The Apollo Spacecraft - A Chronology.|
Part 2 (J)
Recovery, Spacecraft Redefinition, and First Manned Apollo Flight
March 1MSC had decided not to static-fire the service modules of Block II spacecraft before flight (specifically, spacecraft 101), ASPO advised NASA Hq. The decision was based on successful completion of the spacecraft 102 static firing, evaluation of the test history on the service propulsion system, and a review by a joint MSC-MSFC team that came out flatly against any such static firings at KSC and acceded to such tests at White Sands only under Houston's strict authority. During subsequent discussions in Houston (notably a February 19 meeting with the MSFC contingent), program planners rejected such firings at White Sands because the additional transportation and handling might degrade reliability of the hardware - exactly the opposite of what was being sought.
Ltr., ASPO Manager George M. Low to Apollo Program Director Samuel C. Phillips, March 1, 1968.
March 1John D. Stevenson, Director of Mission Operations, NASA OMSF, requested that MSC Flight Operations Director Christopher C. Kraft, Jr., prepare an analysis of the potential terrestrial threat posed by an uncontrolled reentry of the Apollo 6 spacecraft. (Surviving debris presented a possible danger should a service propulsion system failure or other malfunction preclude a controlled reentry.) Stevenson asked Kraft to include the debris hazard in MSC's Abort and Alternate Mission Study for Apollo 6 then under preparation.
Ltr., Stevenson to MSC, Attn: Kraft, "Terrestrial Threat from Apollo 6 CSM Control Failure," March 1, 1968.
March 4The MSC Flammability Review Board met to assess results of the CSM flammability tests conducted on boilerplate 1224. The Board unanimously recommended using a 60-percent-oxygen and 40-percent-nitrogen atmosphere in the spacecraft cabin during launch, but continued use of a pure oxygen atmosphere at pressure of 4.1 newtons per square centimeter (6 pounds per square inch) during flight. Members concluded that this mixed-gas environment offered the best protection for the crew on the pad and during launch operations, while still meeting physiological and operational requirements. During the final stages of the flammability test program, tests had indicated that combustion characteristics for the 11-newtons-per-sq-cm (16-psi), 60-40 atmosphere and for the 4.1-newton pure oxygen atmosphere were remarkably similar. Also, full-scale trials had demonstrated that in an emergency the crew could get out of the spacecraft quickly and safely.
Memo, George E. Mueller to Administrator, "Manned Space Flight Weekly Report - March 11, 1968."
March 6-7Design Certification Reviews of CSM 101 and LM-3 were held at MSC. Significant program-level agreements reached included validation of a 60-percent-oxygen and 40-percent-nitrogen cabin atmosphere during launch (see March 4); reaffirmation of the February 6 Management Council decision that a second unmanned LM flight was not required; and the conclusion that, in light of successful static firing of the 102 service propulsion system and subsequent analysis, a static-firing of the 101 system was not required.
March 8Apollo Special Task Team Director Eberhard F. M. Rees wrote Dale D. Myers, Apollo CSM Program Manager at North American Rockwell, to convey the concern of ASPO Manager George M. Low and others over the status of the S-band high-gain-antenna system. (Of all the subsystems in the spacecraft, that antenna seemed to face perhaps the toughest technical and schedule problems.) On December 14, 1967, Rees had visited the subcontractor's plant (Dalmo Victor) at Belmont, Calif., and had heard optimistic status reports on the entire system, including quality control and delivery schedules. Shortly thereafter, when Dalmo Victor began quality testing, the company encountered serious technical difficulties and the delivery schedule, as Rees put it, "collapsed completely." He then recounted several efforts by analytical teams to pinpoint the technical problems and to put the program back into shape (including reviews in mid-February and again on March 1, when very little progress could be seen). This record of inability to remedy technical problems, said Rees, indicated a serious weakness among Apollo contractors regarding visibility of their programs as well as their analytical engineering capability.
Ltr., Rees to Myers, March 8, 1968.
March 8NASA technicians at KSC completed the flight readiness test for Apollo 6. The two-day event was delayed several days because of difficulties in modifying the service propulsion system tank skirt. With that significant launch-preparation event completed, program officials were reassessing the launch date in light of work remaining on the vehicle.
Memo, George E. Mueller to Administrator, "Manned Space Flight Weekly Report - March 1 1. 1968."
March 11North American Rockwell technicians at Downey completed integrated system testing on 2TV-1, the CSM thermal vacuum test vehicle. Shipment of the test article to MSC was scheduled for the end of March.
Memo, George E. Mueller to Administrator, "Manned Space Flight Weekly Report- March 15, 1968," March 18, 1968.
March 12Edgar M. Cortright, NASA Deputy Associate Administrator for Manned Space Flight, reported on the results of a thorough review of Apollo subcontractors made during January and February at the request of George E. Mueller. Cortright's review, coordinated with Apollo Program Directors in Washington and Houston, included detailed analysis of subsystem programs and on-site assessment of technical problems, schedule patterns, and testing programs. While favorably impressed with what he had found in general, he cited a number of what he termed "disturbing" conditions: most subsystems were facing hardware delivery schedule problems; many open failures existed; most qualification tests obviously would run beyond flight hardware delivery dates, requiring change-outs at KSC; several of the major subcontractors' difficulties had been compounded by lack of visibility of the overall spacecraft program (those "subs," he said, could have benefited from more attention by the "primes" and from allowing them a role in decision-making affecting their subsystems). Also, Cortright concluded that NASA itself could make more efficient use of subsystem managers and get them more deeply involved in the life of their respective programs. As a remedy to improve the total subsystem picture, Cortright recommended additional subsystem testing (and closer scrutiny by NASA of those tests); a reexamination of the entire Apollo system to determine any procedural errors in operating the subsystems that could result in failure of a subsystem; more contractor involvement in decision-making by both NASA and the primes; and greater emphasis on the manned space flight awareness program.
Memo for record, Cortright, "Apollo subcontractor review," March 12, 1968.
March 14NASA announced to the public that program officials had decided to use a 60-percent-oxygen and 40-percent-nitrogen atmosphere in the Apollo spacecraft cabin while on the launch pad (and to retain the pure-oxygen environment in space). This technical decision - because of the earlier tragedy with Apollo 204 over a year earlier - was subjected to closer public scrutiny than perhaps any comparable decision in the history of the U.S. space program. The change affected only ground operations and support equipment and did not necessitate any major changes in the spacecraft itself. Exhaustive testing of the redesigned interior of the vehicle since October 1967 had demonstrated that the risk of fire inside the spacecraft had been drastically reduced. Hardware changes inside the cabin, spokesmen said, had minimized possible sources of ignition and materials changes had vastly reduced the danger of fire propagation.
NASA News Release 68-47, "Apollo Spacecraft Cabin Atmosphere," March 14, 1968.
March 18The MSC Structures and Mechanics Division reported to ASPO Manager George M. Low that additional verification of the spacecraft 020 reaction control system (RCS) pressure vessels would not be required. Using pressure vessel histories received March 14 and the previous propellant temperature restriction of 297 kelvins (75 degrees F) maximum, fracture mechanics analyses showed:
March 18Samuel C. Phillips, NASA Apollo Program Director, expressed concern to ASPO Manager George Low that relaxed review procedures on LM-4 and LM-5 might tend to delay identification and resolution of problems. Phillips had understood that the LM-4 Phase II Customer Acceptance Readiness Review (CARR) had been rescheduled and that the LM-5 Phase I and Phase II CARRs might be combined. He requested that every possible effort be made to get a good Phase II review on LM-4 and separate Phase I and Phase II reviews on LM-5.
Ltr., Phillips to Low, March 18, 1968.
March 19ASPO Manager George Low emphatically rejected North American Rockwell's suggestion of added spacecraft delivery delays. Responding to a February letter from North American CSM Program Manager Dale D. Myers - suggesting further slips in delivery of 2TV-1 and spacecraft 101, 103, and 104 - Low reminded Myers that at the close of the Configuration Control Board meeting on February 23 he had cited a mid-April target for delivery of CSM 101. Since that time, Low said, KSC had been actively preparing for an early summer launch based on that mid-April delivery, and circumstances therefore made that date most important. Moreover, North American must deliver CSM 103 by the end of June 1968 in order to ensure meeting Apollo's end-of-the-decade goal. He reminded Myers that he had pursued this point on several occasions with him and with William Bergen. They both had told Low that they had found ways to deliver 103 within that time frame, and Low now suggested that this target date be made a firm commitment in the official Apollo schedules. At the earliest possible date, Low concluded, MSC and North American must establish firm contractual baselines for delivery schedules. Until then present delivery dates remained valid. He admitted that some schedule slips had resulted from NASA-dictated changes and that the schedules should be adjusted accordingly. The remaining delays, however, Low attributed directly to the company's inability to meet projected commitments. The contract was changed to call for an April 1968 delivery for CSM 101 and a June 1968 delivery for CSM 103.
Ltr., Low to Myers, March 19, 1968; Part IV Contract NAS9-150.
March 21The lunar landing research vehicle was operating and training was being conducted, MSC Director Robert R. Gilruth wrote Langley Research Center's Acting Director Charles J. Donlan. MSC intended to conduct a second class for LLRV pilots and one of the first requirements for checkout was a familiarization program on Langley's Lunar Landing Research Facility. He requested that a program be conducted for not less than four nor more than six MSC pilots between April 15 and May 15.
Ltr., Gilruth to Donlan, March 21, 1968.
March 21MSC asked Grumman to make a thorough review of the amount of nominal, off-nominal, and extended-life subsystem testing of LM production hardware and recommend any additional testing that should be done. The review of performance data was needed, Neal said, to ensure that program officials had sufficient test data to support flight planners and flight controllers during the manned missions.
Ltr., James L. Neal, LM Contracting Officer, MSC, to Joseph G. Gavin, LM Program Manager. Grumman Aircraft Engineering Corp., "Contract NAS 9-1100, Proposal for additional subsystem testing," March 21, 1968.
March 21In an effort to resolve the continuing technical and schedule problems with the high-gain antenna system at Dalmo Victor, Apollo CSM Program Manager Dale D. Myers named a Resident Subsystem Project Manager at the vendor's plant. This change provided a single management interface with Dalmo Victor. The representative had been given authority to call on whatever North American Rockwell resources he might need to accomplish program objectives.
Ltr., Myers to Kenneth S. Kleinknecht, MSC, March 21, 1968.
March 22Eberhard F. M. Rees, Director of the Apollo Special Task Team at North American Rockwell, wrote to the company's CSM Program Manager Dale D. Myers to express his concern over persistent problems with leaks in the ball valves for the service propulsion system. Rees doubted that any real progress was being made, stating that the problem persisted despite relaxations in leakage criteria and that qualification failures continued to occur. Rees described a review of the program on March 18 at Aerojet-General Corp. as lacking in factual depth. Also, the company did not appear to be pursuing developmental testing of configurational changes with any degree of vigor. Rees suggested to Myers that his people were on the right track and with management attention the vendor's efforts could be channeled to get some genuine results.
Ltr., Rees to Myers, March 22, 1968, with encl., "Minutes of AGC Ball Valve Presentation," March 18, 1968.
March 23Apollo drogue chute test 99-5 failed at the El Centro, Calif., parachute facility. The drop was conducted to demonstrate the slight change made in the reefed area and the 10-second reefing cutter at ultimate load conditions. The 5,897-kilogram vehicle was launched from a B-52 aircraft at 10,668 meters and programmer chute operation and timing appeared normal. At drogue deployment following mortar activation, one drogue appeared to separate from the vehicle. This chute was not recovered but ground observers indicated the failure seemed to occur in the riser or vehicle attachment. The second drogue remained on the vehicle but seemed to slip in the reefed state. This chute was recovered and inspection confirmed the canopy failure. The Air Force parachute system which was to recover the vehicle also failed in the reefed state.
TWX, George M. Low, MSC, to NASA Hq., Att: Director, Apollo Program Office, March 23, 1968.
March 27ASPO documented its reasons for using nitrogen rather than helium (as the Air Force had done) as the diluent in the Apollo spacecraft's cabin atmosphere, in response to a suggestion from Julian M. West of NASA Hq. Aaron Cohen, Assistant Chief of the MSC Systems Engineering Division, recounted that the Atmosphere Selection Task Team had addressed the question of nitrogen versus helium (regardless of percentage) and had rejected helium because of uncertainty of the compatibility of spacecraft equipment with helium. Further, helium presented the same physiological problems as did nitrogen, and whatever flammabilities advantages helium possessed were extremely small. For all these reasons, Cohen explained, the team had early elected to concentrate on nitrogen- mixed atmospheres.
Memo, George M. Low, MSC, to West, "Selection of nitrogen as a diluent for the Apollo launch atmosphere," March 27, 1968, with encl., memo, Cohen to Low, "Nitrogen selection as a diluent," March 25, 1968.
March 27-28A LM prelaunch atmosphere selection and repressurization meeting was held at MSC, attended by representatives of MSC, MSFC, KSC, North American Rockwell, and Grumman. The rationale for MSC selection of 100 percent oxygen as the LM cabin launch atmosphere was based on three factors: use of other than 100 percent oxygen in the LM cabin would entail additional crew procedural workloads at transposition and docking; excessive risk to crew due to depletion of the CM emergency oxygen consumables would be added; and it would require use of 2.7 kilograms of onboard CM oxygen. Two problems were identified with use of 100 percent oxygen in the LM cabin at launch: LM cabin flammability on the pad and LM venting oxygen into the SLA during boost. If air were used in the LM cabin at launch and the LM vent valve opened during boost, the full CM stored-oxygen capacity would be required to pressurize the LM and LM tunnel for umbilical mating. For a lunar mission, this situation would be similar to that before lunar orbital insertion, but would subject the crew to a condition of no stored oxygen for an emergency. For an earth-orbital mission this situation would be objectionable because CM stored oxygen would be lacking for an emergency entry into the atmosphere. (See also April 22 entry.)
Ltr., Low to addressees, April 17, 1968, with encl., memo, Assistant Chief, Systems Engineering Div. to addressees, "Minutes of LM Repressurization Meeting," April 8, 1968.
March 29Scott H. Simpkinson, Acting Chief of ASPO Test Division, authorized assignment of Boeing-TIE personnel to Downey, Calif., and Bethpage. N.Y., to support test evaluation areas - because of fixed limitations on the number of resident NASA personnel at the prime contractors' locations.
Memos, Simpkinson to Chief, Program Control, "Boeing-TIE support," March 29. 1968.
March 29Samuel C. Phillips, NASA Apollo Program Director, wrote ASPO Manager George M. Low to express concern about two particular technical problems in the Apollo Lunar Surface Experiments Package:
Ltr., Phillips to Low, March 29, 1968.
March 29NASA Hq. asked that MSC consider a variety of lunar photographic operations from orbit during manned landing missions. Cancellation from Apollo of the lunar mapping and survey system had eliminated any specially designed lunar photographic capability; but photography was still desired for scientific, operational, and contingency purposes. Presence of the CSM in orbit during manned landing missions, Headquarters OMSF said, would be a valuable opportunity, however limited, for photographic operations. MSC was asked to evaluate these operations to define whatever hardware and operational changes in Apollo might be required to capitalize upon this opportunity.
Ltr., Samuel C. Phillips, Apollo Program Director, NASA Hq., to Director Robert R. Gilruth. MSC, "Lunar Photography from the CSM," March 29, 1968.