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Apollo 14 Lunar Module /ALSEP



The Apollo 14 Lunar Module (LM) "Antares" was the third crewed vehicle to land on the Moon. It carried two astronauts, Commander Alan B. Shepard Jr. and LM pilot Edgar D. Mitchell, the fifth and sixth men to walk on the Moon. Also included on the LM was the Apollo Lunar Surface Experiments Package (ALSEP) containing scientific experiments to be deployed and left on the lunar surface and other scientific and sample collection apparatus.

Mission Profile

The LM separated from the Command/Service Module (CSM) at 04:50:44 UT and landed at 09:18:11 UT (4:18:11 a.m. EST) on 5 February 1971 in the lunar highlands near the crater Fra Mauro at 3.64589 S latitude, 17.47194 W longitude (as determined from Lunar Reconnaissance Orbiter images, DE 421 mean Earth/polar rotation axis reference frame). The LM landed on the slope of a small depression, tilted at 8 degrees. Shepard and Mitchell made two moonwalk extra-vehicular activities (EVAs) totaling 9 hours, 23 minutes. The first EVA began at 14:42:13 UT and ended at 19:30:03 UT. During this first EVA the astronauts deployed the ALSEP and other experiments. During the second EVA, which took place from 8:11:15 to 12:45:56 UT on 6 February, the astronauts walked almost to the rim of nearby Cone crater, collecting samples along the traverse. At the end of this walk Shepard used a contingency sampler with a 6-iron connected to the end to hit two golf balls. The astronauts traversed a total of 3.45 km and collected 42.28 kg of lunar samples. The LM lifted off the Moon on 6 February at 18:48:42 UT after 33 hours 31 minutes on the lunar surface. After docking with the CSM (piloted by Stuart A. Roosa) at 20:35:53 UT, the LM was jettisoned at 22:48:00 UT and impacted the Moon at 3.42 S, 19.67 W, between the Apollo 12 and Apollo 14 seismic stations, at 00:45:25 UT on 7 February.

Lunar Module Spacecraft and Subsystems

The lunar module was a two-stage vehicle designed for space operations near and on the Moon. The spacecraft mass of 15264 kg was the total mass of the LM ascent and descent stages including propellants (fuel and oxidizer). The dry mass of the ascent stage was 2303 kg and it held 2370 kg of propellant. The descent stage dry mass (including stowed surface equipment) was 2237 kg and 8354 kg of propellant were onboard initially. The ascent and descent stages of the LM operated as a unit until staging, when the ascent stage functioned as a single spacecraft for rendezvous and docking with the command and service module (CSM). The descent stage comprised the lower part of the spacecraft and was an octagonal prism 4.2 meters across and 1.7 m thick. Four landing legs with round footpads were mounted on the sides of the descent stage and held the bottom of the stage 1.5 m above the surface. The distance between the ends of the footpads on opposite landing legs was 9.4 m. One of the legs had a small astronaut egress platform and ladder. A one meter long conical descent engine skirt protruded from the bottom of the stage. The descent stage contained the landing rocket, two tanks of aerozine 50 fuel, two tanks of nitrogen tetroxide oxidizer, water, oxygen and helium tanks and storage space for the lunar equipment and experiments, and in the case of Apollo 15, 16, and 17, the lunar rover. The descent stage served as a platform for launching the ascent stage and was left behind on the Moon.

The ascent stage was an irregularly shaped unit approximately 2.8 m high and 4.0 by 4.3 meters in width mounted on top of the descent stage. The ascent stage housed the astronauts in a pressurized crew compartment with a volume of 6.65 cubic meters. There was an ingress-egress hatch in one side and a docking hatch for connecting to the CSM on top. Also mounted along the top were a parabolic rendezvous radar antenna, a steerable parabolic S-band antenna, and 2 in-flight VHF antennas. Two triangular windows were above and to either side of the egress hatch and four thrust chamber assemblies were mounted around the sides. At the base of the assembly was the ascent engine. The stage also contained an aerozine 50 fuel and an oxidizer tank, and helium, liquid oxygen, gaseous oxygen, and reaction control fuel tanks. There were no seats in the LM. A control console was mounted in the front of the crew compartment above the ingress-egress hatch and between the windows and two more control panels mounted on the side walls. The ascent stage was launched from the Moon at the end of lunar surface operations and returned the astronauts to the CSM.

The descent engine was a deep-throttling ablative rocket with a maximum thrust of about 45,000 N mounted on a gimbal ring in the center of the descent stage. The ascent engine was a fixed, constant-thrust rocket with a thrust of about 15,000 N. Maneuvering was achieved via the reaction control system, which consisted of the four thrust modules, each one composed of four 450 N thrust chambers and nozzles pointing in different directions. Telemetry, TV, voice, and range communications with Earth were all via the S-band antenna. VHF was used for communications between the astronauts and the LM, and the LM and orbiting CSM. There were redundant tranceivers and equipment for both S-band and VHF. An environmental control system recycled oxygen and maintained temperature in the electronics and cabin. Power was provided by 6 silver-zinc batteries. Guidance and navigation control were provided by a radar ranging system, an inertial measurement unit consisting of gyroscopes and accelerometers, and the Apollo guidance computer.

Apollo Lunar Surface Experiments Package (ALSEP)

The Apollo Lunar Surface Experiments Package (ALSEP) consisted of a set of scientific instruments emplaced at the landing site by the astronauts. The instruments were arrayed around a central station which supplied power to run the instruments and communications so data collected by the experiments could be relayed to Earth. The central station was a 25 kg box with a stowed volume of 34,800 cubic cm. Thermal control was achieved by passive elements (insulation, reflectors, thermal coatings) as well as power dissipation resistors and heaters. Communications with Earth were achieved through a 58 cm long, 3.8 cm diameter modified axial-helical antenna mounted on top of the central station and pointed towards Earth by the astronauts. Transmitters, receivers, data processors and multiplexers were housed within the central station. Data collected from the instruments were converted into a telemetry format and transmitted to Earth. The ALSEP system and instruments were controlled by commands from Earth. The uplink frequency for all Apollo mission ALSEP's was 2119 MHz, the downlink frequency for the Apollo 14 ALSEP was 2279.5 MHz.

Radioisotope Thermoelectric Generator (RTG)

The SNAP-27 model RTG produced the power to run the ALSEP operations. The generator consisted of a 46 cm high central cylinder and eight radiating rectangular fins with a total tip-to-tip diameter of 40 cm. The central cylinder had a thinner concentric inner cylinder inside, and the two cylinders were attached along their surfaces by 442 spring-loaded lead-telluride thermoelectric couples mounted radially along the length of the cylinders. The generator assembly had a total mass of 17 kg. The power source was an approximately 4 kg fuel capsule in the shape of a long rod which contained plutonium-238 and was placed in the inner cylinder of the RTG by the astronauts on deployment. Plutonium-238 decays with a half-life of 89.6 years and produces heat. This heat would conduct from the inner cylinder to the outer via the thermocouples which would convert the heat directly to electrical power. Excess heat on the outer cylinder would be radiated to space by the fins. The RTG produced approximately 70 W DC at 16 V. (63.5 W after one year.) The electricity was routed through a cable to a power conditioning unit and a power distribution unit in the central station to supply the correct voltage and power to each instrument.

ALSEP Scientific Instruments

All ALSEP instruments were deployed on the surface by the astronauts and attached to the central station by cables. The Apollo 14 ALSEP instruments consisted of: (1) a passive seismometer, designed to measure seismic activity and physical properties of the lunar crust and interior; (2) an active seismometer to study the physical properties of lunar surface and subsurface materials and the structure of the local near-surface layers; (3) a suprathermal ion detector, designed to measure the flux composition, energy, and velocity of low-energy positive ions; (4) a charged particle lunar environment experiment, designed to measure particle energies of solar protons and electrons that reach the lunar surface; (5) a cold cathode ion gauge, designed to measure the atmosphere and any variations with time or solar activity such atmosphere may have; and (6) a lunar dust detector, to measure dust accumulation, radiation damage to solar cells, and reflected infrared energy and temperatures. The central station, located at 3.6440 S latitude, 17.4775 W longitude, was turned on at 17:23 UT on 5 February 1971. Signal was lost on 1 March 1975 and regained on 5 March 1975. Command uplink capability was lost on 18 January 1976 and regained on 19 February 1976. Although telemetry and data downlink continued over most of this time, operation of many experiments was affected because commands could not be sent. Loss and reacquisition of signal happened sporadically until termination of the ALSEP experiment. Loss-reacquisition of signal occurred in 1976 on 17 March - 20 May, 8 June - 10 June, 9 October - 12 November and in 1977 on 30 July - 4 August. The Apollo 14 ALSEP was shut down along with the other ALSEP stations on 30 September 1977.

Alternate Names

  • 04905
  • Antares
  • Apollo 14 LM/ALSEP
  • Apollo 14 Lunar Surface Experiments Package
  • Apollo 14C
  • Apollo14ALSEP
  • LEM 14
  • LM-8

Facts in Brief

Launch Date: 1971-01-31
Launch Vehicle: Saturn 5
Launch Site: Cape Canaveral, United States
Mass: 15264 kg

Funding Agencies

  • NASA-Office of Manned Space Flight (United States)
  • NASA-Office of Space Science (United States)


  • Planetary Science
  • Space Physics
  • Human Crew
  • Earth Science

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Mr. Wilbert F. EichelmanProject ManagerNASA Johnson Space Center
Dr. John B. HanleyProgram ScientistNASA Headquarters
Mr. Floyd I. RobersonProgram ManagerNASA Headquarters

Selected References

  • Apollo 14 preliminary science report, NASA, SP-272, Wash., D.C., June 1971.
  • Davies, M. E., and T. R. Colvin, Lunar coordinates in the regions of the Apollo landers, J. Geophys. Res., 105, No. E8, 20277-20280, Aug. 2000.
Diagram of Apollo 11 Lunar Module

Diagram of the Apollo Lunar Module. (Courtesy of NASA History Office.)

Other Sources of Apollo 14 Information at NSSDCA

Apollo 14 Command Module
Moon Trees - Trees planted from seeds carried in lunar orbit on Apollo 14
Apollo 14 Page

Other Sources of Apollo Information at NSSDCA

Apollo landing sites and ALSEP and LRRR locations - and information on the modified DMA/603 control network
Apollo Page
Lunar Science Page

Related Information at NSSDCA

Moon Page

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