APOLLO 17

The Eleventh Mission:

The Sixth Lunar Landing

7 December–19 December 1972

 

 

Background

 

Apollo 17 was the third Type J mission, an extensive scientific investigation of the Moon on the lunar surface and from lunar orbit. Although the spacecraft and launch vehicle were similar to those for Apollo 15 and 16, some experiments were unique to this mission. It was also the final piloted lunar landing mission of the Apollo program.

 

The primary objectives were:

 

 

 

 

The targeted landing site, Taurus-Littrow, was selected because of the certainty of acquiring highlands material, the potential for superior orbital coverage, and for better use of the LRV.

 

The crew members were Captain Eugene Andrew “Gene” Cernan, (USN), commander; Commander Ronald Ellwin Evans (USN), command module pilot; and Harrison Hagan “Jack” Schmitt, Ph.D., lunar module pilot.

 

Selected as an astronaut in 1963, Cernan was making his third spaceflight. He had been pilot of Gemini 9-A and lunar module pilot of Apollo 10, the first test of the LM in lunar orbit and the dress rehearsal for the first piloted landing on the Moon. Born 14 March 1934 in Chicago, Illinois, Cernan was 38 years old at the time of the Apollo 17 mission. He received a B.S. in electrical engineering from Purdue University in 1956 and an M.S. in aeronautical engineering from the U.S. Naval Postgraduate School in 1963. His backup for the mission was Captain John Watts Young (USN).

 

Evans and Schmitt were making their first spaceflights. Born 10 November 1933 in St. Francis, Kansas, Evans was 39 years old at the time of the mission. He received a B.S. in electrical engineering from the University of Kansas in 1956 and a M.S. in aeronautical engineering from the U.S. Naval Postgraduate School in 1964, and he was selected as an astronaut in 1966.[1] His backup was Lt. Colonel Stuart Allen Roosa (USAF).

 

A geologist, Schmitt was the first true scientist to explore the Moon. Born 3 July 1935 in Santa Rita, New Mexico, he was 37 years old at the time of the Apollo 17 mission. Schmitt received a B.S. in science from the California Institute of Technology in 1957 and a Ph.D. in geology from Harvard University in 1964. He was selected as an astronaut in 1965. His backup was Colonel Charles Moss Duke, Jr. (USAF).

 

The capsule communicators (CAPCOMs) for the mission were Major Charles Gordon Fullerton (USAF), Lt. Colonel Robert Franklyn Overmyer (USMC), Robert Alan Ridley Parker, Ph. D., Joseph Percival Allen IV, Ph. D., Captain Alan Bartlett Shepard, Jr. (USN), Commander Thomas Kenneth “Ken” Mattingly, II (USN), Duke, Roosa, and Young. The support crew were Overmyer, Parker, and Fullerton. The flight directors were Gerald D. Griffin (first shift), Eugene F. Kranz and Neil B. Hutchinson (second shift), and M.P. “Pete” Frank and Charles R. Lewis (third shift).

 

The Apollo 17 launch vehicle was a Saturn V, designated SA-512. The mission also carried the designation Eastern Test Range #1701. The CSM was designated CSM-114, and had the call-sign “America.” The lunar module was designated LM-12, and had the call-sign “Challenger.”

 

 

Launch Preparations

 

The terminal countdown was picked up at T-28 hours on at 12:53:00 GMT on 5 December 1972. Scheduled holds were initiated at T-9 hours for nine hours and at T-3 hours 30 minutes for one hour.

 

The launch countdown proceeded smoothly until 2 minutes 47 seconds before the scheduled launch, when the Terminal Countdown Sequencer failed to issue the S-IVB LOX tank pressurization command. As a result, an automatic hold command was issued at T-30 seconds which lasted 1 hour 5 minutes 11 seconds. The countdown was recycled to T-22 minutes, but was held again at T-8 minutes to resolve the sequencer corrective action. This hold lasted 1 hour 13 minutes 19 seconds The countdown was then picked up at T-8 minutes and proceeded smoothly to launch. The delays totaled 2 hours 40 minutes.

 

During the night launch of Apollo 17, the Cape Kennedy area was experiencing mild temperatures with gentle surface winds. These conditions resulted from a warm moist air mass covering most of Florida. This warm air was separated from an extremely cold air mass over the rest of the south by a cold front oriented northeast-southwest and passing through the Florida panhandle. Surface winds in the Cape Kennedy area were light and northwesterly. The maximum wind belt was located north of Florida, giving less intense wind flow aloft over the Cape Kennedy area. At launch time, stratocumulus clouds covered 20 percent of the sky (base 2,600 feet) and cirrus clouds covered 50 percent (base 26,000 feet); the temperature was 70.0° F; the relative humidity was 93 percent; and the barometric pressure was 14.795 lb/in2. The winds, as measured by the anemometer on the light pole 60.0 feet above ground at the launch site measured 8.0 knots at 5° from true north. The winds at 530 feet above the launch site measured 10.5 knots at 335° from true north.

 

 

Ascent Phase

 

Apollo 17 was launched from Kennedy Space Center Launch Complex 39, Pad A, at a Range Zero time of 05:33:00 GMT (12:33:00 a.m. EST) on 7 December 1972. The planned launch window was 02:53:00 GMT to 06:31:00 GMT on 7 December to take advantage of a sun elevation angle on the lunar surface of 13.3°.

 

Between 000:00:12.9 and 000:00:14.3, the vehicle rolled from a launch pad azimuth of 90° to a flight azimuth of 91.503°. The S-IC engine shut down at 000:02:41.20, followed by S-IC/S-II separation, and S-II engine ignition. The S-II engine shut down at 000:09:19.66 followed by separation from the S-IVB, which ignited at 000:09:23.80. The first S-IVB engine cutoff occurred at 000:11:42.65, with deviations from the planned trajectory of only +1.0 ft/sec in velocity and only -0.1 n mi in altitude.

 

The maximum wind conditions encountered during ascent were 87.6 knots at 311° from true north at 38,945 feet, with a maximum wind shear of 0.0177 sec-1 at 26,164 feet.

 

Parking orbit conditions at insertion, 000:11:52.65 (S-IVB cutoff plus 10 seconds to account for engine tailoff and other transient effects), showed an apogee and perigee of 90.3 by 90.0 n mi, an inclination of 28.526°, a period of 87.83 minutes, and a velocity of 25,603.9 ft/sec. The apogee and perigee were based upon a spherical Earth with a radius of 3,443.934 n mi.

 

The international designation for the CSM upon achieving orbit was 1972-096A and the S-IVB was designated 1972-096B. After undocking at the Moon, the LM ascent stage would be designated 1972-096C and the descent stage 1972-096D.

 

 

Translunar Phase

 

After inflight systems checks, the 351.04-second translunar injection maneuver (second S-IVB firing) was performed at 003:12:36.60. The
S-IVB engine shut down at 003:18:27.64 and translunar injection occurred ten seconds later at a velocity of 35,555.3 ft/sec after two Earth orbits lasting 3 hours 6 minutes 44.99 seconds.

 

At 003:42:27.6, the CSM was separated from the S-IVB stage, transposed, and docked at 003:57:10.7. During docking, there were indications of a ring latch malfunction. The LM was pressurized, the hatch removed, and troubleshooting revealed that the handles for latches 7, 9, and 10 were not locked. All were manually set and the docked spacecraft were ejected from the S-IVB at 004:45:02.3. A 79.9-second separation maneuver was performed at 005:03:01.1.

 

The S-IVB tanks were vented at 006:09:59.8, and the auxiliary propulsion system was fired for 98.2 seconds to target the S-IVB for a lunar impact. A second, 102.2-second maneuver was performed at 011:14:59.8.

 

The S-IVB impacted the lunar surface at 086:59:42.3. The impact point was latitude 4.21° south and longitude 12.37° west, 84 n mi from the target point, 183 n mi from the Apollo 12 seismometer, 85 n mi from the Apollo 14 seismometer, 557 n mi from the Apollo 15 seismometer, and 459 n mi from the Apollo 16 seismometer. The impact was recorded by all four instruments. At impact, the S-IVB weighed 30,712 pounds and was traveling 8,366 ft/sec.

 

The 2-hour 40-minute launch delay caused ground controllers to modify Apollo 17’s trajectory so that it would arrive at the Moon at the originally scheduled time. They shortened the translunar coast time by having the crew make a 1.73-second 10.5 ft/sec midcourse correction at 035:29:59.91.

 

The commander and lunar module pilot transferred to the LM at 040:10. At ingress, it was discovered that #4 docking latch was not properly latched. The command module pilot moved the latch handle between 30° and 45°, disengaging the hook from the docking ring. After discussion with ground control, it was decided to curtail further action on the latch until the second LM activation. The remainder of the LM housekeeping was nominal and the LM was closed out at 042:11.

 

The heat flow and convection demonstrations were conducted as planned. The first demonstration began at 042:55 and was performed with the spacecraft in attitude hold while the second run was accomplished with the spacecraft in the passive thermal control mode. The demonstrations produced satisfactory results, and were concluded at 046:00.

 

The second LM housekeeping session commenced at 059:59 and was completed at 062:16. All LM systems checks were nominal. During the LM housekeeping period, the command module pilot performed troubleshooting on the docking latch #4 problem experienced during the first session. Following instructions from the ground controllers, he stroked the latch handle and succeeded in cocking the latch. The latch was left in the cocked position for the CSM/LM rendezvous.

 

At 065:39, a one-hour visual light flash phenomenon observation was conducted by the crew. They reported seeing light flashes ranging from bright to dull.

 

The SM scientific instrument module bay door was jettisoned at 081:32:40.

 

At 086:14:22.60, at an altitude of 76.8 n mi above the Moon, the service propulsion engine was fired for 393.16 seconds to insert the spacecraft into a lunar orbit of 170.0 by 52.6 n mi. The translunar coast had lasted 83 hours 2 minutes 18.11 seconds.

 

 

Lunar Orbit/Lunar Surface Phase

 

At 090:31:37.43, a 22.27-second service propulsion system maneuver was performed and lowered the spacecraft to the descent orbit of 59.0 by 14.5 n mi in preparation for undocking of the LM.

 

The CSM/LM combination was retained in this orbit 17 hours before the spacecraft were undocked and separated by a 3.4-second maneuver at 107:47:56 at an altitude of 47.2 n mi, while in an orbit of 61.5 by 11.5 n mi. After undocking, a 3.80-second maneuver at 109:17:28.92 circularized the CSM orbit to 70 by 54 n mi.

 

The second LM descent orbit insertion maneuver, performed for 21.5 seconds at 109:22:42, lowered the orbit to 59.6 by 6.2 n mi. The 725-second powered descent maneuver was initiated from this orbit at 110:09:53 at an altitude of 8.7 n mi.

 

Landing occurred at 19:54:58 GMT (02:54:58 p.m. EST) on 11 December at 110:21:58. The spacecraft landed in the Taurus-Littrow region at latitude 20.19080° north and longitude 30.77168° east, within 656 feet of the planned landing point. Approximately 117 seconds of engine firing time remained at landing.

 

The first extravehicular activity began at 114:21:49 with the depressurization of the LM cabin. After exiting to the surface, the crew offloaded the lunar roving vehicle (LRV-3) at 114:51:10.

 

After deploying the LRV, and prior to traversing to the ALSEP site, the commander inadvertently knocked the right rear fender extension off the LRV. The extension was subsequently secured to the fender with tape. Later during EVA-1, the extension came off and showered the crew and the LRV with a great deal of lunar dust.

 

Following an LRV test drive the crew gathered samples and performed panoramic photography.

 

The crew deployed the U.S. flag at 115:40:58 and offloaded the ALSEP package at 115:58:30. Following several traverse gravimeter readings, the ALSEP was deployed 607 feet (185 m) west-northwest of the LM.

 

At the ALSEP site, at 118:35:27, the CDR drilled two holes for heat flow experiment probes and a deep core hole.

 

At 119:56:47, the crew departed for the surface electrical properties experiment, with a stop to deploy a seismic profiling explosive charge.

 

The crew entered the LM and the cabin was repressurized at 121:33:42. The first EVA lasted 7 hours 11 minutes 53 seconds. The distance traveled in the lunar rover vehicle was 1.8 n mi (3.3 km), vehicle drive time was 33 minutes, and 31.53 pounds (14.3 kg) of samples were collected.

 

The second extravehicular activity began 80 minutes late, with cabin depressurization at 137:55:06.

 

Prior to starting the EVA traverse, ground controllers sent instructions for improvising a replacement for the lost fender extension. A rig of four maps, taped together and held in position by two clamps from portable utility lights, made an excellent substitute for the extension.

 

The crew loaded the LRV and departed for the surface electrical properties experiment site at 138:44:02. During the traverse, the extravehicular plan was modified to allow more time at points of geological interest.

 

The crew deployed three explosive packages in support of the lunar seismic profiling experiment, made seven traverse gravimeter measurements, gathered numerous samples, and completed their 500 mm and panoramic photographic tasks.

 

An orange-colored material, believed to be of volcanic origin, was found at station 4 (Shorty Crater).

 

The crew entered the LM and the cabin was repressurized at 145:32:02. The second extravehicular activity lasted 7 hours 36 minutes 56 seconds. The distance traveled in the lunar rover vehicle was 11.0 n mi (20.3 km), vehicle drive time was 2 hours 25 minutes, and 75.18 pounds (34.1 kg) of samples were collected.

 

After a 15 hour 30-minute period in the LM, the cabin was depressurized at 160:52:48 for the third EVA, about 50 minutes later than planned.

 

Specific sampling objectives were accomplished and nine traverse gravimeter measurements were made, as well as additional 500 mm and panoramic photography.

 

The surface electrical properties experiment was terminated because the receiver temperature was increasing to a level that could have affected the data tape. Consequently, the tape recorder was removed on the way back to the LM.

 

The cosmic ray experiment and the lunar neutron probe experiment were retrieved at 161:20:17, and several seismic profiling charges were deployed.

 

The crew entered the LM, and, following equipment jettison, the cabin was repressurized at 168:07:56, thus ending the sixth human exploration of the Moon.

 

The third EVA lasted 7 hours 15 minutes 8 seconds. The distance traveled in the lunar rover vehicle was 6.5 n mi (12.1 km), vehicle drive time was 1 hour 31 minutes, and 136.69 pounds (62.0 kg) of samples were collected.

 

For the mission, the total time spent outside the LM was 22 hours 3 minutes 57 seconds, the total distance traveled in the lunar rover vehicle was 19.3 n mi (35.7 km), vehicle drive time was 4 hours 29 minutes, and the collected samples totaled 243.65 pounds (110.52 kg; official total in kilograms as determined by the Lunar Receiving Laboratory in Houston). The farthest point traveled from the LM was 25,029 feet. Good quality television transmissions were received during all three EVAs.

 

Numerous science activities were conducted in lunar orbit while the surface was being explored. In addition to the panoramic camera, the mapping camera, and the laser altimeter (which were used on previous missions), three new experiments were included in the service module. An ultraviolet spectrometer measured lunar atmospheric density and composition, an infrared radiometer mapped the thermal characteristics of the Moon, and a lunar sounder acquired data on the subsurface structure.

 

The CSM orbit did not decay as predicted while the LM was on the Moon. Consequently, a 37.50-second orbital trim maneuver was performed at 178:54:05.45 to lower the orbit to 67.3 by 62.5 n mi. In addition, a planned 20.05-second plane change maneuver was made at 179:53:53.83 in preparation for rendezvous and resulted in an orbit of 62.8 by 62.5 n mi.

 

Ignition of the ascent stage engine for lunar liftoff occurred at 05:54:37 GMT (22:54:37 p.m. EST) [sic: Lunar liftoff actually occurred at 22:54:37 GMT, 17:54:37 EST. The original text mixes up the two times.] on 14 December at 185:21:37. The LM had been on the lunar surface for 74 hours 59 minutes 40 seconds.

 

The 441-second maneuver was made to achieve the initial lunar orbit of 48.5 by 9.1 n mi. Several rendezvous sequence maneuvers were required before docking could occur two hours later. A 10-second vernier adjustment maneuver at 185:32:12 adjusted the orbit to 48.5 by 9.4 n mi. Finally, the 3.2-second terminal phase initiation at 186:15:58 brought the ascent stage to an orbit of 64.7 by 48.5 n mi.

 

The ascent stage and the CSM docked at 187:37:15 at an altitude of 60.6 n mi. The two spacecraft had been undocked for 79 hours 49 minutes 19 seconds.

 

After transfer of the crew and samples to the CSM, the ascent stage was jettisoned at 191:18:31, and the CSM was prepared for transearth injection. The ascent stage was then maneuvered by remote control to strike the lunar surface.

 

A 12-second maneuver was made at 191:23:31 to separate the CSM from the ascent stage, and resulted in an orbit of 63.9 by 61.2 n mi. A 116-second deorbit firing at 60.5 n mi altitude depleted the ascent stage propellants by 193:00:10. Impact occurred at latitude 19.96° north and longitude 30.50° east at 193:17:20.8. The impact point was 0.7 n mi (1.75 km) from the planned point and 4.7 n mi (9.9 km) southwest of the Apollo 17 landing site. The impact was recorded by the Apollo 12, 14, 15, and 16 seismic stations.

 

The first two of eight explosive packages placed by the crew on the lunar surface were detonated at 210:15:14.56 and 212:44:57.11. Both events were picked up by the lunar seismic profiling geophones, and the resulting flash and dust from the second explosion were seen on television.

 

The television assembly and lunar communications relay unit failed to operate when attempts were made to command the camera on at 218:20, 235:04, and 235:13. It was later determined that the relay unit experienced an over-temperature failure.

 

The third lunar surface explosive package was detonated at 229:35:34.67.

 

Following a 143.69-second maneuver at 234:02:09.18 at an altitude of 62.1 n mi, transearth injection was achieved at 234:04:32.87, at a velocity of 8,374.3 ft/sec, after 75 lunar orbits lasting 147 hours 43 minutes 37.11 seconds. The crew had spent an additional day in lunar orbit performing scientific experiments.

 

 

Transearth Phase

 

The fourth and fifth explosive packages were detonated, at 235:09:36.79 and 238:12:46.08, and the geophones received strong signals.

 

At 254:54:40, the command module pilot began a 1-hour 5-minute 44-second transearth coast extravehicular activity, televised to Earth, during which he retrieved the lunar sounder film, panoramic camera, and mapping camera cassettes in three trips to the scientific instrument module bay. This brought the total extravehicular activity for the mission to 23 hours 9 minutes 41 seconds.

 

Three final explosive packages were detonated at 257:43:41.06, 259:11:56.82, and 261:44:28.28, and were detected by the lunar surface geophones.

 

During the remainder of transearth flight, the crew performed another light-flash experiment, and operated the infrared radiometer and ultraviolet spectrometer. One midcourse correction was required, a 9-second 2.1-ft/sec maneuver at 298:38:01.

 

 

Recovery

 

The service module was jettisoned at 301:23:49, and the CM entry followed a normal profile. The command module reentered Earth’s atmosphere (400,000 feet altitude) at 301:38:38 at a velocity of 36.090.3 ft/sec, following a transearth coast of 67 hours 34 minutes 05 seconds.

 

The parachute system effected splashdown of the CM in the Pacific Ocean at 19:24:59 GMT (02:24:59 p.m. EST) on 19 December. Mission duration was 301:51:59. The impact point was about 1.0 n mi from the target point and 3.5 n mi from the recovery ship U.S.S. Ticonderoga.

 

The splashdown site was estimated to be latitude 17.88° south and longitude 166.11° west. After splashdown, the CM assumed an apex-up flotation attitude. The crew was retrieved by helicopter and was aboard the recovery ship 52 minutes after splashdown. The CM was recovered 71 minutes later. The estimated CM weight at splashdown was 12,120 pounds, and the estimated distance traveled for the mission was 1,291,299 n mi.

 

The crew departed the Ticonderoga at 00:38 GMT on 21 December and arrived in Houston at 15:50 GMT. The CM was sent for deactivation to North Island Naval Air Station, San Diego, where it arrived at 19:30 GMT on 27 December. Deactivation was completed at 22:00 GMT on 30 December. The CM left North Island at 19:00 GMT on 2 January, and was delivered to the North American Rockwell Space Division facility in Downey, California, for postflight analysis. It arrived at 22:00 GMT.

 

 

Conclusions

 

All facets of the Apollo 17 mission were conducted with skill, precision, and relative ease because of experienced personnel and excellent performance of equipment. The following conclusions were made from an analysis of post-mission data:

 

  1. The Apollo 17 mission was the most productive and trouble-free piloted mission, and represented the culmination of continual advancements in hardware, procedures, training, planning, operations, and scientific experiments.

 

  1. The Apollo 17 mission demonstrated the practicality of training scientists to become qualified astronauts while retaining their expertise and scientific knowledge.

 

  1. Stars and the horizon were not visible during night launches, therefore out-of-the-window alignment techniques could not be used for attitude reference.

 

  1. The dynamic environment within the cabin during the early phases of the launch made system troubleshooting or corrective actions by the crew impractical. Therefore, either the ground control or automation should be relied upon for system troubleshooting and, in some cases, corrective actions.

 

  1. As a result of problems on this and other missions, further research was needed to increase the dependability of mechanisms used to extend and retract equipment repeatedly in the space environment.

 

[1] Evans died of a heart attack on 7 April 1990 in Scottsdale, Arizona.

 

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