3.0 LUNAR SURFACE EXPERIMENTS

The experiments discussed in this section consist of those associated with the Apollo lunar surface experiments package (a suprathermal ion detector, a cold cathode gage, a passive seismometer, an active seismometer, and a charged particle environment detector), as well as a laser ranging retroreflector experiment, a lunar portable magnetometer experiment, a solar wind composition experiment, lunar geology, and soil mechanics. Descriptions of the purposes and equipment of experiments carried for the first time on previous missions are given in the reports of those missions, and the applicable reports are referenced where appropriate. A brief description of the experiment equipment used for the first time on Apollo 14 is given in appendix A.

Lunar surface scientific activities were performed generally as planned within the allotted time periods. Approximately 5 1/2 hours after landing, the crew egressed the lunar module for the first traverse of the lunar surface. During the first extravehicular activity period, which lasted 4 hours 47 minutes 50 seconds, the crew:

a. Deployed the modular equipment stowage assembly.

b. Deployed and operated the color television camera as required to televise crew activities in the vicinity of the lunar module.

c. Transferred a contingency sample to the lunar module.

d. Erected the United States flag and the solar wind composition foil.

e. Deployed and loaded the modular equipment transporter used to aid the astronauts in transporting equipment and samples.

f. Collected surface samples including two 'small-football-size' specimens weighing approximately 4.4 and 5.5 pounds (2 and 2.5 kg).

g. Photographed activities, panoramas and equipment.

h. Deployed the Apollo lunar surface experiments package for the continuing collection of lunar scientific data via radio link.

Following a planned rest period, the second extravehicular activity period began with preparations for an extended geological traverse. The duration of the second extravehicular activity period was 4 hours 34 minutes 41 seconds, covering a traverse of approximately 1.6 miles, during which the crew:
a. Obtained lunar portable magnetometer measurements at two sites along the traverse.

b. Collected documented, core tube, and trench-site samples.

c. Collected a "large-football-size" specimen weighing approximately 19 pounds.

d. Photographed the area covered, including panoramas and sample sites.

e. Retrieved the solar wind composition foil.

f. Adjusted the antenna on the Apollo lunar surface experiments package central station.

The evaluations discussed in this section are based on the data obtained during the first lunar day - largely on crew comments and real-time information. Certain equipment difficulties mentioned in this section are discussed in greater detail in section 14.4. More comprehensive results will be summarized in a separate science report to be published when the detailed analyses are complete (appendix E). The sites at which the various lunar surface activities were conducted are shown in the figure 3-1. The specific activities at each location are identified in table 3-I.

Figure 3-1.-Traverse for the first and second extravehicular periods.



Table 3-I - LUNAR SURFACE ACTIVITIES

STATION ACTIVITY
FIRST EXTRAVEHICULAR ACTIVITY PERIOD
Lunar Module Sampling and photography
Apollo-lunar surface experiments
package deployment site
Apollo-lunar surface experiment
activities and photography
Laser ranging
retro-reflector site
Deployment of instrument
and photography
Comprehensive sample site Sampling and photography
Small-football-size rock site Sampling and photography
SECOND EXTRAVEHICULAR ACTIVITY PERIOD
A Sampling, photography and
first deployment of
lunar portable magnetometer
B Sampling and photography
B to B1 Sampling
B1 Photography
B2 Sampling and photography
B3 Photography
C' Sampling, photography and
second deployment of
lunar portable magnetometer
C1 Sampling and photography
C2 Sampling and photography
C2 to E Sampling
E Sampling
F Sampling and photography
G Sampling and photography
G1 Sampling and photography
H Sampling and photography



3.1 APOLLO LUNAR SURFACE EXPERIMENTS PACKAGE

The Apollo lunar surface experiments package was deployed with the central station positioned 600 feet west-northwest of the lunar module (fig. 3-2). No difficulties were experienced in off-loading the pallets or setting them up for the traverse other than an initial difficulty in latching the dome removal tool in the fuel cask dome. The crew installed the fuel capsule in the radioisotope thermoelectric generator and lockon data were obtained with initial antenna alignment at 116 hours 48 minutes.

Figure 3-2.-Arrangement of the Apollo lunar surface experiments.



3.1.1 Central Station

Initial conditions of the central station (ref. 1) were normal. Power output of the radioisotope thermoelectric generator was 69.1 watts, and the central station thermal plate temperature averaged 73.8 ° F. A reserve power reading of 43.5 watts indicated that the basic power consumption was normal for Apollo lunar scientific experiment package startup. As the generator warmed up, the power output increased to 72.0 watts and has remained nearly constant at that level.

The transmitter signal strength at initial acquisition was lower than expected, and about 4 dB lower than that of the Apollo 12 experiment package. This was partially the result of acquisition occurring at the time of the worst-case condition of the relative earth-moon positions. In addition, lunar surface photography shows that the antenna was not fully seated in the gimbal interface socket (resulting in a misalignment with gimbal settings) and the gimbal pointing toward the earth was off the nominal pointing angle. Subsequent monitoring indicates that the signal strength obtained from the Apollo 14 unit is now equal to that of the Apollo 12 unit and that signal strength variation can be predicted based on the relative earth-moon positions.

The Apollo lunar scientific experiment package central station was commanded to the hiih-bit-rate mode at 116 hours 56 minutes for the active seismic experiment/thumper mode of operation, which continued until 117 hours 34 minutes. Using the high-bit-rate mode, only the active seismic experiment data and limited engineering data can be received from the central station. The other experiments were turned on following the active seismic experiment/thumper mode of operation.

During the deployment of the central station, the sunshield erected normally. However, the crew had to lift one side on three occasions because it was sagging. Lunar surface photography indicates that the sunshield had been bumped downward in a counterclockwise direction. However, the sagging condition has had no adverse effect on the central station thermal control system, and the central station has been operating within thermal limits.

The Apollo lunar scientific experiment package 12-hour timer pulses did not occur after initial central station turn-on. Subsequent tests verified that the mechanical section of the timer was not operating. The timer functions started to occur on February 11 and the timer provided 12-hour pulses thirteen times in succession before failing. Loss of the timer has no adverse effect of the Apollo lunar experiment package since all functions are being accomplished by ground command. This problem is discussed further in section 14.4.4.

The lunar dust detector of the central station is showing normal outputs from all three photoelectric cells. No changes in the outputs of these cells were observed during or after lunar module ascent, indicating that dust from the ascent engine exhaust did not settle on the central station.



3.1.2 Passive Seismic Experiment

The passive seismic experiment (ref. 2) was deployed 10 feet north of the central station (fig. 3-2). No difficulty was experienced in deploying the experiment other than the inability to make the ribbon cable lie flat on the surface under the thermal shroud skirt. All elements have operated as planned with the following exceptions.

a. The long-period vertical component seismometer is unstable in the normal mode (flat-response mode). (See section 14.4.6 for a discussion of this anomaly.) The problem was eliminated by removing the feedback filter and operating in the peaked-response mode. In this mode, the siesmometer has a resonant period of 2.2 seconds instead of the normal period of 15 seconds. Without the extended flat response, the lowfrequency data is more difficult to extract. However, useful data are being obtained over the planned spectrum by data processing techniques.

b. The gimbal motor which levels the Y-axis long-period seismometer has not responded to commands on several occasions. In these cases, the reserve power status indicates that no power is being supplied to the motor. The power control circuit of the motor is considered to be the most likely cause of this problem. Response to commands has been achieved in all cases by repeating the motor drive command. (See section 14.4.5 for a more detailed discussion of this problem.)



3.1.3 Active Seismic Experiment

The active seismic experiment (appendix A, section A.4.1) was deployed during the first extravehicular period with the first geophone approximately 10 feet southwest of the central station and the geophone array extending in a southerly direction (figs. 3-2 and 3-3). The Apollo lunar scientific experiment package was commanded to the high-bit-rate mode for 28 minutes during the active seismic experiment/thumper mode of operation. Thumping operations began at geophone 3 (the furthest from the central station) and proceeded for 300 feet at 15-foot intervals toward geophone 1.

The attempts to fire the initiators resulted in 13 fired and 5 misfired. Three initiators were deliberately not fired. In some instances, two attempts were made to fire an initiator. (See section 14.4.1 for further discussion of this anomaly.)

A calibration pulse was sent prior to the last thumper firing verifying that all three geophones were operational. The mortar package, was deployed 10 feet north-northwest of the central station and aimed to fire four grenades on command from earth to distances of 500, 1000, 3000 and 5000 feet in a northerly direction. Firing of the four mortars has not been scheduled. Postmission tests and analyses are being performed to establish the appropriate time and provisions for conducting this part of the experiment.

Figure 3-3.-Apollo lunar surface experiment package components deployed on the lunar surface.



3.1.4 Suprathermal Ion Detector Experiment

The suprathermal ion detector experiment (ref. 2) was deployed southeast of the Apollo lunar surface experiments package central station (fig. 3-2). Noisy data were received at turn-on (section 14.4.2) but the data were satisfactory after seal break and dust cover removal. The experiment is returning good scientific data, with low background rates. Despite a large amount of lunar dust which adhered to one end of the package when it fell over several times during deployment (fig. 3-4), the temperatures throughout the lunar day and night remained within the range allowed for the instrument. Photographs show that the instrument is properly deployed and aligned.

Figure 3-4.-Suprathermal ion detector and cold cathode gage experiment deployed on the lunar surface.



3.1.5 Cold Cathode Gage Experiment

The cold cathode gage (ref. 2) was deployed 4 feet southeast of the suprathermal ion detector, aimed slightly southwest (figs. 3-2 and 3-4). The deployment was accomplished after several attempts in which the crewman experienced difficulty with the stiffness of the connecting cables while handling the suprathermal ion detector experiment, the cold cathode gage, and the ground screen at the same time.

The experiment was first turned on shortly before lunar module depressurization for the second extravehicular activity. Commands were sent to the instrument to turn on the high voltage and to open the cold cathode gage seal. The cold cathode gage data came off the initial fullscale indications much more rapidly than expected, indicating that the seal may have been open earlier than commanded.

Because a spontaneous change in the operational mode of the cold cathode gage and the suprathermal ion detector experiment occurred after about 1/2 hour of operation, the high voltages were switched off until after lunar sunset. When the high voltages were switched back on after lunar sunset, the response of the cold cathode gage went to the most sensitive range, indicative of the low ambient pressure. When the pressure rose at lunar sunrise as expected, the mode of operation was changed by a ground command to a less sensitive range, and the calibrate pulses appeared normal. The experiment is operating normally.



3.1.6 Charged Particle Lunar Environment Experiment

The charged particle lunar environment experiment (ref. 3) instrument (figs. 3-2 and 3-5) was first commanded on at 117 hours 58 minutes during the first extravehicular activity for a 5minute functional test and the instrument was normal. The complete instrument checkout showed that prelaunch and postdeployment counting rates agreed within 20 percent, with the exception of channel 6 in analyzer B. The counting rates on channel 6 were twice as high as the prelaunch values. The condition is attributed to the behavior ' of scattered electrons in the physical analyzers which behave quite differently in the effectively zero magnetic field of the moon compared with the 0.5-gauss magnetic field of the earth. The high counting rates on channel 6 do not detrimentally affect the science data. All command functions of the instrument were executed with the exception of the forced heater mode commands. Subsequent to the checkout, the experiment was commanded to standby.

After lunar module ascent, the charged particle lunar environment experiment was commanded on at 142 hours 7 minutes and the dust cover was removed about 15 hours and 20 minutes later. Operating temperatures are nominal. The maximum temperature during lunar day is 1360 F and the minimum temperature during lunar night is minus 110 F. The instrument's operational heater cycled on automatically when the electronics temperature reached 320 F at lunar sunset, and was commanded on in the forced-on mode at 140 F, as planned.

The instrument, on one occasion, changed from the manual mode (at the plus 3500-volt step) to the automatic mode. The instrument was subsequently commanded back into the manual mode. There is no evidence in the data which would indicate the cause of the mode change.

Figure 3-5.-Charged particle lunar environment experiment deployed on the lunar surface.



3.2 LASER RANGING RETRO-REFLECTOR

The laser ranging retro-reflector (ref. 4) was deployed during the first extravehicular activity at a distance of approximately 100 feet west of the Apollo lunar scientific experiment package central station (figs. 3-2 and 3-6). Leveling and alignment were accomplished with no difficulty. The instrument was ranged on by the McDonald Observatory team prior to lunar module lift-off and a high-quality return signal was received. Ranging after lift-off, while not yet conclusive, indicates no serious degradation of the retro-reflector resulting from the effects of the ascent stage engine firing.

Figure 3-6.-Laser ranging retro-reflecteur experiment deployed on the lunar surface.



3.3 LUNAR PORTABLE MAGNETOMETER EXPERIMENT

The lunar portable magnetometer (appendix A, section A.4.2) was deployed at site A and near the rim of Cone Crater (fig. 3-1) during the second extravehicular activity period. The instrument operated nominally in all respects. The temperature of the experiment electronics package reached equilibrium, between 1200 and 1500 F. Meter readings, relayed over the voice link, indicated total fields of 102 tlO gammas at site A and 41 tio gammas at Cone Crater. Vector component measurements of these readings were well within the dynamic range of the instrument. Leveling, orientation, and positioning were accomplished without difficulty; however, the experiment cable was difficult to rewind. This problem is discussed in greater detail in section 14.4.3.



3.4 SOLAR WIND COMPOSITION EXPERIMENT

The solar wind composition experiment (ref. 4), a specially prepared aluminum foil rolled on a staff, was deployed during the first extravehicular period for a foil exposure time of approximately 21 hours. Deployment was accomplished with no difficulty; however, during retrieval, approximately half the foil rolled up mechanically and the remainder had to be rolled manually.



3.5 LUNAR GEOLOGY

The landing site in the Fra Mauro highlands is characterized by northsouth trending linear ridges that are typically 160 to 360 feet in height and 6000 to 13 000 feet in width. The ridges and valleys are disfigured by craters ranging in size from very small up to several thousand feet in diameter.

The major objective of the geology survey was to collect, describe, and photograph materials of the Fra Mauro formation. The Fra Mauro formation is believed to be ejects, from the Imbrium Basin, which, in turn, is believed to have been created by a large impact. This material is probably best exposed in the vicinity of the landing site where it has been excavated from below the regolith by the impact that formed Cone Crater. The major part of the second extravehicular activity traverse, therefore, was designed to sample, describe, and photograph representative materials in the Cone Crater ejecta. Most of the returned rock samples consist of fragmental material. Photographs taken on the ejecta blanket of Cone Crater show various degrees of layering, sheeting, and foliation in the ejected boulders. A considerable variety in the nature of the returned fragmental rocks has been noted.

During the first extravehicular activity, the crew traversed a total distance of about 1700 feet. On their way back to the lunar module after deployment of the Apollo lunar scientific experiment package, the crew collected a comprehensive sample and two "footba.11-size" rocks. The comprehensive sample area was photographed with locator shots to the Apollo lunar scientific experiment package and to the lunar module prior to sampling, and stereo photographs were taken of the two "football-size" rocks before they were removed from the surface. The location of the Apollo, lunar scientific experiment package and the sampling and photographic sites for the first extravehicular activity are shown in figure 3-1.

The traverse during the second extravehicular activity covered a total distance of about 10 000 feet. The actual line of traverse is shown in figure 3-1. The crew reached a point within about 50 feet of the rim of Cone Crater. The crew was behind the timeline when they neared the rim of the crater; therefore, several of the preplanned sample and photographic stations along the route back to the lunar module were omitted. There was difficulty in navigating to several of the preplanned station points because of the undulations in the surface which prevented sighting of the smaller landmarks that were to be used.

The crew collected approximately 96 pounds of rock fragments and soil samples. Approximately 25 samples can be accurately located using photographs and the air-to-ground transcript, and the orientation of 12 to 15 on the lunar surface prior to their removal can be established.

Driving the core tubes with a rock hammer was somewhat difficult. The double and triple cores could not be driven their full length, and the material in the single core fell out upon removal of the core tube because of the granular nature of the material. Some sample material was recovered from the double and triple core tubes.

The only geologic equipment problems reported were that the contingency sample bag cracked when folded, and the vacuum seal protector on one of the special environmental sample containers came off when the container was opened.



3.6 LUNAR SOIL MECHANICS

Lunar surface erosion resulted from the descent engine exhaust as observed in previous lunar landings. Dust was first noted during descent at an altitude of 100 feet but did not hinder visibility during the final approach.

The lunar module footpad penetration on landing appears to have been greater than that observed on previous Apollo landings. Bootprint penetrations for the crew ranged from 1/2 to 3/4 inch on level ground in the vicinity of the lunar module to 4 inches on the rims of small craters. Lunar soil adhered extensively to the crewmen's clothing and equipment as in earlier Apollo missions. Tracks from the modular equipment transporter were 1/4 to 3/4 inch deep and were smooth.

The Apollo simple penetrometer (also used as the geophone cable anchor) was used for three penetration tests. In each case, the 26 1/2inch-long penetrometer could be pushed to a depth of 16 to 19 inches with one hand and to the extension handle with both hands. No penetration interference attributable to rocks was encountered.

A soil mechanics trench was dug in the rim of a small crater near North Triplet Crater. Excavation was easy, but was terminated at a depth of 18 inches because the trench walls were collapsing. Three distinct layers were observed and sampled: (1) The surface material was dark brown and fine-grained. (2) The middle layer was thin and composed predominantly of glassy patches. (3) The lower layer was very light colored granular material.



3.7 MODULAR EQUIPMENT TRANSPORTER

The modular equipment transporter (described in appendix A, section A.2.1 and shown in fig. 3-7) was deployed at the beginning of the first extravehicular activity. Deployment was impeded by the thermal blanket which restrained the modular equipment transporter from rotating down from the bottom of the modular equipment stowage assembly. The crew released the transporter by pulling the upper pip-pins and allowing the transporter and thermal blanket to fall freely to the lunar surface. The thermal blanket was easily discarded and erection of the transporter went as planned. The tires had inflated as expected. Equipment was loaded on the transporter without difficulty. Two of the three pieces of Velcro which held the lunar maps on the transporter handles came off at the beginning of the first extravehicular activity. These pieces had been glued on a surface having a different finish than the one to which the Velcro adhered.

The modular equipment transporter stability was adequate during both traverses. Rotation in roll was felt by the crewman through the handle but was easily restrained by using a tighter grip if the rotation sensed was excessive. The jointed legs in the front of the transporter operated as expected in that they flexed when hit and would spring back to the vertical position readily. The smooth rubber tires threw no noticeable dust. No dust was noted on the wheel fenders or on top of the metal frame of the transporter.

The modular equipment transporter was carried by both crewmen at one point in the second extravehicular activity to reduce the effort required for one crewman to pull the vehicle. This was done for a short period of time because it was believed to be more effective when traveling over certain types of terrain.

Figure 3-7.-Modular equipment transporter in use during the second extravehicular period.



3.8 APOLLO LANDING SITES

The Apollo 11 through 14 missions have placed a considerable amount of equipment on the lunar surface. Figure 3-8 shows the locations of all Apollo hardware that has been placed or impacted on the lunar surface.

Figure 3-8.-Apollo landing site and hardware locations on lunar surface.

Chapter 4 - Lunar Orbital Experiments Table of Contents Apollo 14 Journal Index