Spaceflight mission report: STS-79 (original) (raw)
Launch from Cape Canaveral (KSC) and landing on Cape Canaveral (KSC), Runway 15.
A rendezvous and docking with the RussianMir space station and the exchange of astronauts - including the holder of the record for longest space flight ever by a U.S. astronaut - highlighted the flight of Space Shuttle Atlantis on MissionSTS-79.
This was the fourth of nine planned missions toMir between 1995 and 1998 and the first exchange of astronauts. Astronaut ShannonLucid, who was onMir since late March 1996, was replaced onMir by astronaut JohnBlaha. He spent more than four months onMir. He returned to Earth on Space Shuttle MissionSTS-81, launched in January 1997.
STS-79 was the second Shuttle-Mir mission to carry a SPACEHAB module on board, and the first to carry a double module. The forward portion of the double module housed experiments conducted by the crew before, during and after Atlantis was docked to the Russian space station. The aft portion of the double module primarily housed the logistics equipment to be transferred to the Russian space station. Logistics include food, clothing, experiment supplies, and spare equipment forMir.
The currentMir-21 mission began when the cosmonaut crew launched on February 21, 1996, inSoyuz TM-23 and docked with theMir two days later. ShannonLucid joined theMir-21 crew with the March 1996, docking of STS-76. ShannonLucid completed her stay on theMir and returned with theSTS-79 crew. On August 19, 1996 theMir-21 crew was joined by the crew of Mir-22 launched with Soyuz TM-24. TheMir-22 crew will remain onMir after theMir-21 crew returns to Earth in September 1996.
STS-79 was the first shuttle mission to a fully completedMir space station, following the arrival of itsPriroda module. Atlantis carried the 1,821-kilogram (4,010 lb) Orbiter Docking System.
Atlantis' rendezvous and docking with the Russian space stationMir actually began with the precisely timed launch of the shuttle on a course for theMir, and, over the next two days, periodic small engine firings that gradually brought Atlantis to a point eight nautical miles (14.8 km) behindMir on docking day, the starting point for a final approach to the station.
About two hours before the scheduled docking time on Flight Day Three of the mission, Atlantis reached a point about eight nautical miles (14.8 km) behind theMir space station and conducted a Terminal Phase Initiation burn, beginning the final phase of the rendezvous. Atlantis closed the final eight nautical miles (14.8 km) toMir during the next orbit. As Atlantis approaches, the shuttle's rendezvous radar system began trackingMir and providing range and closing rate information to Atlantis. Atlantis' crew also began air-to-air communications with theMir crew using a VHF radio.
As Atlantis reached close proximity toMir, the Trajectory Control Sensor, a laser ranging device mounted in the payload bay, supplemented the shuttle's onboard navigation information by supplying additional data on the range and closing rate. As Atlantis closed in on theMir, the shuttle had the opportunity for four small successive engine firings to fine-tune its approach using its onboard navigation information. Identical to the three priorMir dockings, Atlantis will aim for a point directly belowMir, along the Earth radius vector (R-Bar), an imaginary line drawn between theMir center of gravity and the center of Earth. Approaching along the R-Bar, from directly underneath theMir, allowed natural forces to brake Atlantis' approach more so than would occur along a standard shuttle approach from directly in front ofMir. During this approach, the crew began using a handheld laser ranging device to supplement distance and closing rate measurements made by shuttle navigational equipment.
The manual phase of the rendezvous began just as Atlantis reached a point about a half-mile (900 meters) belowMir. Commander WilliamReaddy flew the shuttle using the aft flight deck controls as Atlantis began moving up towardMir. Because of the approach from underneathMir, WilliamReaddy had to perform very few braking firings. However, if such firings were required, the shuttle's jets were used in a mode called "Low-Z", a technique that uses slightly offset jets on Atlantis' nose and tail to slow the spacecraft rather than firing jets pointed directly atMir. This technique avoids contamination of the space station and its solar arrays by exhaust from the shuttle steering jets.
WilliamReaddy centered Atlantis' docking mechanism with theDocking Module mechanism onMir, continually refining this alignment as he approached within 300 feet (91.4 meters) of the station. At a distance of about 30 feet (9.14 meters) from docking, WilliamReaddy stopped Atlantis and held stationkeep momentarily to adjust the docking mechanism alignment, if necessary. At that time, a final go or no-go decision to proceed with the docking was made by flight control teams in both Houston and Moscow. When Atlantis proceeded with docking, the shuttle crew used ship-to-ship communications withMir to inform theMir crew of the shuttle's status and to keep them updated on major events, including confirmation of contact, capture and the conclusion of damping. Damping, the halt of any relative motion between the two spacecraft after docking, was performed by shock absorber-type springs within the docking device. Mission Specialist CarlWalz had to oversee the operation of the Orbiter Docking System aboard Atlantis.
The Shuttle-Mir link-up occurred at 15:13UTC on September 18, 1996. The hatches opened at 05:40UTC on September 19, 1996 and JohnBlaha and ShannonLucid exchanged places at 11:00UTC. Awaiting JohnBlaha onMir were ValeriKorzun, Mir-22 Commander, and AleksandrKaleri,Flight Engineer. ShannonLucid returned to Earth withSTS-79 and JohnBlaha remained onMir together with the22nd Mir resident crew until STS-81 docked for the next time with the Russian space station.
During her approximately six-month stay onMir, ShannonLucid conducted research in the following fields: advanced technology, Earth sciences, fundamental biology, human life sciences, microgravity research and space sciences. Specific experiments included: Environmental Radiation Measurements to ascertain ionizing radiation levels aboardMir; Greenhouse-Integrated Plant Experiments, to study effect of microgravity on plants, specifically dwarf wheat; and Assessment of Humoral Immune Function During Long-Duration Space Flight, to gather data on effect of long-term spaceflight on the human immune system and involving collection of blood serum and saliva samples. Some of this research was conducted in the newest and finalMir module,Priroda, which arrived at station during ShannonLucid's stay
STS-79 marked the first flight with a double SPACEHAB module, increasing the amount of logistics the shuttle can carry to theMir space station. In addition to the U.S. astronaut exchange, theSTS-79 crew transferred over 4,600 pounds (1,814 kg) of food, water, clothing, personal hygiene supplies, replacementMir hardware components, and U.S. science experiments and supplies to theMir, including five powered experiments (experiments requiring electrical power on the shuttle and immediately onMir).
The Atlantis crew simultaneously received over 2,100 pounds (952 kg) of Russian hardware, empty food and water containers, ESA return science items, and U.S. science hardware, data and specimens from ShannonLucid's science gathering activities during her stay onMir. This was the largest shuttle transfer of logistics to and from theMir to date.
TheMir-21 mission began when the crew launched on February 21, 1996, in aSoyuz vehicle and docked with theMir two days later. ShannonLucid joined theMir-21 crew with the March 24, 1996, docking of STS-76. The return ofSTS-79 concluded a mission of experiments in the fields of advanced technology, Earth sciences, fundamental biology, human life sciences, microgravity, and space sciences. Data also supplied insight for the planning and development of theISS, Earth-based sciences of human and biological processes, and the advancement of commercial technology.
The microgravity environment on a long duration mission provides an ideal opportunity to determine the role gravity plays in molecular mechanisms at a cellular level and in regulatory and sensory mechanisms, and how this affects development and fundamental biological growth. Fundamental biology is also responsible for characterizing the radiation of theMir environment and determining how it may impact station-based science.
Environmental Radiation Measurements: Exposure of crew, equipment, and experiments to the ambient space radiation environment in low Earth orbit poses one of the most significant problems to long term space habitation. As part of the collaborativeNASA/Mir Science program, a series of measurements were compiled of the ionizing radiation levels aboardMir. During the mission, radiation was measured in six separate locations throughout theMir using a variety of passive radiation detectors. This experiment continued on later missions, where measurements will be used to map the ionizing radiation environment ofMir. These measurements will yield detailed information on spacecraft shielding in the 51.6-degree-orbit of theMir. Comparisons were made with predictions from space environment and radiation transport models.
Greenhouse-Integrated Plant Experiments: The microgravity environment of theMir space station provided researchers an outstanding opportunity to study the effects of gravity on plants, specifically dwarf wheat. The greenhouse experiment determined the effects of space flight on plant growth, reproduction, metabolism, and production. By studying the chemical, biochemical, and structural changes in plant tissues, researchers hoped to understand how processes such as photosynthesis, respiration, transpiration, stomatal conductance, and water use are affected by the space station environment. This study was an important area of research, due to the fact that plants could eventually be a major contributor to life support systems for space flight. Plants produce oxygen and food, while eliminating carbon dioxide and excess humidity from the environment. These functions are vital for sustaining life in a closed environment such as theMir or the International Space Station.
Human Life Sciences: The task of safely keeping men and women in space for long durations, whether they are doing research in Earth orbit or exploring other planets in our solar system, requires continued improvement in our understanding of the effects of space flight factors on the ways humans live and work. The Human Life Sciences (HLS) project had a set of investigations for the Mir-22 mission to determine how the body adapts to weightlessness and other space flight factors, including the psychological and microbiological aspects of a confined environment and how they readapt to Earth's gravitational forces. The results of these investigations will guide the development of ways to minimize any negative effects so that crewmembers can remain healthy and efficient during long flights, as well as after their return to Earth.
Assessment of Humoral Immune Function During Long Duration Space Flight: Experiments concerned with the effects of space flight on the human immune system are important to protect the health of long duration crews. The human immune system involves both humoral (blood-borne) and cell-mediated responses to foreign substances known as antigens. Humoral responses include the production of antibodies, which can be measured in samples of saliva and serum (blood component). The cell-mediated response, which involves specialized white blood cells, appears to be suppressed during long duration space missions. Preflight, a baseline saliva and blood sample were collected. While onMir, the crew was administered a subcutaneous antigen injection. In flight and postflight, follow-up blood and saliva samples were collected to measure the white blood cell activation response to the antigen.
Two commercial payloads were transferred toMir onSTS-79 and were retrieved bySTS-81 some four months later:
Biotechnology System (BTS): The Bioreactor rotating wall vessel developed at the Space Cell Biology and Biotechnology Center atNASA's Johnson Space Center was the first of a series of long-duration cell culture experiments. BTS studied the three-dimensional growth of cartilage cells during its 147-day mission.
Material in Devices as Superconductors (MIDAS): The MIDAS experiment developed atNASA's Langley Research Center, Hampton, VA, flew into orbit onSTS-79 and was transferred over to the RussianMir space station for approximately four months. While on theMir, MIDAS measured the electrical properties of high temperature superconductor (HTS) materials during extended space flight and compiled the results in a database for commercial use. HTS materials may be used in a variety of device applications to reduce power requirements and thermal losses. In addition to the development of a database, the MIDAS experiment demonstrated the development of a manufacturing process using integrated superconductor and conventional microelectronics. There have been no previous flights which characterize HTS material in spaceflight at cryogenic temperatures.
Commercial Generic Bioprocessing Apparatus (CGBA): The CGBA hardware was used extensively on short duration Shuttle missions to house a great variety of biotechnology experiments of interest to commercial product development. There are many biotechnology processes which require much longer periods of time than a Shuttle mission can provide. For this reason, the commercial affiliates of BioServe Space Technologies, aNASA Commercial Space Center, are eager to take advantage of the long duration mission which the Shuttle/Mir program provides.
In addition, three experiments made a round-trip voyage aboard Atlantis itself:
Extreme Temperature Translation Furnace (ETTF): The ETTF, which was integrated into the SPACEHAB module, was a new furnace design allowing space-based processing up to 1,600 degrees Centigrade and above. ETTF was designed to investigate how flaws form in cast and sintered metals. Studying the basic thermodynamics and behavior of pores and metal grains allowed metallurgists to make stronger machine tools on Earth.
Commercial Protein Crystal Growth (CPCG) Experiments:STS-79 included the 31st Shuttle flight of a Protein Crystal Growth payload. The complement of CPCG experiments aboard this mission was comprised of 128 individual samples involving twelve different proteins. The samples were processed at 22 degrees Centigrade using the newly developed Commercial Vapor Diffusion Apparatus (CVDA). The goal of these experiments was to produce large, well-ordered protein crystals in the microgravity environment from very small volumes of protein solutions. These crystals will be used for x-ray diffraction studies to determine the three-dimensional structures of the individual proteins singly, and as they are bonded to other key molecules.
Mechanics of Granular Materials: This experiment seeked to develop a quantitative scientific understanding of the behavior of cohesionless granular materials in dry and saturated states at very low confining pressures and effective stresses. Cohesionless granular materials are unlike other engineering materials since their strength and stiffness properties derive entirely from friction and dilatancy. Dilatency is the change of volume associated with the application of shear stresses. The strength and stiffness of these materials are usually several orders of magnitude lower than cementious composites. Granular material properties depend on confinement. Investigators expect to see higher axial loads for a given axial displacement in microgravity. This data could help scientists to understand the behavior of the Earth's surface during earthquakes and landslides.
During theSTS-79 mission, the crew used an onboardIMAX camera to document activities on Atlantis andMir.
NASA has flownIMAX camera systems on many Shuttle missions. Footage fromSTS-79, as well as the recentSTS-63,STS-71, andSTS-74 missions was incorporated in a large-format feature film aboutNASA's cooperation with Russia. TheIMAX system consisted of a space-qualified 65 mm camera, lenses, rolls of film, lights and other equipment necessary for filming. TheIMAX and supporting equipment are stowed in the middeck of the orbiter. An audio tape recorder with microphones will be used in the crew compartment to record audio sounds and crew comments during camera operations.
ThisIMAX camera remained onMir.
Ham radio operators and students attempted to make radio contacts with the orbiting Shuttle as part of the Shuttle Amateur Radio Experiment,SAREX, duringSTS-79. Amateur radio has been flying aboard Space Shuttles since 1983.
Mission Specialist JeromeApt's amateur radio call sign is N5QWL. JeromeApt has flown on three previous Shuttle missions and has operated amateur radio during each flight. JohnBlaha also served as a Mission Specialist, and his ham radio call sign was KC5TZQ. Astronaut CarlWalz was KC5TIE; he participated inSAREX from Columbia duringSTS-65 in July 1994.
Once Atlantis was ready to undock fromMir, the initial separation was performed by springs that gently pushed the shuttle away from thedocking module. Both theMir and Atlantis were in a mode called "free drift" during the undocking, a mode that has the steering jets of each spacecraft shut off to avoid any inadvertent firings.
Once the docking mechanism's springs had pushed Atlantis away to a distance of about two feet (61 centimeters) fromMir, where the docking devices were clear of one another, WilliamReaddy turned Atlantis' steering jets back on. Immediately, he fired the shuttle's jets in the Low-Z mode to begin slowly moving away fromMir.
Atlantis continued away fromMir to a distance of about 600 feet (182.9 meters), where WilliamReaddy and Pilot TerrenceWilcutt began a flyaround of the station. Atlantis circledMir twice before firing its jets again to depart. During this flyaround the crew performed documentary photography of theMir space station, including the newly arrived "Priroda" science module, using still and video cameras as well as theIMAX large format movie camera.