Astronauts and lunar scientists alike had chafed under the requirement to quarantine spacecraft crews and lunar samples until it could be proved that no infectious organisms had been brought back from the moon. Early in 1970 the Interagency Committee on Back Contamination (ICBC) reviewed quarantine requirements in light of the results from the first two Apollo missions. Considering the conditions that had been found to exist on the moon-and probably had existed for billions of years - the requirement for quarantine now appeared superfluous. After lengthy discussion, the committee agreed to recommend to the NASA administrator that crew quarantine be discontinued. They believed, however, that biological examination of the lunar samples should be continued and that biological containment practices in the lunar receiving laboratory should continue, since among other things they assured the integrity of the samples. It was agreed that the Space Science Board would be advised of this recommendation.79
In February 1970 the Space Science Board discussed the matter and found no reason to discontinue quarantine for Apollo 13, which was to fly in two months, since it was targeted for a highland site that was different from the mare sites sampled by Apollo 11 and 12. Nonetheless it agreed with the ICBC that crews on future missions need not be quarantined unless anticipated differences in landing sites seemed to require it.80
After the aborted flight of Apollo 13, the quarantine remained in force for 14, since it was scheduled to take a deep lunar core sample, which might be different from surface samples.81 So Alan Shepard, Ed Mitchell, and Stuart Roosa spent their time in the quarantine area of the Lunar Receiving Laboratory, the last lunar explorers to do so. When no further evidence of exotic diseases or organic material appeared, the requirement was finally revoked, although the ICBC would continue to function through Apollo 17.82
79. Earl H. Arnold, "Minutes, Interagency Committee on Back Contamination, January 15, 1970."
80. Space Science Board, National Academy of Sciences, "Report of Meeting on Review of Lunar Quarantine Program, February 17, 1970."
81. J. W. Humphreys, Jr., to Dir., Apollo Program, "Quarantine for Apollo 14 and Subs," July 16, 1970.
82. Humphreys, TWX to multiple addressees, "Discontinuation of Lunar Quarantine," Apr. 28, 1971; Myers to MSC Director, "Decision to Terminate Quarantine," May 10, 1971 with encl., "Decision to Terminate Quarantine Under NMI 1052.90 (Attachment A, Change 1, 2)," signed by George M. Low, Apr. 26, 1971.