The Apollo Spacecraft - A Chronology.|
Part 2 (K)
Recovery, Spacecraft Redefinition, and First Manned Apollo Flight
April 2NASA Hq. confirmed oral instructions to MSC and KSC to use 60 percent oxygen and 40 percent nitrogen to pressurize the Apollo CM cabin in prelaunch checkout operations and during manned chamber testing, as recommended by the Design Certification Review Board on March 7 and confirmed by the NASA Administrator on March 12. This instruction was applicable to flight and test articles at all locations.
TWX, Samuel C. Phillips to MSC, Attn: G. M. Low and KSC, Attn: R. O. Middleton, April 2, 1968.
April 2Eberhard F. M. Rees, Director of the Special Task Team at North American Rockwell, spearheaded a design review of the CM water sterilization system at Downey, Calif. (The review had resulted as an action item from the March 21 Configuration Control Board meeting in Downey.) Rees and a team of North American engineers reviewed the design of the system and test results and problems to date. Chief among performance concerns seemed to be compatibility of the chlorine solution with several materials in the system, maximum allowable concentration of chlorine in the water supply from the medical aspect, and contamination of the system during storage, handling, and filling. Assuming North American's successful completion of qualification testing and attention to the foregoing action items, said Rees, the system design was judged satisfactory.
Ltr., Dale D. Myers to George M. Low, April 8, 1968, with encl., "CSM Water Sterilization System CDR, April 2, 1968."
April 4Apollo 6 (AS-502) was launched from Complex 39A at Kennedy Space Center. The space vehicle consisted of a Saturn V launch vehicle with an unmanned, modified Block I command and service module (CSM 020) and a lunar module test article (LTA-2R).
Liftoff at 7:00 a.m. EST was normal but, during the first-stage (S-IC) boost phase, oscillations and abrupt measurement changes were observed. During the second-stage (S-II) boost phase, two of the J-2 engines shut down early and the remaining three were extended approximately one minute to compensate. The third stage (S-IVB) firing was also longer than planned and at termination of thrust the orbit was 177.7 x 362.9 kilometers rather than the 160.9-kilometer near-circular orbit planned. The attempt to reignite the S-IVB engine for the translunar injection was unsuccessful. Reentry speed was 10 kilometers per second rather than the planned 11.1, and the spacecraft landed 90.7 kilometers uprange of the targeted landing point.
The most significant spacecraft anomaly occurred at about 2 minutes 13 seconds after liftoff, when abrupt changes were indicated by strain, vibration, and acceleration measurements in the S-IVB, instrument unit, adapter, lunar module test article, and CSM. Apparently oscillations induced by the launch vehicle exceeded the spacecraft design criteria.
The second-stage (S-II) burn was normal until about 4 minutes 38 seconds after liftoff; then difficulties were recorded. Engine 2 cutoff was recorded about 6 minutes 53 seconds into the flight and engine 3 cutoff less than 3 seconds later. The remaining second-stage engines shut down at 9 minutes 36 seconds - 58 seconds later than planned.
The S-IVB engine during its first burn, which was normal, operated 29 seconds longer than programmed. After two revolutions in a parking orbit, during which the systems were checked, operational tests performed, and several attitude maneuvers made, preparations were completed for the S-IVB engine restart. The firing was scheduled to occur on the Cape Kennedy pass at the end of the second revolution, but could not be accomplished. A ground command was sent to the CSM to carry out a planned alternate mission, and the CSM separated from the S-IVB stage.
A service propulsion system (SPS) engine firing sequence resulted in a 442-second burn and an accompanying free-return orbit of 22,259.1 x 33.3 kilometers. Since the SPS was used to attain the desired high apogee, there was insufficient propellant left to gain the high-velocity increase desired for the entry. For this reason, a complete firing sequence was performed except that the thrust was inhibited.
Parachute deployment was normal and the spacecraft landed about 9 hours 50 minutes after liftoff, in the mid-Pacific, 90.7 kilometers uprange from the predicted landing area. A normal retrieval was made by the U.S.S. Okinawa, with waves of 2.1 to 2.4 meters.
The spacecraft was in good condition, including the unified crew hatch, flown for the first time. Charring of the thermal protection was about the same as that experienced on the Apollo 4 spacecraft (CM 017).
Of the five primary objectives, three - demonstrating separation of launch vehicle stages, performance of the emergency detection system (EDS) in a close-loop mode, and mission support facilities and operations - were achieved. Only partially achieved were the objectives of confirming structure and thermal integrity, compatibility of launch vehicle and spacecraft, and launch loads and dynamic characteristics; and of verifying operation of launch vehicle propulsion, guidance and control, and electrical systems. Apollo 6, therefore, was officially judged in December as "not a success in accordance with . . . NASA mission objectives."
Memos, Chief, Landing and Recovery Div. to Director of Flight Operations, MSC, "Apollo 6 preliminary recovery information," April 5, 1968; Apollo Program Director Samuel C. Phillips to Administrator, NASA, "Apollo 6 Mission (AS-502) Post Launch Report #1," April 18, 1968, with attachment, "Post Launch Mission Operation Report No. M-932-68-06"; Phillips to Acting Administrator, "Apollo 6 Mission (AS-502) Post Launch Report #2," Dec 27, 1968; "Apollo 6 Mission Report," prepared by Apollo 6 Mission Evaluation Team, approved by George M. Low, June 1968.
April 4Howard W. Tindall, Jr., Chief of Apollo Data Priority Coordination, reported that several meetings devoted to the question of the LM's status immediately after touching down on the lunar surface, had reached agreement on several operational techniques for a "go/no go" decision. Basically, the period immediately after landing constituted a system evaluation phase (in which both crew and ground controllers assessed the spacecraft's status) - a period of about two minutes, during which immediate abort and ascent was possible. Given a decision at that point not to abort, the crew would then remove the guidance system from the descent mode and proceed with the normal ascent-powered flight program (and an immediate abort was no longer possible). Assuming permission to stay beyond this initial "make ready" phase, the crew would then carry out most of the normal procedures required to launch when the CM next passed over the landing site (some two hours later).
Memo, Tindall to distr., "Mission techniques for the LM lunar stay go/no go," April 4, 1968.
April 5-7Astronauts James A. Lovell, Jr., Stuart A. Roosa, and Charles M. Duke, Jr., participated in a recovery test of spacecraft 007, conducted by the MSC Landing and Recovery Division in the Gulf of Mexico. The test crew reported that while they did not "recommend the Apollo spacecraft for any extended sea voyages they encountered no serious habitability problems during the 48-hour test. If a comparison can be made, the interior configurations and seaworthiness make the Apollo spacecraft a much better vessel than the Gemini spacecraft." The following conclusions were reached:
April 10The Apollo spacecraft Configuration Control Board (CCB) had endorsed changes in lunar orbit insertion and LM extraction on the lunar mission flight profile, the MSC Director notified the Apollo Program Director. ASPO had reviewed the changes with William Schneider of NASA OMSF the same day and Schneider was to present the changes to George E. Mueller and Samuel C. Phillips for approval.
The two-burn lunar orbit insertion (LOI) was an operational procedure to desensitize the maneuver to system uncertainties and would allow for optimization of a lunar orbit trim burn. The procedure would be used for lunar orbit and lunar landing missions. The spacecraft lunar-adapter spring-ejection system was required to ensure adequate clearance during separation of the LM/CSM from the S-IVB/instrument unit and would be used on the first manned CSM/LM mission.
Ltr., Robert R. Gilruth to Phillips, "Proposed changes to Lunar Orbit Insertion and LM extraction on the Lunar Mission Flight Profile," April 10, 1968.
April 10A TV camera would be carried in CM 101 on the first manned Apollo flight, Apollo Program Director Samuel C. Phillips, wrote the ASPO Manager (confirming their discussions). Incorporation and use of the camera in CM 101 would conform to the following ground rules:
April 12A number of decisions were made at the completion of a parachute review at Northrop-Ventura:
April 12Apollo Special Task Team Director Eberhard Rees wrote Dale D. Myers at North American Rockwell: "As you are well aware, many manhours have been spent investigating and discussing the radially cracked insulation on wire supplied by Haveg Industries. On March 27, 1968, NR [North American Rockwell] made a presentation on this problem and reported the action taken to correct the problem and to prevent defective wire from being used. . . . It was disturbing to me to learn that with all the additional actions. . . cracked insulation again was found, this time during the manufacture of harnesses for C/M 110, 111, 112 and S/M 111. This raises the question as to whether the total problem has really been identified and whether or not sufficient corrective action has been taken. . . ." Rees then requested a reply to 10 questions he submitted as to reasons for the problem and possible actions that might be taken.
Ltr., Rees to Myers, April 12, 1968.
April 16A meeting at MSC with Irving Pinkel of Lewis Research Center and Robert Van Dolah of the Bureau of Mines reviewed results of boilerplate 1224 tests at 11.4 newtons per square centimeter (16.5 pounds per square inch) in a 60-percent-oxygen and 40-percent-nitrogen atmosphere. (Both Pinkel and Van Dolah had been members of the Apollo 204 Review Board. Others attending were Jerry Craig, Richard Johnston, and George Abbey, all of MSC; and George Gill and Fred Yeamans, both of GE.) The total boilerplate 1224 test program was reviewed as well as test results at 11 newtons per sq cm (16 psi) in 60 percent oxygen and 40 percent nitrogen and also in 95 percent oxygen. Both Pinkel and Van Dolah agreed with the MSC position that the tests proved the spacecraft was qualified for testing and flight in the 60-40 environment. They expressed the opinion that the 60-40 atmosphere seemed a reasonable compromise between flammability, physiological, and operational considerations.
Memo, Chief, Thermodynamics and Materials Br., to Chief, Systems Engineering Div., "Review of BP 1224 test data with I. Pinkel and R. Van Dolah," April 19, 1968.
April 17MSC Engineering and Development Director Maxime Faget reported to George Low that his directorate had investigated numerous radiation detectors, ionization particle detectors, and chemical reactive detectors. The directorate had also obtained information from outside sources such as the National Bureau of Standards, Mine Safety Appliances, Parmalee Plastics, Wright-Patterson Air Force Base, and the Air Force Manned Orbiting Laboratory organization. None of the methods investigated could meet the stated requirements for a spacecraft fire detection system.
Memo, Faget to Low, "Status of development effort for fire detection system," April 17, 1968.
April 17MSC Director Robert R. Gilruth recommended to NASA Associate Administrator for Manned Space Flight George E. Mueller that MSC's Sigurd A. Sjoberg be approved as the U.S. Representative to the International Committee for Aeronautics of the Fdration Atique Internationale. Robert Dillaway of North American Rockwell, who had been serving as U.S. Representative, had accepted a position with the Navy and recommended Sjoberg to James F. Nields, President of the National Aeronautic Association, and to Major General Brooke F. Allen, Executive Director of the Association, and they had concurred in the recommendation. NASA Hq. approved the request May 20.
Ltrs., Gilruth to Mueller, April 17, 1968; Mueller to Gilruth, May 20, 1968.
April 18Two major requirements existed for further service propulsion system (SPS) testing at the Arnold Engineering Development Center (AEDC), ASPO Manager George M. Low advised Apollo Program Director Samuel C. Phillips. First, the LM docking structure was marginal at peak SPS start transient. While evaluation of the redesigned docking mechanism was under way, final hardware design and production could not be completed until positive identification of the start transient was made through the AEDC test series. Secondly, a modified engine valve had been incorporated into the SPS for CSM 101, which thus necessitated further certification testing before flight (comprising sea-level static firings, simulated altitude firings, and component endurance tests). Low emphasized the need to complete this testing as soon as possible, to isolate any potential problems.
Ltr., Low to Phillips, April 18, 1968.
April 22ASPO Manager George M. Low advised top officials in Headquarters, MSFC, and KSC that he was recommending the use of 100 percent oxygen in the cabin of the LM at launch. MSC had reached this decision, Low said, after thorough evaluation of system capabilities, requirements, safety, and crew procedures. The selection of pure oxygen was based on several important factors: reduced demand on the CSM's oxygen supply by some 2.7 kilograms; simplified crew procedures; the capability for immediate return to earth during earth-orbital missions in which docking was performed; and safe physiological characteristics. All of these factors, the ASPO Chief stated, outweighed the flammability question. Because the LM was unmanned on the pad, there was little electrical power in the vehicle at launch and therefore few ignition sources. Further, the adapter was filled with inert nitrogen and the danger of a hazardous condition was therefore minimal. Also, temperature and pressure sensors inside the LM could be used for fire detection, and fire could be fought while the mobile service structure was in place. As a result, Low stated, use of oxygen in the LM on the pad posed no more of a hazard than did hypergolics and liquid hydrogen and oxygen.
Ltr., Low to Samuel C. Phillips, R. O. Middleton, KSC, and Arthur Rudolph, MSFC, April 22, 1968.
April 22MSC Director Robert R. Gilruth observed that the Engineering and Development Directorate would be conducting two thermal-vacuum test programs during the next several months, following the April 9 shipment of the Block II thermal vacuum test article 2TV-1 to MSC from Downey. (The second test article was the LM counterpart, LTA-8.) Both programs were of major importance, Gilruth told his organization. However, because the 2TV-1 test program directly supported - and constrained - the first manned Apollo mission, he said that, in the event of any conflict between the two test programs, 2TV-1 had clear priority.
Memo, Gilruth to distr., "Program Priority," April 22, 1968.
April 23ASPO Manager George M. Low requested Joseph N. Kotanchik to establish a task team to pull together all participants in the dynamic analysis of the Saturn V and boost environment. He suggested that Donald C. Wade should lead the effort and that he should work with George Jeffs of North American Rockwell, Tom Kelly of Grumman and Wayne Klopfenstein of Boeing, and that Lee James of MSFC could be contacted for any desired support or coordination. The team would define the allowable oscillations at the interface of the spacecraft-LM adapter with the instrument unit for the existing Block II configuration, possible changes in the hardware to detune the CSM and the LM, and the combined effects of pogo and the S-IC single-engine-out case. Low also said he was establishing a task team under Richard Colonna to define a test program related to the same problem area and felt that Wade and Colonna would want to work together.
Memo, Low to J. N. Kotanchik through M. A. Faget, "CSM/LM/SLA dynamic analysis," April 23, 1968.
April 27NASA Administrator James E. Webb approved plans to proceed with preparation of the third Saturn V space vehicle for a manned mission in the fourth quarter of 1968. The planned mission was to follow the unmanned November 9, 1967, Apollo 4 and April 4, 1968, Apollo 6 flights, launched on the first two Saturn V vehicles. NASA kept the option of flying another unmanned mission if further analysis and testing indicated that was the best course. Engineers had been working around the clock to determine causes of and solutions to problems met on the Apollo 6 flight.
NASA News Release 68-81, "Manned Apollo Flight," April 29, 1968.
April 27ASPO Manager George M. Low explained to the Apollo Program Director the underlying causes of slips in CSM and LM delivery dates since establishment of contract dates during the fall of 1967. The general excuse, Low said, was that slips were the result of NASA-directed hardware changes. "This excuse is not valid." He recounted how NASA-imposed changes had been under strict control and only essential changes had been approved by the MSC Level II Configuration Control Board (CCB). For early spacecraft (CSM 101 and 103 and LM-3), the CCB had agreed some six months earlier that only flight safety changes woul be approved. To achieve firm understandings with the two prime spacecraft contractors regarding the responsibilities for schedule slips, Low had asked MSC procurement expert Dave W. Lang to negotiate new contract delivery dates based on changes since the last round of negotiations. These negotiations with North American Rockwell were now completed. (Talks at Grumman had not yet started.) Despite a leniency in the negotiations on early spacecraft, Low said, results clearly indicated that most schedule delays were attributable to North American and not to NASA. On 2TV-1, for example, delivered two months late, analysis proved that less than three weeks of this delay derived from customer-dictated changes. The situation for CSM 101, though not yet delivered, was comparable. Moreover, a similar situation existed within the LM program: LM-3 would be delivered some five weeks behind the contract date, with only two of those weeks caused by NASA changes. Despite this attempt to set the record straight regarding schedule slippages, Low stressed that he did not wish to be over critical of the contractors' performance. Because schedules over the past year had been based on three-shift, seven-day-per-week operation, little or no time existed for troubleshooting and "make work', changes that inevitably cropped up during checkout activities.
Ltr., Low to Samuel C. Phillips, NASA Hq., April 27, 1968.
April 30ASPO was implementing actions recommended by Edgar M. Cortright following his review of Apollo subsystem programs and visits to Apollo subcontractors (see March 12), ASPO Manager George Low advised Apollo Program Director Sam Phillips. These additional steps included further testing of hardware (including "augmented" testing to define nominal and off-nominal operating conditions better); better NASA overseeing of certification test requirements and results; a reexamination by the Crew Safety Review Board of system operating procedures, with emphasis on crew operations; closer subcontractor participation in program decisionmaking, chiefly through the proposed augmented tests and product improvement program; and greater emphasis at the subcontractor plants on the manned flight awareness program.
Ltr., Low to Phillips, "Apollo Subcontractor Review," April 30, 1968.