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 3.6453 S latitude, 17.4714 W longitude (IAU Mean Earth Polar Axis coordinate system). 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 15,264 kg was the mass of the LM including astronauts, expendables, and 11,010 kg of propellants. The fully fueled mass of the ascent stage was 4943 kg and the descent stage 10,334 kg. 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 and shut down along with the other ALSEP stations on 30 September 1977.

阿波罗14号月球模块（LM）“安塔瑞斯”是第三艘成功登陆月球的载人航天器。它搭载了两位宇航员，指挥官艾伦·B·谢泼德少将和月球模块飞行员埃德加·D·米切尔，他们是第五位和第六位踏上月球的人类。月球模块上还装载了阿波罗月球表面实验包（ALSEP），其中包含将在月球表面部署并留下的科学实验设备以及其他科学和样本收集装置。

任务概况

月球模块于1971年2月5日04:50:44 UTC与指令/服务模块（CSM）分离，并在09:18:11 UTC（美国东部标准时间凌晨4:18:11）在月球高地、Fra Mauro陨石坑附近登陆，纬度为3.6453 S，经度为17.4714 W（IAU平均地球极轴坐标系）。月球模块在小型洼地的斜坡上降落，倾斜角度为8度。谢泼德和米切尔进行了两次共计9小时23分钟的月面行走。第一次月面行走于14:42:13 UTC开始，至19:30:03 UTC结束。在这第一次月面行走中，宇航员部署了ALSEP和其他实验。在第二次月面行走中，该次行走发生在2月6日的08:11:15至12:45:56 UTC之间，宇航员几乎走到了附近圆锥形陨石坑的边缘，沿途收集样本。在这次行走的最后阶段，谢泼德使用了一个配备6号铁杆的应急采样器击打了两个高尔夫球。宇航员总共行走了3.45公里，收集了42.28公斤的月球样本。月球模块于2月6日18:48:42 UTC从月球升起，月球表面停留时间为33小时31分钟。在20:35:53 UTC与由斯图尔特·A·罗莎驾驶的CSM对接后，月球模块于22:48:00 UTC被抛弃，并在2月7日00:45:25 UTC在3.42 S，19.67 W（介于阿波罗12号和阿波罗14号地震站之间）撞击月球。

月球模块航天器和子系统

月球模块是一种双级航天器，专为月球附近的太空作业设计。航天器总质量为15,264公斤，包括宇航员、消耗品和11,010公斤推进剂。上升级完全加注的质量为4943公斤，下降级为10,334公斤。上升级和下降级在级间分离之前作为一个整体运行，级间分离时上升级作为单独的航天器进行与指令和服务模块（CSM）的会合和对接。下降级构成了航天器的下部，是一个直径4.2米、厚1.7米的八边形棱柱。四个带有圆形脚垫的着陆腿安装在下降级的侧面，将下降级的底部保持在距离表面1.5米的高度。相对着陆腿脚垫末端的距离为9.4米。其中一条腿上有一个小的宇航员出舱平台和梯子。一个长1米的圆锥形下降发动机裙从下降级的底部突出。下降级包含着陆火箭、两个含有液氧燃料的罐、两个含有四氧化二氮氧化剂的罐、水、氧气和氦气罐，以及用于存储月球设备和实验的存储空间，在阿波罗15号、16号和17号任务中还包括月球车。下降级作为上升级的发射平台，被遗留在月球上。

上升级是一个不规则形状的单元，高约2.8米，宽4.0米×4.3米，安装在下降级的顶部。上升级内部有一个容积为6.65立方米的加压乘员舱，用于容纳宇航员。舱体一侧有一个进出口舱门，顶部有一个用于连接CSM的对接舱门。顶部还安装了一个抛物面会合雷达天线、一个可转向的抛物面S波段天线和两个机载VHF天线。进出口舱门上方和两侧各有一个三角形窗户，舱体侧面安装了四个推力室组件。组件底部是上升发动机。上升级还包含液氧燃料和氧化剂罐，以及氦气、液氧、气氧和反应控制燃料罐。月球模块中没有座椅。控制台安装在乘员舱前部进出口舱门上方，位于窗户和两侧两个更多控制面板之间。上升级在月球表面作业结束时从月球发射，并将宇航员送回CSM。

下降发动机是一种深节流烧蚀火箭，安装在下降级中心的万向环上，最大推力约为45,000 N。上升发动机是一种固定、恒定推力的火箭，推力约为15,000 N。机动通过反应控制系统实现，该系统由四个推力模块组成，每个模块由四个450 N推力的燃烧室和喷嘴组成，喷嘴指向不同的方向。遥测、电视、语音和与地球的测距通信都通过S波段天线进行。VHF用于宇航员与月球模块、月球模块和轨道中的CSM之间的通信。S波段和VHF都有冗余的收发机和设备。环境控制系统通过回收氧气并维持电子设备和乘员舱的温度来工作。电源由6个银锌电池提供。制导和导航控制由雷达测距系统、由陀螺仪和加速度计组成的惯性测量单元以及阿波罗制导计算机提供。

阿波罗月球表面实验包（ALSEP）

阿波罗月球表面实验包（ALSEP）由一组科学仪器组成，由宇航员在着陆点部署。仪器围绕一个中央站排列，该中央站为仪器提供电力，以便运行仪器和通信，以便将实验收集的数据传回地球。中央站是一个25公斤的箱子，存放体积为34,800立方厘米。热控制通过被动元件（隔热、反射器、热涂层）、功率耗散电阻器和加热器实现。通过一个58厘米长、3.8厘米直径的修改后的轴向螺旋天线与地球通信，该天线安装在中央站顶部，并由宇航员指向地球。发射机、接收机、数据处理器和多路复用器都安装在中央站内。从仪器收集的数据被转换为遥测格式并传送到地球。ALSEP系统和仪器由地球发出的命令控制。所有阿波罗任务ALSEP的上行频率为2119 MHz，阿波罗14号ALSEP的下行频率为2279.5 MHz。

放射性同位素热电发电机（RTG）

SNAP-27型号RTG为ALSEP操作提供了电力。该发电机由一个46厘米高的中央圆柱体和八个辐射矩形散热片组成，总尖端到尖端的直径为40厘米。中央圆柱体内部有一个较薄的同心内圆柱体，两个圆柱体通过沿其表面的442个弹簧加载铅锑热电偶连接，这些热电偶沿着圆柱体的长度径向安装。发电机组件的总质量为17公斤。燃料源是一个大约4公斤的长杆形燃料胶囊，其中包含钚-238，并由宇航员在部署时放置在RTG的内圆柱体中。钚-238的半衰期为89.6年，会产生热量。这种热量将通过热电偶从内圆柱体传导到外圆柱体，热电偶将热量直接转换为电能。外圆柱体上的多余热量将通过散热片辐射到太空中。RTG产生大约70 W DC的16 V电压。（一年后为63.5 W。）电力通过电缆输送到中央站中的电力调节单元和电力分配单元，为每个仪器提供正确的电压和功率。

ALSEP科学仪器

所有ALSEP仪器都是由宇航员在月球表面部署的，并通过电缆连接到中央站。阿波罗14号ALSEP仪器包括：（1）一个被动式地震仪，用于测量月球地壳和内部的结构性活动；（2）一个主动式地震仪，用于研究月球表面和地下材料的物理性质以及局部近地表层的结构；（3）一个超热离子探测器，用于测量低能正离子的通量组成、能量和速度；（4）一个带电粒子月球环境实验，用于测量到达月球表面的太阳质子和电子的粒子能量；（5）一个冷阴极离子规，用于测量大气以及任何随时间或太阳活动而变化的这种大气；（6）一个月球尘埃探测器，用于测量尘埃积累、太阳能电池的辐射损伤以及反射的红外能量和温度。位于3.6440 S纬度、17.4775 W经度的中央站在1971年2月5日17:23 UTC启动，与其他ALSEP站一起于1977年9月30日关闭。