Compatible Atmospheres

Ed Smylie and his NASA colleagues working on environmental control problems with the Soviets were quite satisfied with their progress. Ilya Vladimirovich Lavrov was present at the Moscow sessions, and it was apparent to the Americans that he had sparked considerable activity on his team's part since the July meeting. With few preliminaries, the October talks tackled the question of spacecraft pressures. The Apollo command module [211] would continue to operate at its standard pressure, 258 mm Hg. But at the Soviets' suggestion, the pressure of the Soyuz would be lowered during the docked portion of the flight to eliminate lengthy pre-breathing periods. While the "most rational decision to make would have been to utilize the same atmosphere with regard to total pressure and partial pressures of oxygen," the Apollo could not have an operational pressure higher than 325 millimeters, and the Soyuz for reasons of fire safety could not have an oxygen content higher than 40 percent. In addition to greatly simplifying the onboard hardware and equipment with which the crews would work, this important Soviet design concession also meant that the transfers between the two ships would be easier, reducing time and procedures.39

Group 5 also discussed the Soyuz life support system and modifications that would be required to lower pressure during the joint phase of the mission. Lavrov indicated that the Soviets had put aside all considerations of using a pressurized oxygen system and instead would modify the existing potassium superoxide oxygen generating system. In addition, they said that they would develop an emergency pressurization system as NASA had suggested. At this meeting, the Americans finally understood that this capability had not been present on earlier Soyuz flights and that in fact the Soviets had never carried any pressurized gases on their spacecraft.40

The specialists also discussed such contingency situations as extravehicular transfer and the return of mixed crews. After reviewing the life support systems of both spacecraft, they came to the conclusion that there was no real need to consider external transfer on this mission, thus eliminating the need for special equipment related to space suits. Return of a crewmember from one nation in the spacecraft of the other was considered a possibility in an emergency situation, but it would have to be accomplished without the use of any supplementary equipment. The Soviets requested more time to study this contingency and agreed to report back in March 1973. Lavrov also indicated that they had definite plans for vacuum chamber tests (similar to the American tests of an early breadboard mockup of the DM) of an orbital module docking module combination. The Americans said they would provide the Soviet team with drawings so they could build a DM boilerplate model for these tests.41

The meeting in Moscow had gone well. From his vantage point on 25 October, Lunney said at a combined debriefing session and ASTP staff meeting in Houston that he had been pleased with their progress. He noted that the Soviets had been well prepared, providing adequate translators, interpreters, and general logistical support for the gathering. Reporting on future activities, he said that Groups 2 and 4 would meet in November, Group 3 would hold tests in December, and the next plenary sessions were scheduled for March 1973 in Houston.42

[212] After getting back to Texas, Lunney and his ASTP team prepared for two major reviews of hardware design with North American Rockwell. On 8 November, the Critical Design Review (CDR) for CSM 111 and the Preliminary Design Review for the docking module and docking system were convened at the contractor's Downey factory. Basically, the CDR was held to conduct a detailed check on the CSM engineering specifications and drawings prior to their release to the production engineers who would then oversee the manufacturing and assembly. The PDR for the docking module and the docking system was another in the series of basic checks on the detailed design tasks related to those pieces of flight hardware. For these reviews, there were 24 teams, each of which was co-captained by a NASA and a contractor employee. Following two days of study, Lunney sat as chairman of a Design Review Board, which met at 8:30 a.m. on the 10th.* 43 While these reviews were in process, Rocco Petrone briefed the Office of Manned Space Flight (OMSF) Management Council on the major accomplishments of the October trip to Moscow and Ed Smith and R. H. Dietz prepared their Working Groups for the sessions slated to begin on 24 November.44

* The members of the board were as follows: from MSC, G. S. Lunney, T. P. Stafford, D. R. Scott, R. A. Colonna, F. Miller, R. P. Burt, E. W. Sievers, and A. Dennett; and from Rockwell, G. Merrick, E. P. Smith, and C. Helms.

39. "Minutes of Working Group No. 5," 9-20 Oct. 1972, in "Minutes of Joint Meeting"; and Lunney, "Minutes, ASTP Staff Meeting, October 25, 1972," 30 Oct. 1972.

40. Lunney, "Minutes, ASTP Staff Meeting, October 25, 1972," 30 Oct. 1972.

41. Ibid.; and "Minutes of Working Group No. 5," 9-20 Oct. 1972, in "Minutes of Joint Meeting."

42. Lunney, "Minutes, ASTP Staff Meeting, October 25, 1972," 30 Oct. 1972.

43. NASA, MSC, "Minutes of Meeting, ASTP CSM 111 Critical Design Review; DM-DS Preliminary Design Review," 8-10 Nov. 1972; and Morris to distribution, memo, "Apollo Soyuz Test Project (ASTP) Design Review," 2 Nov. 1972.

44. NASA, OMSF, "Manned Space Flight Management Council," 8 Nov. 1972.