NAA awarded a development contract for the Apollo spacecraft fuel cell to Pratt & Whitney Aircraft Division of United Aircraft Corporation.

Charles W. Frick, Manager of the MSC Apollo Spacecraft Project Office, together with Maxime A. Faget, Charles W. Mathews, Christopher C. Kraft, Jr., John B. Lee, Owen E. Maynard, and Alan B. Kehlet of MSC and George M. Low of the NASA Office of Manned Space Flight, visited NAA at Downey, Calif. This was the first monthly meeting of the Apollo design and review team to survey NAA's progress in various areas, including the Apollo spacecraft heatshield, fuel cells, and service module.

NAA studies resulted in significant changes in the command module environmental control system (ECS).

1. Among modifications in the ECS schematic were included:
   1. Reduction in the cooling water capacity
   2. Combining into one command module tank the potable water and cooling water needed during boost
   3. Elimination of the water blanket for radiation protection.
2. More water would be generated by the fuel cells than necessary and could be dumped to decrease lunar landing and lunar takeoff weight.
3. Airlock valving requirements would permit two or more crewmen to perform extravehicular operation simultaneously. Area control of the space radiator to prevent coolant freezing was specified.
4. A new concept to integrate heat rejection from the spacecraft power system and the ECS into one space radiator subsystem was developed. This subsystem would provide full versatility for both lunar night and lunar day conditions and would decrease weight and complexity.
5. Because of the elimination of the lunar supplemental refrigeration system and deployable radiators, the water-glycol coolant system was modified:
   1. Removal from the service module of the coolant loop regenerative heat exchanger
   2. Replacement by a liquid valving arrangement of the gas-leak check provision at the radiator panels
   3. Changeover to a completely cascaded system involving the suit-circuit heat exchanger, cabin heat exchanger, and electronic component coldplate.

NAA evaluated the possibility of integrating the fuel cell and environmental control system heat rejection into one system. The integrated system proved to be unsatisfactory, being 300 pounds heavier and considerably more complex than the two separate systems. A preliminary design of separate fuel cell radiators, possibly located on the service module, was started by NAA.

Beech Aircraft Corporation was selected by NASA to build the spherical pressure vessels that would be used to store in the supercritical state the hydrogen-oxygen reactants for the spacecraft fuel cell power supply.

A final decision was made by NAA to redesign the command module fuel cell radiator and associated tubing to accommodate a 30-psi maximum pressure drop. Pratt & Whitney Aircraft Division agreed to redesign their pump for this level.

MSC reported that the three liquid-hydrogen-liquid-oxygen fuel cells would supply the main and emergency power through the Apollo mission except for the earth reentry phase. Two of the fuel cells would carry normal electrical loads and one would supply emergency power. Performance predictions had been met and exceeded in single-cell tests. Complete module tests would begin during the next quarter. The liquid-hydrogen liquid-oxygen reactants for the fuel cell power supply were stored in the supercritical state in spherical pressure vessels. A recent decision had been made to provide heat input to the storage vessels with electrical heaters rather than the water-glycol loop. Three zinc-silver oxide batteries would supply power for all the electrical loads during reentry and during the brief periods of peak loads. One of the batteries was reserved exclusively for the postlanding phase. Eagle Picher Company, Joplin, Mo., had been selected in August as subcontractor for the batteries.

Pratt and Whitney Aircraft delivered the first three prototype-A fuel cells to North American.

The first fuel cell module delivered by Pratt and Whitney Aircraft to North American was started and put on load. The module operated normally and all test objectives were accomplished. Total operating time was four hours six minutes, with one hour at each of four loads-20, 30, 40, and 50 amperes. The fuel cell was shut down without incident and approximately 1,500 cubic centimeters (1.6 quarts) of water were collected.

MSC announced that, during a 14-day lunar mission, fuel cells in the Apollo CSM would produce about 220 liters (60 gallons) of potable water while furnishing power to operate the electronic equipment.

North American conducted three tests (4, 20, and 88 hours) on the CSM fuel cell. The third ended prematurely because of a sudden drop in output. (Specification life on the modules was 100 hours.)

During this same week, Pratt and Whitney Aircraft tested a LEM-type fuel cell for 400 hours without shutdown and reported no leaks.

Three Pratt and Whitney fuel cells were operated in a simulated space vacuum at North American for 19, 20, and 21 hours. This was the first time three cells were operated as an electrical power generating subsystem.

Joseph G. Thibodaux, Jr., MSC Propulsion and Power Division, reported at an Apollo Engineering and Development technical management meeting that the first J-2 firing of the service propulsion system engine was conducted at White Sands Missile Range (WSMR). Two fuel cell endurance tests of greater than 400 hours were completed at Pratt and Whitney. MSC would receive a single cell for testing during the month.

Beech Aircraft Corporation stopped all end-item acceptance tests of hydrogen and oxygen tanks as a result of interim failure reports issued against three tanks undergoing tests. Failures ranged from exceeding specification tolerances and failure to meet heat leak requirements to weld failure on the H2 tank. Beech would resume testing when corrective action was established and approved by North American.

North American halted testing on the hydrogen tanks for the CSM, produced by Beech, because of weld failures. Testing on a redesigned tank assembly began on May 8.

The net effect of a decision by ASPO Manager Joseph F. Shea in May was that the total fuel cell effort at both Pratt and Whitney and North American should be no more than $9.7 million during FY 1966. The decision as to the distribution of the funds was left to the discretion of the fuel cell subsystem manager.

The first fuel cell system test at White Sands Test Facility was conducted successfully. Primary objectives were: 1 to verify the capability of the ground support equipment and operational checkout procedure to start up, operate, and shut down a single fuel cell power plant; and 2 to evaluate fuel cell operations during cold gimbaling of the service propulsion engine.

NASA Apollo Program Director Samuel C. Phillips indicated his concern to MSC over the extensive damage to a number of fuel cell modules from operational errors during integrated system testing. Phillips pointed out that in addition to the added cost there was a possible impact on the success of the flight program. He emphasized the importance of standardizing the procedures for fuel cell activation and shutdown at North American Aviation, MSC, and KSC to maximize learning opportunities.

George M. Low told Joseph N. Kotanchik, Chief of MSC's Structures and Mechanics Division, that actions were pending on Pratt & Whitney pressure vessel failures. The pressure vessels were used in the Apollo fuel cell system. Kotanchik had spelled out a list of problem areas in connection with both the vessels and management interface between MSC and principal contractor North American Aviation, and between North American and its subcontractor Pratt & Whitney.

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.

To support the Apollo 13 Review Board, an MSC Apollo 13 Investigation Team, headed by Scott H. Simpkinson, was established with the several 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.

MSC Director Robert R. Gilruth reported MSC actions on the Apollo 13 Review Board recommendations.

- 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.