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Instrument Host Overview
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Apollo 17 Command and Service Module (CSM) was the sixth and last
crewed vehicle to orbit on the Moon as part of NASA's Apollo program.
It was piloted by astronaut Ronald E. Evans.
Spacecraft and Subsystems
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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
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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
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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 CSM and its experiments, see the Apollo
17 Preliminary Science Report (1973) [APOLLO17A1973].
This description was provided by the NASA Space Science Data Coordinated
Archive (NSSDCA).
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