The Apollo Spacecraft - A Chronology.

Part 3 (G)

Man Circles the Moon, the Eagle Lands, and Manned Lunar Exploration

1970

1970

January 4

NASA had canceled the Apollo 20 mission and stretched out the remaining seven missions to six-month intervals, Deputy Administrator George M. Low told the press in an interview after dedication of the Lunar Science Institute (next to MSC in Houston). Budget restrictions had brought the decision to suspend Saturn V launch vehicle production after vehicle 515 and to use the Apollo 20 Saturn V to launch the first U.S. space station in 1972. (See also Jan. 7.)

UPI, "Apollo Missions Extended to '74," New York Times, Jan. 5, 1970, p. 10; NASA Administrator Thomas O. Paine in NASA News Release, "NASA Future Plans," press conference transcript, Jan. 13, 1970.

January 5-8

Detailed reports on the Apollo 11 sample analyses were presented at the Lunar Science Conference at MSC. Principal investigators covered the fields of geology, mineralogy, petrology, radiogenic isotopes, inorganic and organic chemistry, solar wind and cosmic ray spallation products, magnetic and electrical properties, physical properties, impact metamorphism, and micropaleontology. The results added up to the greatest single advance in the understanding of a planetary-size body attained to date.

Abstract, N. W. Hinners, Bellcomm, Case 340, "Significant Results Reported at the Apollo 11 Lunar Science Conference," Jan. 30, 1970.

January 6

An MSC Experiments Review Group was established to consider new or late experiments for the Apollo flights. The group would recommend MSC policy on changes in experiments and would serve as a management clearing house.

Memo, James A. McDivitt, MSC, to distr., "Apollo Experiments Review Group," Jan. 6, 1970.

January 6

North American Rockwell announced a reorganization to strengthen its operating divisions, streamline channels of communication, and place more direct responsibility for performance with top division management.

Ltr., J. Leland Atwood, North American Rockwell Corp., to Robert R. Gilruth, MSC, Jan. 6, 1970.

January 6

North American Rockwell declined to become a member of the Coordinated Aerospace Supplier Evaluation (CASE) organization. North American Rockwell stated that its Certified Special Processors system provided greater effectiveness, that there was no real assurance that a supplier listed in the CASE Register was capable of performing to all the requirements of the indicated specifications, and that participants in CASE were prohibited from any exchange of information concerning supplier inadequacies. Several processors discontinued by North American Rockwell because of poor performance were still enjoying the full benefit of listing in the CASE Register, with the implication of system acceptability and certified-processor status that the listing provided.

Ltr., George W. Jeffs, North American Rockwell Corp., to Kenneth S. Kleinknecht, MSC, Jan. 6, 1970.

January 7

NASA issued instructions for deletion of the Apollo 20 mission from the program (see January 4). MSC was directed to take immediate action to:

Stop work on LM-14 and determine its disposition.
Delete requirements for the Apollo 20 spacesuits and portable and secondary life support systems.
Determine disposition of CSM 115A pending a final decision as to its possible use in a second workshop mission.
Reevaluate orbital science experiments and assignments and prepare proposed revisions.

TWX, Rocco A. Petrone, NASA Hq., to MSC, "Apollo 20 Deletion," Jan. 7, 1970.

January 12

Dale D. Myers' appointment as NASA Associate Administrator for Manned Space Flight was announced effective January 12, to succeed Dr. George E. Mueller, who had joined General Dynamics Corp. in New York City as a Vice President. Before this appointment, Myers was Vice President and General Manager of the Space Shuttle Program, North American Rockwell Corp.

NASA News Release 70-4, Jan. 8, 1970.

January 14

The scientific debriefing of the Apollo 12 astronauts indicated there were areas of strong interest for which there was no data and that the data could have been provided by an Apollo lunar surface closeup stereo camera. These included three distinct kinds of soil noticed by the astronauts, strangely patterned surface in certain areas, glazings in craters, and fillets around certain rocks. To assist the Apollo 13 astronauts in making scientific judgment of targets to be documented, the following photography list was established: unexpected features, glassy features, rock-soil junction, undisturbed surface, surface patterns, rock surface, and craters.

Memos, Anthony J. Calio, MSC, to James A. McDivitt, MSC, "Experiment S184 on Apollo 13, Apollo Lunar Surface Close-up Photography," Jan. 14, 1970; Richard S. Johnston, MSC, to Lee R. Scherer, NASA Hq., "Close-up stereo camera utilization on Apollo 13," Jan. 27, 1970.

January 16

An MSC meeting to realign the Apollo 16-19 lunar orbital science experiments recommended that the Sounding Radar Experiment, S-167, be deleted and the Lunar Electromagnetic Sounder, S-168, should be developed and flown. Scientific-value for the experiments was ranked in the following descending priorities for the various scientific disciplines: geochemistry, particles and fields, imagery and geodesy, surface and subsurface profiles, and atmospheres.

Minutes, Lunar Orbital Experiments Review, Jan. 16, 1970; memo, James A. McDivitt, MSC, to Rocco A. Petrone, NASA Hq., "Lunar orbital science experiments," Jan. 21, 1970.

January 29

Ground rules for service module design and integration, established during recent changes in the lunar orbital science program (see January 16), were reported. The Apollo LM experiment hardware would be installed and tested at KSC. A single scientific instrument module configuration was being proposed for Apollo 16-19 with modification kits developed, as required, to install Apollo 18 and Apollo 19 experiments. An expanded Apollo LM data system would be available for Apollo 16 (spacecraft 112).

Memo, James A. McDivitt, MSC, to Rocco A. Petrone, NASA Hq., "Apollo lunar orbital science program," Jan. 29, 1970.

February 5

North American Rockwell completed an investigation, requested by NASA, of the Apollo 12 flight anomalies associated with apparent vehicle electrostatic discharges at 36.5 and 52 seconds into the flight. The investigation indicated the most logical recommendation consistent with cost and schedule considerations to minimize or eliminate similar occurrences was for more restrictive launch rules. When atmospheric conditions exhibited electrostatic gradients in excess of several thousand volts with severe fluctuations or when heavy cloud conditions associated with frontal passages existed even in the absence of precipitation or reported spherics activities, delay of launch should be considered.

Ltr., George W. Jeffs, North American Rockwell Corp., to James A. McDivitt, MSC, Feb. 5, 1970.

February 6

A statement of agreements was reached between NASA Hq. and the Centers covering the requirements for a lunar roving vehicle (LRV). Appropriate portions of the agreements were being incorporated in a revised Apollo Program Specification and in Apollo Program Directive No. 4.

Memo, Rocco A. Petrone, NASA Hq., to MSFC, MSC, and KSC, "Lunar Roving Vehicle Requirements," Feb. 6, 1970.

February 17

MSC appointed a panel to investigate a February 13 accident at the Aerojet-General plant in Fullerton, Calif., that had damaged a lunar module descent tank beyond repair. Panel findings were reported to a review board later in the month, which recommended needed safety measures.

Ltr., O. G. Morris, MSC, to R. H. Tripp, Grumman, Feb. 17, 1970; memo for record, S. H. Simpkinson, MSC, "LM descent tank incident at Aerojet-General Corporation, California, on February 13, 1970," March 6, 1970.

March 7

In a White House release, President Nixon listed six specific objectives for the space program: continued exploration of the moon, exploration of the planets and the universe, substantial reductions in the cost of space operations, extension of man's capability to live and work in space, rapid expansion of the practical applications of space technology, and greater international cooperation in space.

Office of the Federal Register, National Archives and Records Service, Weekly Compilation of Presidential Documents, March 9, 1970, pp. 328-31.

March 13

Wernher von Braun was sworn in as NASA Deputy Associate Administrator for Planning. He left MSFC on March 1 and was succeeded as MSFC Director by Eberhard F. M. Rees.

Astronautics and Aeronautics, 1970 (NASA SP-4015, 1972), pp. 88-89.

April 6-10

Astronaut John L. Swigert, Jr., Apollo 13 backup command module pilot, began intensive training as a replacement for Thomas K. Mattingly II. The Apollo 13 prime crew had undergone a comprehensive medical examination after German measles had been contracted by Charles M. Duke, Jr., a member of the Apollo 13 backup crew. Mattingly had not shown immunity to the rubella virus and it was feared that he might become ill during the Apollo 13 flight.

MSC Apollo 13 Mission Report (MSC-02680), September 1970.

April 11-17

Apollo 13 (AS-508) was launched from Pad A, Launch Complex 39, KSC, at 2:13 p.m. EST April 11, with astronauts James A. Lovell, Jr., John L. Swigert, Jr., and Fred W. Haise, Jr., aboard. The spacecraft and S-IVB stage entered a parking orbit with a 185.5-kilometer apogee and a 181.5-kilometer perigee. At 3:48 p.m., onboard TV was begun for five and one-half minutes. At 4:54 p.m., an S-IVB burn placed the spacecraft on a translunar trajectory, after which the CSM separated from the S-IVB and LM Aquarius. (The crew had named lunar module 7 Aquarius and CSM 109 Odyssey.) The CSM then hard-docked with the LM. The S-IVB auxiliary propulsion system made an evasive maneuver after CSM/LM ejection from the S-IVB at 6:14 p.m. The docking and ejection maneuvers were televised during a 72-minute period in which interior and exterior views of the spacecraft were also shown.

At 8:13 p.m. EST a 217-second S-IVB auxiliary propulsion system burn aimed the S-IVB for a lunar target point so accurately that another burn was not required. The S-IVB/IU impacted the lunar surface at 8:10 p.m. EST on April 14 at a speed of 259 meters per second. Impact was 137.1 kilometers from the Apollo 12 seismometer. The seismic signal generated by the impact lasted 3 hours 20 minutes and was so strong that a ground command was necessary to reduce seismometer gain and keep the recording on the scale. The suprathermal ion detector experiment, also deployed by the Apollo 12 crew, recorded a jump in the number of ions from zero at the time of impact up to 2,500 shortly thereafter and then back to a zero count. Scientists theorized that ionization had been produced by 6,300 K to 10,300 K (6,000 degrees C to 10,000 degrees C) temperature generated by the impact or that particles had reached an altitude of 60 kilometers from the lunar surface and had been ionized by sunlight.

Meanwhile back in the CSM/LM, the crew had been performing the routine housekeeping duties associated with the period of the translunar coast. At 30:40 ground elapsed time a midcourse correction maneuver took the spacecraft off a free-return trajectory in order to control the arrival time at the moon. Ensuring proper lighting conditions at the landing site. The maneuver placed the spacecraft on the desired trajectory, on which the closest approach to the moon would be 114.9 kilometers.

At 10:08 p.m. EST April 13, the crew reported an undervoltage alarm on the CSM main bus B, rapid loss of pressure in SM oxygen tank No. 2, and dropping current in fuel cells 1 and 3 to a zero reading. The loss of oxygen and primary power in the service module required an immediate abort of the mission. The astronauts powered up the LM, powered down the CSM, and used the LM systems for power and life support. The first maneuver following the abort decision was made with the descent propulsion system to place the spacecraft back in a free-return trajectory around the moon. After the spacecraft swung around the moon, another maneuver reduced the coast time back to earth and moved the landing point from the Indian Ocean to the South Pacific.

About four hours before reentry on April 17, the service module was jettisoned and the crew took photographs and made visual observations of the damaged area. About one hour before splashdown the command module was powered up and the lunar module was jettisoned. Parachutes were deployed as planned, and the Odyssey landed in the mid-Pacific 6.4 kilometers from the recovery ship U.S.S. Iwo Jima at 1:07 p.m. EST April 17. The astronauts were picked up by helicopter and transported to the recovery ship less than an hour after splashdown.

MSC "Apollo 13 Mission Report" (MSC-02680), Sept. 1970; MSC "Apollo 13 (AS-508) Flight Summary," undated; memos, C. M. Lee, NASA Hq., to distr., "Mission Director's Summary Report, Apollo 13," April 17, 1970; E. R. Mathews, KSC, "Apollo 13 (AS-508) Post-Launch Report," April 24, 1970.

April 13

MSC informed NASA Hq. that the Apollo 12 ALSEP left on the moon in November 1969 was continuing to transmit satisfactory data. Status of experiments feeding data into the station was as follows:

The operation of the solar wind experiment was satisfactory. During the lunar days, useful data were being received from the lunar surface magnetometer. However, during the lunar-night cycle data were not received.

Useful data were being received from the three long-period sensors of the passive seismometer experiment. The short period sensor was inoperative.

The cold cathode ion gauge power had failed.

Satisfactory data were being received from the suprathermal ion detector.

Ltr., James A. McDivitt, MSC, to Rocco A. Petrone, NASA Hq., "Operational Status of Apollo 12 ALSEP," April 13, 1970.

April 13-June 15

"Hey, we've got a problem here." The message from the Apollo 13 spacecraft to Houston ground controllers at 10:08 p.m. EDT on April 13, initiated an investigation to determine the cause of an oxygen tank failure that aborted the Apollo 13 mission. The investigation terminated on June 15, when the Review Board accident report was released by NASA at a Headquarters press conference.

The Apollo 13 Review Board was established April 17 by George M. Low, NASA Deputy Administrator, and Thomas O. Paine, NASA Administrator, who appointed the Director of Langley Research Center, Edgar M. Cortright, as Review Board Chairman. On April 21 the members of the Board were named. In addition, by separate memos of April 20, the Aerospace Safety Advisory Panel was requested to review the procedures and findings of the Board and the Associate Administrator for Manned Space Flight was directed to provide records, data, and technical support as requested by the Board. The investigation indicated the accident was caused by a combination of mistakes and a somewhat deficient design. The following sequence of events led to the accident:

After assembly and acceptance testing, the oxygen tank no. 2 that flew on Apollo 13 was shipped from Beech Aircraft Corp. to North American Rockwell (NR) in apparently satisfactory condition.
However, the tank contained two inadequate protective thermostatic switches on the heater assembly, and they subsequently failed during ground test operations at Kennedy Space Center (KSC).
In addition, the tank probably contained a loosely fitting fill tube assembly. This assembly was probably displaced during subsequent handling, which included an incident at the prime contractor's plant in which the tank was jarred.
In itself, the displaced fill tube assembly was not particularly serious, but it led to improvised detanking procedures at KSC, which "almost certainly set the stage for the accident."
Although Beech had not met any problem in detanking during acceptance tests, it was not possible to detank oxygen tank no. 2 using normal procedures at KSC. Tests and analyses indicate that the problem was gas leakage through the displaced fill tube assembly.
The special detanking procedures at KSC subjected the tank to an extended period of heater operation and pressure cycling. "These procedures had not been used before, and the tank had not been qualified by test for the conditions experienced. However, the procedures did not violate the specifications which governed the operation of the heaters at KSC."
In reviewing these procedures before the flight, officials of NASA, NR, and Beech did not recognize the possibility of damage from overheating. Many were not aware of the extended heater operation. In any event, adequate thermostatic switches might have been expected to protect the tank.
A number of factors contributed to the presence of inadequate thermostatic switches in the heater assembly. The original 1962 specifications from NR to Beech Aircraft Corp. for the tank and heater assembly specified the use of 28-volt, direct-current power, which was used in the spacecraft. In 1965, NR issued a revised specification that stated the heaters should use a 65-volt dc power supply for tank pressurization; this was the power supply used at KSC to reduce pressurization time. Beech ordered switches for the Block II tanks but did not change the switch specifications to be compatible with 65-volt dc.
The thermostatic switch discrepancy was not detected by NASA, NR, or Beech in their review of documentation, nor did tests identify the incompatibility of the switches with the ground support equipment (GSE) at KSC, "since neither qualification nor acceptance testing required switch cycling under load as should have been done. It was a serious oversight in which all parties shared."
The thermostatic switches could accommodate the 65-volt dc during tank pressurization because they normally remained cool and closed. However, they could not open without damage with 65 volt dc power applied. They were not required to open until the special detanking. During this procedure, as the switches started to open when they reached their upper temperature limit, they were welded permanently closed by the resulting arc and were rendered inoperative as protective thermostats.
Failure of the thermostatic switches to open could have been detected at KSC if switch operation had been checked by observing heater current readings on the oxygen tank heater control panel. Although not recognized at the time, the tank temperature readings indicated that the heaters had reached their temperature limit "and switch opening should have been expected."
Subsequent tests showed that failure of the thermostatic switches probably permitted the temperature of the heater tube assembly to reach about 1,000 degrees F [810 K] in spots during the continuous eight-hour period of heater operation. Such heating had been shown by tests to damage severely the Teflon insulation on the fan motor wires near the heater assembly. "From that time on, including pad occupancy , the oxygen tank no. 2 was in a hazardous condition when filled with oxygen and electrically powered."
Nearly 56 hours into the mission, the fan motor wiring, possibly moved by the fan stirring, short-circuited and ignited its insulation. Combustion in the oxygen tank "probably overheated and failed the wiring conduit where it entered the tank, and possibly a portion of the tank itself."
The rapid expulsion of high-pressure oxygen which followed, "possibly augmented by combustion of insulation in the space surrounding the tank, blew off the outer panel to bay 4 of the SM, caused a leak in the high-pressure system of oxygen tank no. 1, damaged the high-gain antenna, caused other miscellaneous damage, and aborted the mission."

Based on the findings of the Board, a number of recommendations were made to preclude similar accidents in future space flights:

The cryogenic oxygen storage system in the service module should be modified to:
1. Remove from contact with the oxygen all wiring and unsealed motors that could potentially short-circuit and ignite adjacent materials; or otherwise ensure against an electrically induced fire in the tank.
2. Minimize the use of Teflon, aluminum, and other relatively combustible materials in the presence of the oxygen and potential ignition sources.
The modified cryogenic oxygen storage system should be subjected to a rigorous requalification program, including careful attention to potential operational problems.
The warning systems on the Apollo spacecraft and in the Mission Control Center should be carefully reviewed and modified where appropriate, with specific attention to:
1. Increasing the differential between master alarm trip levels and expected normal operating ranges to avoid unnecessary alarms.
2. Changing the caution and warning system logic to prevent an out-of-limits alarm from blocking another alarm if a second quantity in the same subsystem went out of limits.
3. Establishing a second level of limit sensing in Mission Control on critical quantities, with a visual or audible alarm that could not be easily overlooked.
4. Providing independent talk-back indicators for each of the six fuel cell reactant valves plus a master alarm when any valve closed.
Consumables and emergency equipment in the LM and the CM should be reviewed to determine whether steps should be taken to enhance their potential for use in a 'lifeboat' mode.
MSC should complete the special tests and analyses under way to understand more completely the details of the Apollo 13 accident. In addition, the lunar module power system anomalies should receive careful attention. Other NASA Centers should continue support to MSC in the areas of analysis and test.
Whenever significant anomalies occurred in critical subsystems during final preparation for launch, standard procedures should require a presentation of all prior anomalies on that particular piece of equipment, including those which have previously been corrected or explained. Critical decisions on flightworthiness should require the full participation of an expert "intimately familiar with the details of that subsystem."
NASA should thoroughly reexamine all its spacecraft, launch vehicle, and ground systems containing high-density oxygen or other strong oxidizers, to identify and evaluate potential combustion hazards in the light of information developed in this investigation.
NASA should conduct additional research on materials compatibility , ignition, and combustion in strong oxidizers at various gravity levels and on the characteristics of supercritical fluids. Where appropriate, new NASA design standards should be developed.
MSC should reassess all Apollo spacecraft subsystems, and the engineering organizations responsible for them at MSC and at its prime contractors, to ensure adequate understanding and control of the engineering and manufacturing details at the subcontractor and vendor level. "Where necessary, organizational elements should be strengthened and in-depth reviews conducted on selected subsystems with emphasis on soundness of design, quality of manufacturing, adequacy of test, and operational experience."

Memos, Low and Paine to Cortright, "Establishment of Apollo 13 Review Board," April 17, 1970; Low and Paine to Cortright, "Membership of Apollo 13 Review Board," April 21, 1970; Low and Paine to Chairman, Aerospace Safety Advisory Panel Charles D. Harrington, "Review of Procedures and Findings of Apollo 13 Review Board," April 20, 1970; Low and Paine to Dale D. Myers, NASA Hq., "Apollo 13 Review," April 20, 1970; ltr., Cortright to Paine, June 15, 1970; House Committee on Science and Astronautics, The Apollo 13 Accident: Hearings, 91st Cong., 2nd sess., June 16, 1970, pp. 234-36, 273-74.

April 19

To support the Apollo 13 Review Board, an MSC Apollo 13 Investigation Team, headed by Scott H. Simpkinson, was established with the following panels: spacecraft incident investigation, flight crew observations, flight operations and network ; photograph handling, processing, and cataloging ; corrective action study and implementation for the CSM, LM, and government-furnished equipment; related system evaluation; reaction processes in high-pressure fluid systems; high-pressure oxygen system survey; public affairs; and administration, communications, and procurement.

Memos, James A. McDivitt, MSC, to Apollo 13 Investigation Team, "Apollo 13 Investigation Team organization," April 19, 1970; Owen G. Morris, MSC, to Scott H. Simpkinson, "Apollo 13 Investigation Team organization," April 20, 1970.

June 26

NASA Hq. and Center actions were initiated on recommendations of the Apollo 13 Review Board. The Associate Administrator for Space Science and Applications would take specific action on recommendations 6, 7, and 9 of the report as they applied to spacecraft, launch vehicles, aircraft, ground systems and laboratories under OSSA jurisdiction. Lewis Research Center was directed to conduct a comprehensive review of oxygen-handling practices in NASA programs. The Aerospace Safety Research and Data Institute was already conducting studies on oxygen handling in aerospace programs. Other Centers were taking action on Board recommendations as applicable. (See July 16 entry.)

Memos, George M. Low, NASA Hq., to Associate Administrator for Space Science and Applications, "Recommendations of the Apollo 13 Review Board," June 26, 1970; Low to Director, Lewis Research Center, "Expansion of ASRDI Oxygen Systems Review," June 26, 1970; T. O. Paine, NASA Hq., to Director, Lewis Research Center, "Review of Oxygen Handling in Aerospace Programs to be Conducted by the Aerospace Safety Research and Data Institute (ASRDI)," May 19, 1970; Bruce T. Lundin, Lewis Research Center to Deputy Administrator, "Proposed oxygen handling program," July 14, 1970; Deputy Associate Administrator for Space Science and Applications (Engineering) to distr., "Recommendations of the Apollo 13 Review Board," Aug. 5, 1970.

July 14

Efforts of MSC personnel that had been redirected to support the Apollo 13 investigation would again be concentrated on the Apollo-experience-reporting project in an effort to attain a publication date of November 1, 1970.

Memo, Scott H. Simpkinson, MSC, to distr., "Apollo experience reporting," July 14, 1970.

July 16

MSC moved to reassess all Apollo spacecraft subsystems and the engineering organizations responsible for them at MSC and its prime contractors, in response to Apollo 13 Review Board recommendation 9 (see April 13-June 15).

Memo, James A. McDivitt, MSC, to distr., "Apollo 13 Review Board Report - Recommendation #9," July 16, 1970; extract from recommendation 9 of the Apollo 13 Review Board Report.

July 17

During the anniversary of Apollo 11, NASA Administrator Thomas O. Paine said: "The success of Apollo 11 marked the beginning of a new and important phase of mankind - not just the triumphant end of a mission. The mission was a voyage of discovery, and an important part of the discovery was the revelation of the infinite human potential for achievement as an endless new frontier was opened for future generations.

"Our remarkable progress in the first dozen years of the space age demonstrates that no dreams are impossible of realization, that the prospects for progress and human betterment here on earth as well as in space are limitless. And you may be sure that despite changing program directions, NASA will continue to play an exciting and vigorous role in the avant-garde of human progress."

Paine, Message to NASA coworkers, July 17, 1970.

August 7

North American Rockwell announced that William B. Bergen, who had been serving as president of North American's Space Division, would become a corporate vice president with the title Group Vice President - Aerospace and Systems. This was one of a number of key organizational steps taken since January to improve and strengthen the North American management structure in response to significant changes that had occurred in the aerospace environment.

Ltr., Robert Anderson, North American Rockwell Corp., to Robert R. Gilruth, MSC, Aug. 11, 1970.

September 2

NASA was canceling Apollo missions 15 and 19 because of congressional cuts in FY 1971 NASA appropriations, Administrator Thomas O. Paine announced in a Washington news conference. Remaining missions would be designated Apollo 14 through 17. The Apollo budget would be reduced by $42.1 million, to $914.4 million - within total NASA $3.27 billion.

"Statement by Dr. Thomas O. Paine," Sept. 2, 1970; Astronauts and Aeronautics, 1970 (NASA SP-4015, 1972), pp. 248, 257, 284-85.

September 11

Modifications were made in MSFC's lunar roving vehicle simulator and the static mockup to eliminate extreme arm and hand fatigue felt by a flight crew member and other test subjects after driving 10 to 15 minutes in LRV simulator evaluation tests. A T-shaped handle was added to the pistol grip; a parking-brake release and a reduced brake-travel distance were incorporated; and a mechanical reverse lockout was added.

Memo, James A. McDivitt, MSC, to Richard G. Smith, MSFC, "Lunar roving vehicle hand controller," Sept. 11, 1970.

November 24

Changes in SM oxygen tank (old tank)

Apollo 13's service module oxygen tank.

Changes in SM oxygen tank (new tank)

Redesigned oxygen tank.

MSC Director Robert R. Gilruth reported MSC actions on the Apollo 13 Review Board recommendations (see April 13-June 15), including:

Fan motors had been removed from oxygen storage tanks in the service modules; the electrical leads had been encased in stainless steel sheaths with hermetically sealed headers and had been shielded from contact with the remaining Teflon parts.
The modified cryogenic oxygen storage system had been subjected to a comprehensive recertification program developed in close coordination by North American Rockwell, Beech Aircraft Corp., and NASA. Requirements were founded on environmental as well as operational factors necessary to prove design capability.
No major changes had been made in the caution and warning system.
The LM and CSM consumables and emergency equipment had been reviewed to determine any design changes required to provide a safe return from lunar orbit in the event of a service module cryogenic-oxygen-supply loss. Three design changes were made in the CSM related to the oxygen tanks, an LM descent battery, and a water storage system in the CM.
MSC had made special tests and analyses to understand the Apollo 13 accident better. The testing had reaffirmed the conclusions reached by the Apollo 13 Review Board.
Significant anomalies in critical subsystems during final preparation for launch would be analyzed and resolved with authorized and documented corrective action in much the same manner as employed during the missions. An Apollo Program Directive for identification and resolution of significant failures and anomalies had been issued.
A thorough reexamination of all spacecraft, launch vehicle, and ground systems containing high-density oxygen and other strong oxidizers was being made to identify and evaluate potential combustion hazards.
Additional research was being conducted on materials compatibility, ignition, and combustion in strong oxidizers at various gravity levels and on the characteristics of supercritical fluids. Arc-ignition tests of the Apollo 14 oxygen-storage-system materials in both normal and overstressed modes indicated a positive margin of safety.
MSC had organized a system-by-system task team effort and made comprehensive reassessments of each subsystem. Design and qualification of each subsystem was reaffirmed as adequate for current ground test and mission requirements with the exception of a heatshield blowout plug for dumping reaction-control-subsystem propellant for launch aborts.

Ltr., Gilruth to Edgar M. Cortright, LaRC, Nov. 24, 1970.

November 25

George M. Low, Acting NASA Administrator, discussed the significance of unmanned lunar probes Luna XVI and XVII launched by the U.S.S.R. September 12 and November 10. Luna XVI had brought lunar samples back to earth and Luna XVII had landed an unmanned Lunokhod roving vehicle on the moon's surface. Low stated in a letter to Chairman Clinton P. Anderson of the Senate Committee on Aeronautical and Space Sciences that while the two launches were impressive their contributions to science and technology were relatively minor. Low suggested that the main lesson to be learned from the two launches specifically and the U.S. and U.S.S.R. space programs in general was that while the Soviet launch rate was increasing that of the United States was decreasing. These trends in the two countries' space programs should be a cause of concern if the United States was interested in maintaining a position of leadership in space.

Ltr., Dale D. Myers, NASA Hq., to Robert R. Gilruth, MSC, Dec. 16, 1970; Congressional Record-Senate, Nov. 30, 1970, pp. S19001-02.