Apollo 17 Command and Service Module (CSM)

Description

Apollo 17 was the sixth and last Apollo mission in which humans walked on the lunar surface. On 11 December 1972 two astronauts (Commander Eugene A. Cernan and LM pilot Harrison H. Schmitt, the first scientist on the Moon) landed in the Taurus-Littrow region of the Moon in the Lunar Module (LM) while the Command and Service Module (CSM) (with CM pilot Ronald E. Evans) continued in lunar orbit. During their stay on the Moon, the astronauts set up scientific experiments, took photographs, and collected lunar samples. The LM took off from the Moon on 14 December and the astronauts returned to Earth on 19 December.

Mission Profile

Apollo 17 lifted off at 05:33:00 UT (12:33:00 a.m. EST) on 7 December 1972 after a 2 hour, 40 minute delay due to a malfunction of a launch sequencer. Launch was on Saturn V SA-512 from Pad 39A at Kennedy Space Center and was the first nighttime launch of an Apollo. The spacecraft began Earth parking orbit at 05:44:53 UT and translunar injection took place at 08:45:37 UT. The CSM separated from the S-IVB at 09:15:29 UT and CSM-LM docking took place at 09:29:45 UT. The S-IVB was released at 10:18 UT into a lunar impact trajectory. (It impacted the lunar surface on 10 December at 20:32:42.3 UT at 4.21 S, 12.31 W with a velocity of 2.55 km/s at a 55 degree angle from the horizontal.) A single mid-course correction requiring a 1.6 second burn of the Service Propulsion System (SPS) was made at 17:03:00 UT on 8 December. On December 10 at 15:05:40 UT the SIM bay door was jettisoned and a 398 second burn of the SPS was initiated at 19:47:23 UT to insert Apollo 17 into lunar orbit. Approximately 4 hours 20 minutes later another maneuver lowered the orbit to a perilune of 28 km. At 14:35 UT on 11 December Cernan and Schmitt entered the LM.

The LM separated from the CSM at 17:20:56 UT on 11 December 1972 and reduced its orbit to 11.5 km perilune at 18:55:42 UT. The descent burn took place at 19:43 UT and the LM landed at 19:54:57 UT on the southeastern rim of Mare Serenitatis in a valley at Taurus-Littrow, at 20.2 N, 30.8 E. Cernan and Schmitt made three moonwalk extra-vehicular activities (EVAs) totaling 22 hours, 4 minutes. During this time they covered 30 km using the Lunar Roving Vehicle, collected 110.52 kg of lunar samples, took photographs, and set up the ALSEP and performed other scientific experiments. Evans performed experiments from orbit in the CSM during this time.

The LM lifted off from the Moon at 22:54:37 UT on 14 December after 75 hours on the lunar surface. After the LM docked with the CSM at 01:10:15 UT on 15 December the lunar samples and other equipment were transferred from the LM and the LM was jettisoned at 04:51:31 UT. The LM impacted the Moon at 06:50:20.8 UT at 19.96 N, 30.50 E, approximately 15 km from the Apollo 17 landing site, with an estimated impact velocity of 1.67 km/s at an angle ~4.9 degrees from horizontal. After another 1 1/2 days in lunar orbit, transearth injection took place at 23:35:09 UT on 16 December. On 17 December at 20:27 UT Evans began a cislunar spacewalk EVA consisting of three trips to the SM SIM bay to collect camera and lunar sounder film over a period of 67 minutes. The CM and SM separated at 18:56:49 UT on 19 December. Apollo 17 splashed down in the Pacific Ocean on 19 December 1972 at 19:24:59 UT (2:24:59 p.m. EST) after a mission elapsed time of 301 hrs, 51 mins, 59 secs. The splashdown point was 17 deg 53 min S, 166 deg 7 min W, 350 nautical miles SE of the Samoan Islands and 6.5 km (4 mi) from the recovery ship USS Ticonderoga.

Performance of the spacecraft, the third of the Apollo J-series missions, was excellent for all aspects of the mission. The primary mission goals of investigating the lunar surface and environment in the Taurus-Littrow region, emplacing and activating surface experiments, performing experiments in lunar orbit, obtaining and returning lunar surface samples, and enhancing the capability for future astronaut lunar exploration were achieved. Cernan, 38, was a Navy captain with two previous spaceflights (Gemini 9, Apollo 10), Evans, 39, was a Navy commander making his first spaceflight, and Schmitt, 37, was a civilian also making his first spaceflight. The backup crew for this mission was John Young, Stuart Roosa, and Charles Duke. The Apollo 17 command module capsule "America" is on display at the Johnson Space Center in Houston, Texas.

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 CSM mass of 30,320 kg was the launch mass including propellants and expendables, of this the Command Module (CM-114) had a mass of 5960 kg and the Service Module (SM-114) 24,360 kg.

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 m at its base and a height of 3.65 m. It was made of an aluminum honeycomb sandwhich 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 cm. 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 m diameter main parachutes, two 5 m 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 N 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.

The SM was a cylinder 3.9 meters in diameter and 7.6 m 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 N engine and cone shaped engine nozzle. Attitude control was provided by four identical banks of four 450 N 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.

Apollo Program

The Apollo program included a large number of uncrewed test missions and 12 crewed missions: three Earth orbiting missions (Apollo 7, 9 and Apollo-Soyuz), two lunar orbiting missions (Apollo 8 and 10), a lunar swingby (Apollo 13), and six Moon landing missions (Apollo 11, 12, 14, 15, 16, and 17). Two astronauts from each of these six missions walked on the Moon (Neil Armstrong, Edwin Aldrin, Charles Conrad, Alan Bean, Alan Shepard, Edgar Mitchell, David Scott, James Irwin, John Young, Charles Duke, Gene Cernan, and Harrison Schmitt), the only humans to have set foot on another solar system body. Total funding for the Apollo program was approximately $20,443,600,000.a

For information on the Lunar Module and details of activities on the lunar surface, see:

http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1972-096C