Where No Man Has Gone Before: A History of Apollo Lunar Exploration Missions

FINAL PREPARATIONS: 1968

Problems with Back-Contamination Control

The receiving laboratory was only part of the scheme for preventing contamination of the earth by alien organisms. Between the spacecraft floating on the Pacific Ocean and the laboratory in Houston was a long chain of events that offered several chances to contaminate the environment. Early in 1968, spumed by expressions of concern by scientists outside the government, the Interagency Committee on Back Contamination (ICBC) revived the question of whether lunar contaminants could be completely prevented from escaping into the biosphere during recovery operations, particularly between the floating command module and the mobile quarantine facility aboard the recovery ship. For two years the committee had been uneasy about this problem, and at its February meeting the chairman opened the discussion once more. The committee asked MSC's landing and recovery division to provide

a detailed discussion on the return lunar mission [focusing on] containment countermeasures on the lunar surface, in the Lunar Module (LM) ascent stage, during LM-CM transfer, during CM earth return, splashdown, retrieval, operations onboard the recovery vessel, transfer into the mobile isolation unit, and delivery and transfer into the LRL.
Committee members also wanted details of MSC's contingency plans for biological containment in case the spacecraft came down outside the primary recovery zone.31

These requests surprised Apollo officials at Houston, who thought those questions had long been settled. Nonetheless, MSC engineers reviewed the subject again at the June meeting of the ICBC, and the committee kept the containment question on its agenda for further study.32 At its October meeting the ICBC reiterated its considered opinion that the recovery crew should attach some type of biological filter to the spacecraft's post-landing ventilation valve, which circulated air through the command module and exhausted it to the outside. When this question had been raised two years before, MSC had demurred, warning that an effective filter would reduce the efficiency of the ventilation system to an unacceptable level and that attaching it to a floating spacecraft was too hazardous to the recovery crew, especially in a rough sea. The committee insisted, however, that development of a filter attachment with a supplemental fan should be "energetically pursued to avoid what could be compromised and untoward decisions."33

When these discussions came to the attention of MSC Director Robert R. Gilruth, he asked for a detailed briefing on the situation and ordered another review of the question.34 Further discussions at MSC reaffirmed the center's basic position that biological isolation garments for the crew [see Chapter 7] constituted the best available containment in view of the difficulties presented by more secure measures. MSC officials did, however, propose to take more stringent precautions against bringing lunar dust into the command module.35 Preliminary discussions of these procedures with an ad hoc committee of the ICBC produced tentative agreement.36

At the full committee meeting, however, agreement could not be reached. MSC presented its plans for minimizing the transfer of lunar dust into the lunar module and thence into the command module, which apparently mollified the ICBC somewhat. But after reviewing the results of a simulation of Apollo 9, which had included the use of the biological isolation garments and other phases of recovery, the committee was convinced that recovery procedures allowed a breach of containment that must be corrected.37 Dr. David Sencer, the ICBC chairman, then wrote a strongly worded letter to Thomas O. Paine, newly appointed NASA administrator,* expressing dismay over MSC's apparent failure to appreciate the problem and make serious efforts to correct it. He pointed out that if recovery procedures allowed lunar organisms to contaminate the earth, the rest of the elaborate (and expensive) chain of quarantine was rendered useless and the space agency would lay itself open to severe criticism by the public and the scientific community. Sencer told Paine that the ICBC had considered recommending that the first mission be delayed so the situation could be corrected, but had decided instead to recommend that a filtration system for the command module be positively required on all future lunar missions - on the first, if possible, but only if it would not delay the mission. The risk of contamination was acceptable only if strict housekeeping procedures were enforced to minimize the amount of lunar dust brought into the command module and if recovery teams were thoroughly trained and required to observe contamination-control measures.38

Sencer's letter produced immediate results. The questions were aired at a Manned Space Flight Management Council meeting on April 9, after which Sam Phillips directed Houston's spacecraft project manager, George Low, to begin immediate action on the ICBC's concerns.39 Low assigned a variety of tasks to various MSC offices: reexamination of the feasibility of adding a biological filter to the postlanding ventilation system, a look at the possibility of maintaining air flow from the command module to the lunar module during crew transfer in lunar orbit, and a study of reinforcing the command module's hoisting ring to allow the spacecraft to be safely lifted onto the recovery ship with the crew still inside.40 Houston reported the early results of its studies to Headquarters two weeks later, then continued to work the problems with a view to submitting concrete proposals to the next interagency committee meeting in early May.41

But time was running short. Plans called for the first lunar landing mission to be launched in July; back-contamination procedures were still not approved, and the receiving laboratory, critical to the program, was still far from ready. Bob Gilruth became uneasy. In early April he put his special assistant, Richard S. Johnston, in charge of all management activities relating to the receiving laboratory and back-contamination procedures, with the full authority of the director's office.42 Johnston had been chief of the Crew Systems Division at MSC for many years before moving up to the post of Special Assistant to the Director, and had built a reputation as a forceful administrator who could get things done.

Johnston's first task was to present a summary of MSC's position on back-contamination problems at the May meeting of the ICBC. Stressing that in MSC's opinion the questions of controlling back-contamination during recovery had been settled earlier, Johnston went ahead to outline MSC's plans in detail. Flight plans called for the astronauts to contain as much lunar dust as possible in the lunar module by vacuuming it off their space suits, then doffing the suits and sealing them in storage bags before returning to the command module.** During the transfer the LM pressure relief valve would be opened and the oxygen flow in the command module would be increased, to maintain a current of gas flowing from the command module to the lunar module, thus minimizing the amount of dust carried into the command module. Tests convinced spacecraft engineers that the command module's environmental control system - specifically the canisters of solid lithium hydroxide that absorbed carbon dioxide - would effectively filter particles (including microorganisms) out of the spacecraft atmosphere during the 63-hour trip back from the moon. Thus only the astronauts would be a potential source of biological contamination, and they could be isolated from the environment by donning the special garments provided for the purpose. Johnston reiterated that adding a biological filter to the command module ventilation system was not necessary and was undesirable. However, MSC would continue to study the implications of adding such a filter to later missions. As for modifying recovery procedures to minimize possible contamination, MSC was unwilling to compromise safety. Hoisting the closed spacecraft to the deck of the recovery ship, as the committee preferred, was not acceptable because of the many hazards involved. Houston officials preferred to leave recovery operations unchanged and to indoctrinate the recovery crews in techniques for minimizing contact between the spacecraft interior and the earth's atmosphere.43

The interagency committee found MSC's proposed procedures generally acceptable, at least for the first mission, but wanted to see the results of more tests before certifying them as effective. Members still felt a need to add the post-landing ventilation filter for the second and subsequent flights. They also thought MSC should pay more attention to contingency recovery procedures, since there was more chance of contamination escaping if the spacecraft had to be picked up by a ship other than the primary recovery vessel.44 But they seemed satisfied that under Johnston's direction the Manned Spacecraft Center was making a stronger effort than before to comply with their recommendations.


* Paine had been deputy administrator under James Webb since early 1968. When Webb retired in October, Paine became acting administrator; he was appointed and confirmed as administrator in March 1969.

** The crew of Apollo 10, after testing the lunar module in lunar orbit, recommended against this procedure. They believed it was unacceptably hazardous because in the cramped lunar module the body movements involved could too easily result in contact with fragile areas, such as the windows. Their recommendation was later accepted by the ICBC. Donald K. Slayton to Special Asst. to the Dir. and Mgr., Apollo Spacecraft Program, "Suit Doffing in LM," June 2, 1969; Richard S. Johnston to Dir., Flight [Crew] Operations, same subj., June 11, 1969.


31. John E. Pickering, "Minutes, Interagency Committee on Back Contamination, 8-9 Feb. 1968."

32. Idem, "Minutes, Interagency Committee on Back Contamination, 11 June 1968."

33. Idem, "Minutes, Interagency Committee on Back Contamination, 17-18 Oct. 1968."

34. Richard S. Johnston to C. C. Kraft, M. A. Faget, and C. A. Berry, "Apollo Back Contamination," Nov. 8, 1968.

35. Johnston to multiple addressees, "Back-Contamination program review," Jan. 16, 1969; "ICBC Meeting at MSC on March 28 and 19," Mar. 18, 1969.

36. Gilruth to Maj. Gen. J. W. Humphreys, Jr., Mar. 19, 1969.

37. Pickering, "Minutes, Interagency Committee on Back Contamination, 28-29 March 1969."

38. David J. Sencer to Thomas O. Paine, Apr. 7, 1969.

39. S. C. Phillips, TWX to MSC, attn.: G. M. Low, "Biological containment on 'G' mission prior to entry into MQF," Apr. 10, 1969.

40. Ibid.; Low to multiple addressees, "Apollo Back Contamination Action Items," Apr. 14, 1969; Low to Phillips, "Apollo Back Contamination Action Status," Apr. 15, 1969.

41. Low to Phillips, "Transmittal of Summary Report and Actions from Back Contamination LDX Conference Held April 21, 1969," Apr. 24, 1969, with encl., Low to Multiple Addressees, "Back Contamination LDX Conference held April 21, 1969, Between MSC/NASA Headquarters; minutes and action items," Apr. 24, 1969.

42. MSC Announcement 69-60, "Lunar Receiving Laboratory Operations," May 1, 1969.

43. Johnston, draft of MSC position paper on Apollo back contamination program, Apr. 25, 1969.

44. Pickering, "Minutes, Interagency Committee on Back Contamination, 2 May 1969."


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