During reentry, the American crew was accidentally exposed to
nitrogen tetroxide gas. The potentially harmful nitrogen
tetroxide gas resulted from inadvertent reaction
control system (RCS) firings and entered the
command module through the cabin pressure relief valve,
which was opened during landing. As a therapeutic
measure,the crew was given 100% oxygen for 15 to 20
minutes aboard the recovery vessel. All crewmen complained
of chest tightness, coughing, a burning
sensation when breathing and an inability to
inhale deeply, but made a full
recovery from the gas exposure. The therapy
given to the crew potentially affected two life sciences
experiments that were conducted by preflight and
postflight blood sampling and analysis. Despite this
impact, scientifically useful results were obtained in these
experiments.
Seven life sciences experiments were conducted during the Apollo-Soyuz flight. Three experiments examined particle radiation effects on living cells, three experiments examined the effects of space flight on the human immune system, and one examined the vestibular system of killifish. More specifically, the effects of cosmic particles on living cells were examined by the observation of the light flash phenomenon that occurs to astronauts during different orbital orientations. The Biostack III German experiment extended the studies of previous flights on the effects of highly charged and energetic (HZE) particles on biological organisms by evaluating the growth and development of plant seeds and animal eggs that were contained in the biostack. The zone-forming fungi experiment, a joint U.S. and U.S.S.R. experiment, was an attempt to observe the real-time mutations caused by HZE particle exposure that might occur in a ring of growing fungal cells.
Microbial exchange of marker microorganisms
between cosmonauts and astronauts, another
joint U.S. and U.S.S.R. experiment, was examined to
determine the level of
cross-contamination as a way to understand the balance between the
immune system and infectious microorganisms in the space
environment.
In addition,preflight and postflight blood samples were taken from
astronauts to examine invitro lymphocyte and
polymorphonuclear leukocytes
response as indicators of cellular immune function.
The swimming behavior of the killifish was filmed during various stages of the mission to understand how microgravity effects hatchlings. Killifish hatching and orientation was observed to determine the function and development of the vestibular system and calcium metabolism as it related to otolith development.
The material processing experiments conducted on the Apollo-Soyuz Test Flight consisted of 11 experiments, two of which were biological processing and nine of which were considered solid materials processing. The biological materials processing experiments consisted of separating a mixture of biological cells by gelelectrophoresis to observe how cells separate without the limitations of sedimentation and thermal convection that normally occur during electrophoresis on the ground. The materials processing experiments were divided into two groups, namely high-temperature and low-temperature processing. The high temperature processing included the melting and solidifying ofseven sets of material samples in an electric furnace. The low temperature processing consisted of one experiment that attempted to grow crystals in water at ambient temperatures.
The space sciences experiments that were conducted on the Apollo-Soyuz mission included five astronomy and five Earth studies investigations. The astronomy experiments ranged from soft x-ray observations which focus on objects deep in the galaxy to the crystal activation experiments which had implications for the application of crystal detectors in gamma-ray astronomy. The Earth studies included the ultraviolet absorption experiment which investigated the atomic composition of the upper atmosphere to the study of the Earth's subsurface structure by means of two variations of gravity-field measurements. In addition, the Earth observation and photography experiment examined the surface of the Earth and its land and water regions.
