STS-78

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Mission emblem
Mission emblem STS-78
Mission dates
Mission: STS-78
COSPAR-ID : 1996-036A
Crew: 7th
Begin: June 20, 1996, 14:49:00  UTC
Starting place: Kennedy Space Center , LC-39B
Landing: July 7, 1996, 12:36:24 UTC
Landing place: Kennedy Space Center, Lane 33
Flight duration: 16d 21h 47m 45s
Earth orbits: 272
Rotation time : 90.0 min
Track height: 267 km
Orbit inclination : 39.0 °
Covered track: 11.2 million km
Payload: Spacelab
Team photo
From left to right: Terence Henricks, Kevin Kregel, back: Jean-Jacques Favier, Richard Linnehan, Susan Helms, Charles Brady, Robert Thirsk
From left to right: Terence Henricks, Kevin Kregel,
back: Jean-Jacques Favier, Richard Linnehan, Susan Helms, Charles Brady, Robert Thirsk
◄ Before / After ►
STS-77 STS-79

STS-78 ( English S pace T ransportation S ystem) is a mission name for the US space shuttle Columbia ( OV -102) of NASA . The launch took place on June 20, 1996. It was the 78th space shuttle mission and the 20th flight of the Columbia space shuttle.

team

Main team

replacement

Mission description

41 experiments by scientists from eleven nations were carried out in the Spacelab and on the middle deck during the longest shuttle mission to date . The focus was on the life sciences medicine and biology as well as microgravity.

Medical examinations

Research was carried out into the effects of weightlessness on individual muscle and bone tissue. Stress tests were carried out through breathing and pulse measurements and the effects on individual muscle fibers were measured. The reactions of the body, in particular the nervous system, to the progressive muscle wasting were also determined . For this purpose, measurements of muscle activity were made on the hand, arm and leg. With the help of blood samples, the hormone level could be determined. Further investigations concerned the ability of muscles to contract, the relationship between the speed of contraction and the load as well as between the strength of the nerve impulse and muscle contraction , the change in muscle volume during and after space flight , the relationship between body fat and muscle mass and the performance of the skeletal muscles before, during and after space flight . Almost all medical experiments have collected data both on earth and in space. Since there is hardly any physical stress in weightlessness, the formation of new muscle and bone cells is sometimes severely restricted.

The effects of an altered metabolism in different cell types were also studied. Work was carried out on the development of a treatment method against calcium breakdown in the bones. For this purpose, a rare calcium isotope was administered, the deposition of which in the bones was measured after returning to earth. The calcium preparation was first taken 10 days before the flight and the last time 7 days after landing. The relationship between energy consumption and calorie intake was also investigated with the help of rare isotopes . A higher energy consumption can lead to the collapse of protein reserves in the muscles. The energy expenditure was measured by determining the isotopic composition in the urine and saliva of the test subjects. For this purpose, comparative studies were carried out under load in space and on earth as well as at rest.

Breath tests with air and a special test gas were carried out to check lung function. The movements of the chest were measured with a specially developed belt. Here, too, comparative data was collected before and after the flight. Changes in the biorhythm were detected by recording body temperature over a whole day, brain waves, eye movements and muscle contractions during sleep and using urine samples . The scientists were also interested in the cognitive performance of space travelers at different times of the day. Therefore, recognition and thinking tests were carried out with a laptop computer. The speed and accuracy of the solution to the given tasks should enable statements to be made about how the alternation of work and relaxation phases can positively influence the performance of the astronauts, even during longer space flights.

Finally, equilibrium studies were carried out. Without the effect of gravity, the vestibular organ in the inner ear is flooded with stimuli. The body of most space travelers reacts to this with nausea and decreased performance. An adjustment usually takes several days. During the Columbia mission, special measuring devices were used to measure and record the movements of the eyes, head and upper body at the beginning of the mission, after a few days and shortly before the return to earth. This was to record how fast the adjustment process takes place. In a second experiment on this problem area, the astronauts wore a cyber helmet on whose screens they were shown moving objects. They should follow them with their eyes. The movements of the head and the eye coordination were recorded.

Biological experiments

Damage in the timber industry occurs when trees suddenly grow crooked for no apparent reason. This creates inferior wood. Using pine seedlings without the influence of gravity, it was investigated what exactly goes on in the cells in such a case. Malformations were documented photographically.

Embryonic development was studied using the example of the Medaka fish . The differences between developments in space and on earth were of particular interest. For this purpose, the 36 embryos in various stages of development were frozen. The exact examination takes place only after the flight.

The role of corticosteroids in bone loss during spaceflight was determined by measuring bone mass, new bone formation and bone cell activity. For this purpose, 12 laboratory rats were kept in two modules on the middle deck of the Columbia.

Microgravity research

In the Bubble, Drop and Particle Unit (BDPU), drops or bubbles of different sizes can be placed in sample containers that are filled with a liquid. By varying the temperature, pressure and electrical fields, the behavior of the inclusions can be studied in different situations. In particular, melting, solidification, evaporation, condensation and flow processes were observed. The disruption of crystallization by gas bubbles, the independent separation of individual components in substance mixtures during melting or solidification as well as the formation and collapse of vapor bubbles when liquids or gas inclusions are locally heated or cooled were investigated. The evaporative cooling of small components in weightlessness and the stability of strips of dielectric liquids within an electric field were also researched. Liquids such as motor or silicone oil change their electrical properties minimally. If they are pulled apart at the ends, the liquid film will later tear in the electric field ( electrodynamics of liquid bridges). In the BDPU, experiments were also carried out on the movement of bubbles in a liquid contained in a container that is heated on one side and cooled on the other. This results in differences in surface tension , which influence the movements of the bubbles. The surface tension is also the cause of turbulent convection flows in multilayered liquid films of different temperatures. Methanol was used, which was located between a cold and a warm octane layer. By observing the flow velocities of all three layers, it was determined at which temperature values ​​the flow destabilized (Marangoni convection). Finally, the movement of bubbles and drops in a liquid was observed at different temperatures. The main focus of research was the mutual influence of the 6 to 10 drops or bubbles that were injected with each test run.

Crystallization experiments are carried out with the Advanced Gradient Heating Facility (AGHF). The edge of the solidification zone can be marked by a current pulse (Pektier pulse marking). On earth, the solidification fronts can then be determined in cross-sections of the crystals produced. This enables the growth rate to be determined exactly. A total of 6 examinations were carried out. A comparative study was carried out on the formation of porous and dendritic (tree-like) crystals of an aluminum alloy in weightlessness and under normal gravity. Porous crystals are formed with rapid cooling, dendritic crystals with very rapid shock cooling. The subject of research was the border area between the two types of crystallization. The crystallization of alloys that cannot be mixed on earth (aluminum and indium samples), the effects of convection (surface current ) on the interfacial curvature during the growth of gallium- indium- antimony id crystals, the formation of an elongated one were also investigated or round crystal grain depending on the temperature and other factors in aluminum-copper alloys and the inclusion or displacement of ceramic particles ( zirconium ) at the interfaces of solidifying metals (aluminum or aluminum-nickel alloy). If the particles are incorporated into the crystal structure, improved properties often result, such as higher strength and elasticity . The conditions that are favorable for installation were also of interest. Such processes were simulated on earth with organic substances and polystyrene beads.

As with every flight, there was also a facility for the production of protein crystals on board. The experiments are controlled from Earth ( TeleScience ), the astronauts only have to switch the complex on. In this way, around 5,000 images of crystallization processes came to earth. The crystals themselves were analyzed using special X-ray methods after they returned to Earth. The STS-78 mission synthesized the receptor for the epidermal growth factor EGF and investigated the crystallization of cyanine components for the development of improved anti-cancer drugs. Other samples contained RNA molecules, lysozymes , cell nucleus components , photosystem I, bacteriorhodopsin, the apoptosis protein CcdB and sulfur-containing alcohol dehydrogenase. The investigations are intended to contribute to the development of novel drugs and to identify the most favorable conditions for the production of particularly pure and regular protein crystals.

Disturbances in the crystal structure can occur due to the minimal accelerations caused by engine ignitions, the braking effect of the upper atmosphere and the movements of space travelers. Since they cannot be avoided, they are measured very precisely with three systems. SAMS records short-term accelerations, OARE records longer lasting ones. Both experiments are standard equipment on the shuttle. The Microgravity Measurement Assembly (MMA) is a sensor network that is installed in Spacelab and that reliably measures all accelerations.

The routine experiments on board included the SAREX amateur radio system , the photographic documentation of special events on earth (e.g. forest fire in Arizona) and the testing of the new FES heat regulation system. Particular emphasis was placed on the use of a video conference system, with which consultations between the astronauts and the scientists on earth about the progress and possible changes to the experiments could take place directly. After a successful flight, the Columbia landed on the grounds of the Kennedy Space Center with only minor and solvable technical problems . At the request of the scientists on the ground, the planned flight duration was extended by one day.

See also

Web links

Commons : STS-78  - album with pictures, videos and audio files