral density filter in front of the 80-mm lens to nearly equalize the light transmission characteristics of the two lens systems because of a differential in transmissivity between the 610-mm telephoto optics and the 80-mm wide-angle lens. However, it did not completely balance exposure of the frames. While the wide-angle frames received slightly more exposure, the differential mostly did not have serious consequences in photographic quality. Exposure -------- Exposure control for nearside sites was accomplished by scheduling photography at times when Sun angle was in the acceptable range without undesirable camera tilt. Exposure was also controlled by shutter speed selection (0.04, 0.02 or 0.01 second) with the lens aperture fixed at f/5.6. Shutter speed selection was made on the basis of predicted spacecraft film densities computed by the Photo Quality Prediction program. Exposures were satisfactory for both wide-angle and telephoto frames [Boeing Company, 1968a, b]. The sites were all within mare areas with flat topography and few large features to present photographic problems. Small-scale features presented luminance extremes with hard shadow on one side and very bright slopes on the opposite side. However, while exposure varies across the frame, surface detail is present in most or all of the frame. Because of the topographic characteristics of the lunar terrain, the effects of the lunar photometric function, and photo subsystem limitations, almost all photographs include at least some areas of either under or over exposure due to the extreme luminance range of the surface. Resolution ---------- The requirement for resolution for the Lunar Orbiter missions was that the photograph could detect a 1-meter object with the telephoto lens and an 8- meter object with the wide-angle lens from an altitude of 46 kilometers. This required a resolution of 76 lines per millimeter on the spacecraft film or 10 lines per millimeter on the GRE record. The resolution requirement was equivalent to detection of objects with images spanning four scan lines. Ground resolution was proportional to the line-of-sight distance in which the size of an object on the ground whose image spans four scan lines on the telephoto frame was given for a range of distances between camera and object [Boeing Company, 1968a, b]. Resolution of both wide-angle and telephoto photographs equaled or bettered that of previous missions. Resolution of between three and four scan lines was observed near the center of the frame consistently on nearly all frames. Resolution was uniformly good with few exceptions. PATTERNS OF PHOTOGRAPHIC COVERAGE ================================= To expedite planning, initial selection of Mission 5 sites was made prior to the availability of Mission 4 photographic data. When this data became available for additional evaluation of the initial site selections, a few sites were deleted and the location of others was modified to obtain more significant data. Photo sites included candidate Apollo landing sites, Apollo applications program sites, Surveyor landing sites, and scientifically interesting sites. In all, 69 photo sites were selected, 45 on the nearside, and 24 on the farside. The perilune altitude was about twice that of the first three missions the resolution for images would be 2 m for the telephoto lens and 16 m for the wide-angle lens, which was chosen to enable stereo coverage without excessive camera tilt. The higher altitude also allowed near-equatorial sites to be photographed with half the number of frames as for the first three missions, so a larger number of sides could be photographed [Boeing Company, 1968a, b]. Film Processing --------------- Film procession for Mission V photography was generally comparable with that of previous missions. Prior to being placed onboard the spacecraft, the photographic film was soaked in a monobath processing solution to develop the exposed portions to a negative image, with exposed with strip numbers, a nine-level grayscale bar, resolving power chart, and reseau marks. After exposure, film-processing took place on board the spacecraft by the Kodak Bimat diffusion transfer technique. In this process, the film is temporarily laminated to the Bimat and carried around a temperature-controlled drum while in contact. During the lamination period, a single solution processing liquid, absorbed in the Bimat emulsion, diffused onto the SO-243 emulsion to simultaneously develop and fix the photographic image. The SO-243 and Bimat were delaminated upon leaving the processor drum. The used Bimat was collected onto a takeup reel and the slightly moist SO243 passed through a heated dryer. The moisture was absorbed by a desiccant [Boeing Company, 1968a, b]. Film Readout ------------ Optical density variations of the negative photographic image were converted into analog electrical signals by the photo-video chain for transmission to Earth. A 6.5 micron diameter image of an oscillating spot of light produced on the rotating anode of a line-scan tube was focused on the photographic film in the readout gate. The image moved longitudinally on the film a distance of 2.67 mm, and the scanner lens moved at right angles to the film following each scan. The result was a 'framelet' having a raster of 16,359 lines across 57 mm of the 70-mm width. Following completion of one framelet, the film was moved 2.54 mm to begin scan of the next, moving across the film in the opposite direction. The light passing through the film modulated by the image density was sensed by a photomultiplier tube through associated light collection optics [Boeing Company, 1968a, b]. Readout of the photographs was accomplished and was of satisfactory quality and extended readout sequences were accomplished during the final readout. Priority readout was started during Orbit 5 and a total of 86 priority readouts were completed during the photo-taking portion of the mission. The duration of priority readouts ranged from a minimum of 28 to a maximum of 440 framelets. Readout varied in duration from 5 minutes to 2.97 hours. Covering all of the Mission V photographs required 61 final readout sequences with the longest sequence containing four frames. The Bimat roll was short and all of the Bimat moved through the processor approximately 5 minutes prior to the execution of the 'Bimat cut' command as indicated by a 'Bimat clear' signal. As a result one wide-angle exposure of an eight-frame sequence was degraded and the final exposure was not processed, resulting in a loss of about 7% and degradation of an additional 7% of the wide-angle site coverage. All other photos were completely processed. Final readout was initiated on 1967-08-19 at 4:30 GMT and continued continuously. Readout of the priority and final phases were combined. Final readout continued until 1967-08-27 at 05:38 GMT [Boeing Company, 1968a, b]. After final readout was completed, it was discovered that the film leader had torn. All photo system operations were then terminated. TRANSMISSION AND RECONSTRUCTION OF PHOTOGRAPHS ============================================== The original photograph was transmitted to Earth as analog data. Photographic prints from the film strips were hand mosaicked into sub-frame (for HR data) and full-frame (for MR data) views and widely distributed. The resulting analog signal was amplified, timing and synchronization pulses were added to form the composite video signal, and the signal was transmitted to Earth by the spacecraft video transmitter [Boeing Company, 1968a, b]. The video data coming from the photographic subsystem occupied a frequency spectrum from 0 to 230 kilohertz. This signal was modulated on a 310-kHz subcarrier (single sideband, suppressed carrier). The video signal, telemetry signals, and a 38.75-kHz pilot tone were summed, and the resulting composite signal phase- modulated the S-band (2295-MHz) carrier. A 10-watt traveling-wave tube amplifier and a 92-cm parabolic antenna transmitted the signal to Earth, where it was received at one of the three deep space stations (DSS) [e.g., Bundick et al., 1965]. The 10-MHz intermediate frequency of the DSS receiver, containing the composite signal, was recorded on magnetic tape for permanent storage. At the same time, it was passed to the ground communications equipment which recovered the telemetry and video. The video signal was recorded on magnetic tape and that record was forwarded to the Langley Research Center where it was used in preparing GRE records where it was converted into an intensity modulated line on the face of a cathode-ray tube. Video data was not present on from three to six successive scan lines at irregular intervals during readout, although after each video dropout cane a gradual return to normal levels. Each dropout appeared as a thin white line on the GRE film and obscured very little of the photo data. All reassembly of Mission V photographs was done by hand at both Langley Research Center and the Army Map Service, although the procedure by which positive paper prints were prepared was different. Langley prepared GRE film records from playback of the magnetic tape video record then films were hand reassembled to create negatives for print production. The Army Map Service used a negative copy of the prime GRE record made by Eastman Kodak to create a positive contact, which was then cut into individual framelets and mounted on a transparent backing in the correct sequence. The framelets were made into a film negative and then made into paper prints [Boeing Company, 1968a, b]. GRE 35-mm film was printed on Type 5234 Eastman Fine-Grain Duplicating Film. The photo subsystem of Lunar Orbiter V produced the best quality photographs of the five missions and only one of the 426 photographs taken was not recovered [Boeing Company, 1968a, b]." OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "ANDERSON&MILLER1971" END_OBJECT = INSTRUMENT_REFERENCE_INFO OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "BEELER&MICHLOVITZ1969" END_OBJECT = INSTRUMENT_REFERENCE_INFO OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "BOEINGCO1967" END_OBJECT = INSTRUMENT_REFERENCE_INFO OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "BOEINGCO1968A" END_OBJECT = INSTRUMENT_REFERENCE_INFO OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "BOEINGCO1968B" END_OBJECT = INSTRUMENT_REFERENCE_INFO OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "BOWKER&HUGHES1971" END_OBJECT = INSTRUMENT_REFERENCE_INFO OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "BUNDICKETAL1965" END_OBJECT = INSTRUMENT_REFERENCE_INFO OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "BYERS1977" END_OBJECT = INSTRUMENT_REFERENCE_INFO OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "HANSEN1970" END_OBJECT = INSTRUMENT_REFERENCE_INFO OBJECT = INSTRUMENT_REFERENCE_INFO REFERENCE_KEY_ID = "KOSOFSKY&ELBAZ1970" END_OBJECT = INSTRUMENT_REFERENCE_INFO END_OBJECT = INSTRUMENT END