On 2 August the service module reaction control system engines were inhibited, and the isolation valves closed because of another leak. Acceptable control modes and deorbit and entry procedures were defined, consistent with the constraints imposed by the two reaction control system problems.
The first extravehicular activity was delayed until 6 August because of the crew's motion sickness. The EVA lasted almost six and one-half hours during which time the crew changed the Apollo telescope mount film, deployed the twin-pole sun shield (see 6 August entry), inspected and performed repair work on the S055 (ultraviolet spectrometer) experiment, deployed the S149 (particle collection) experiment, and installed the calibration shield from experiment S230 (magnetospheric particle composition).
A second EVA was performed on 24 August. It lasted 4 hours 30 minutes. The tasks accomplished included installation of a rate gyro package, deployment of a thermal shield material sample, retrieval and replacement of the ATM work station film, temporary stowage of the experiment S149 in the fixed airlock shroud and redeployment at the Sun end, and removal of the aperture door/ramp latch from two ATM experiments.
A third EVA was accomplished in 2 hours and 45 minutes on 22 September. Its purpose was to retrieve the expended film on the ATM solar experiments and experiments S230 and S149. Earth resources experiment package activities included 39 passes with a total of 930 minutes of data. All experiment coverage was normal with the exception of the loss of experiment S193 (microwave radiometer/scatterometer and altimeter) when the antenna failed to operate during data pass 29.
A series of medical experiments was accomplished which assessed the effect of a 59-day space mission on the crewmen. Included were a hematology and immunology program, a mineral balance assessment, an evaluation of the changes in hormonal and associated fluid and electrolyte parameters, the extent of bone mineral loss, the cardiovascular effects utilizing the lower body negative pressure experiment and the vector-cardiogram, and an assessment of metabolic activity.
Four astrophysics experiments were successfully performed: experiment S019 (ultraviolet stellar astronomy); experiment S063 (ultraviolet and visible Earth photography); experiment S149 (particle collection); and experiment S230 (magnetospheric particle composition).
Data were obtained for studies of the habitability and crew quarters and crew activities and maintenance. In addition, several experiment M509 (astronaut maneuvering unit) sequences were performed. The following gives a comparison of the actual crew time in hours:minutes and percent of total time devoted to experiments as opposed to that allocated in the preflight plan. (Hours adjusted to account for increased mission duration).
Medical experiments : Actual - 304:4 / 7 7.2% versus preflight estimate of 291:22 / 6.9%
Apollo telescope mount experiments : Actual - 452:56 / 10.7% versus preflight estimate of 311:01 / 7.3%
Earth resources experiment package : Actual - 223:31 / 5.3% versus preflight estimate of 165:23 / 3.9%
Corollary experiments : Actual - 231:15 / 5.4% versus preflight estimate of 153:45 / 3.6%
Subsystem detailed test objective : Actual - 7:05 / 0.2% versus preflight estimate of 3:49 / 0.1%
Student experiments : Actual - 10:49 / 0.3% versus preflight estimate of 10:06 / 0.2%
Operational (Included sleeping, eating, housekeeping, etc); : Actual - 3017:04 / 70.9% versus preflight estimate of 3314:45 / 78.0%