Apollo 17 Command and Service Module Instrument Host Overview ======================== Apollo 17 Command and Service Module (CSM) was the sixth and last crewed vehicle to orbit the Moon as part of NASA's Apollo program. It was piloted by astronaut Ronald E. Evans. Spacecraft and Subsystems ------------------------- As the name implies, the Command and Service Module (CSM) was comprised of two distinct units: the Command Module (CM), which housed the crew, spacecraft operations systems, and re-entry equipment, and the Service Module (SM) which carried most of the consumables (oxygen, water, helium, fuel cells, and fuel) and the main propulsion system. The total length of the two modules attached was 11.0 meters with a maximum diameter of 3.9 meters. Block II CSM's were used for all the crewed Apollo missions. Apollo 17 was the third of the Apollo J-series spacecraft. The launch mass, including propellants and expendables, of the Apollo 17 CSM was 30,320 kg of which the Command Module (CM-114) had a mass of 5960 kg and the Service Module (SM-114) 24,360 kg. The Apollo 17 CM capsule 'America' is on display at the Johnson Space Center in Houston, Texas. Telecommunications included voice, television, data, and tracking and ranging subsystems for communications between astronauts, CM, LM, and Earth. Voice contact was provided by an S-band uplink and downlink system. Tracking was done through a unified S-band transponder. A high gain steerable S-band antenna consisting of four 79-cm diameter parabolic dishes was mounted on a folding boom at the aft end of the SM. Two VHF scimitar antennas were also mounted on the SM. There was also a VHF recovery beacon mounted in the CM. The CSM environmental control system regulated cabin atmosphere, pressure, temperature, carbon dioxide, odors, particles, and ventilation and controlled the temperature range of the electronic equipment. Command Module -------------- The CM was a conical pressure vessel with a maximum diameter of 3.9 meters at its base and a height of 3.65 meters. It was made of an aluminum honeycomb sandwich bonded between sheet aluminum alloy. The base of the CM consisted of a heat shield made of brazed stainless steel honeycomb filled with a phenolic epoxy resin as an ablative material and varied in thickness from 1.8 to 6.9 centimeters. At the tip of the cone was a hatch and docking assembly designed to mate with the lunar module. The CM was divided into three compartments. The forward compartment in the nose of the cone held the three 25.4 meters diameter main parachutes, two 5 meter drogue parachutes, and pilot mortar chutes for Earth landing. The aft compartment was situated around the base of the CM and contained propellant tanks, reaction control engines, wiring, and plumbing. The crew compartment comprised most of the volume of the CM, approximately 6.17 cubic meters of space. Three astronaut couches were lined up facing forward in the center of the compartment. A large access hatch was situated above the center couch. A short access tunnel led to the docking hatch in the CM nose. The crew compartment held the controls, displays, navigation equipment and other systems used by the astronauts. The CM had five windows: one in the access hatch, one next to each astronaut in the two outer seats, and two forward-facing rendezvous windows. Five silver/zinc-oxide batteries provided power after the CM and SM detached, three for re-entry and after landing and two for vehicle separation and parachute deployment. The CM had twelve 420-Newton nitrogen tetroxide/hydrazine reaction control thrusters. The CM provided the re-entry capability at the end of the mission after separation from the Service Module. Service Module -------------- The SM was a cylinder 3.9 meters in diameter and 7.6 meters long which was attached to the back of the CM. The outer skin of the SM was formed of 2.5 cm thick aluminum honeycomb panels. The interior was divided by milled aluminum radial beams into six sections around a central cylinder. At the back of the SM mounted in the central cylinder was a gimbal mounted re-startable hypergolic liquid propellant 91,000 Newton engine and cone shaped engine nozzle. Attitude control was provided by four identical banks of four 450 Newton reaction control thrusters each spaced 90 degrees apart around the forward part of the SM. The six sections of the SM held three 31-cell hydrogen oxygen fuel cells which provided 28 volts, an auxiliary battery, three cryogenic oxygen and three cryogenic hydrogen tanks, four tanks for the main propulsion engine, two for fuel and two for oxidizer, the subsystems the main propulsion unit, and a Scientific Instrument Module (SIM) bay which held a package of science instruments and cameras to be operated from lunar orbit. Two helium tanks were mounted in the central cylinder. Electrical power system radiators were at the top of the cylinder and environmental control radiator panels spaced around the bottom. Scientific Experiments ---------------------- The following scientific experiments were performed on board the Apollo 17 Command and Service Module: - The Handheld Photography Experiment included Hasselblad and Maurer cameras that were used (1) to obtain photographs of the transposition, docking, lunar module ejection maneuver, and LM rendezvous sequence from both the command and lunar modules, (2) to obtain photographs of the lunar ground track and of future landing sites, (3) to record the operational activities of the crew, (4) to obtain long-distance earth and lunar photographs for areas of scientific interest, and (5) to obtain photos of lunar surface features and of the activities of the astronauts after their landing on the Moon. - The Panoramic Photography Experiment obtained high-resolution panoramic photographs with stereoscopic and monoscopic coverage of the lunar surface using a panoramic camera. - The Metric Photography Experiment obtained high-quality metric photographs of the lunar surface and stellar photographs exposed simultaneously with the metric photographs. - The Mapping Camera Aspect Stellar Photography was part of the mapping camera subsystem, which provided cartographic pointing references for the metric camera through the use of the star field photographed. - The Laser Altimeter Experiment obtained data on the altitude of the CSM above the lunar surface to support mapping and panoramic camera photography, to provide altitude data for other orbital experiments, and to relate lunar topographical features for a better definition of lunar shape. - The Far-Ultraviolet Spectrometer Experiment measured from orbit the composition of the lunar atmosphere in a spectral range from 1180 to 1680 Angstrom. Additional observations were made of the lunar surface, zodiacal light, solar atmosphere emissions, earth emissions, and galactic and stellar emissions. - The Infrared Scanning Radiometer mapped from orbit the thermal emission from the lunar surface to produce a high-resolution surface temperature map. - The Lunar Sounder Experiment, used synthetic aperture radar to (1) map the subsurface electrical conductivity structure of the upper kilometer of the lunar crust to infer geological structure, (2) make surface profiles to determine lunar topographic variations, (3) produce surface imaging, and (4) measure galactic electromagnetic radiation in the lunar environment. - The S-Band Transponder Experiment measured the lunar gravitational field by observing the dynamical motion of the spacecraft in free fall orbits to provide information about the distribution of lunar mass. - The Window Meteoroid Detector Experiment used the CM heat shield window surfaces (fused silica) to obtain information about the flux of meteoroids with masses of 1 nanogram or less. About 0.4 square meters of the window surfaces were used as meteoroid impact detectors. - The Biological Cosmic Ray Experiment (BIOCORE) had the primary scientific objective of determining if heavy cosmic ray particles (stripped nuclei) injure the brain, eyes, skin, and other tissues. The experiment consisted of a group of pocket mice with cosmic ray detectors planted under their scalps which were flown aboard the CM in a special container. - The Biostack Experiment used a hermetically sealed aluminum container containing a series of monolayers of selected biologic material to study the effects of high-energy/high-Z particles on a broad spectrum of biologic systems from the molecular to the highly organized and developed forms of life. - The Heat Flow and Convection experiment was an engineering test performed on board the CM to measure and observe the behavior of fluid flowing in the absence of gravity. - The Light Flashes Experiment studied light flashes seen by the crew that are related to charged particles in space. For more information about the experiments, see the Apollo 17 Preliminary Science Report (1973). References ========== Apollo 17 Preliminary Science Report, NASA SP-330, published by NASA, Washington, D.C., 1973.