International Flight No. 191
81st Space Shuttle mission
|10d 04h 55m 21s
|Brent Ward, Jr.
|10d 04h 55m 21s
|Peter Jeffrey Kelsay "Jeff"
|10d 04h 55m 21s
|MS-2, EV-2, FE
|10d 04h 55m 21s
|10d 04h 55m 21s
|132d 04h 00m 20s
|SSME (1 / 2 / 3):
|2041-1 (2.) / 2034 (8.) / 2042-1 (1.)
|BI-082 / RSRM 54
|Left Pod 03 (22.) / Right Pod 04 (18.)
|FWD RCS Pod:
|FRC 4 (18.)
|EMU No. 3010 (PLSS No. 1010) / EMU No. 3009 (PLSS No. 1009)
Launch from Cape Canaveral (KSC) and landing on Cape Canaveral (KSC), Runway 33.
This was the fifth of nine planned missions to Mir and the second one involving an exchange of U.S. astronauts. Astronaut John Blaha, who was on Mir since September 19, 1996, was replaced by astronaut Jerry Linenger. He spent more than four months on Mir and returned to Earth on Space Shuttle Mission STS-84, launched in May 1997. Atlantis again carried the SPACEHAB module in the payload bay of the orbiter. The double module configuration housed experiments to be performed by Atlantis' crew along with logistics equipment to be transferred to Mir.
The current Mir-22 mission began when cosmonauts Valeri Korzun and Aleksandr Kaleri were launched on August 17, 1996, in Soyuz TM-24 and docked with the Mir two days later. John Blaha joined the Mir-22 crew with the September 19, 1996, docking of STS-79. John Blaha completed his stay on Mir and returned with the STS-81 crew. Jerry Linenger will work with the Mir-22 crew until the arrival of Mir-23 cosmonauts Vasili Tsibliyev, Aleksandr Lazutkin and German Research Cosmonaut Reinhold Ewald on board Soyuz TM-25 in early February 1997. After the Mir-22 crew and Reinhold Ewald returned to Earth in the Soyuz TM-24 spaceship, Jerry Linenger will complete his tour with the Mir-23 crew.
Atlantis' rendezvous and docking with the Russian space station Mir actually began with the precisely timed launch of the shuttle on a course for the Mir, and, over the next two days, periodic small engine firings that gradually brought Atlantis to a point eight nautical miles (14.8 km) behind Mir 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 the Mir space station and conducted a Terminal Phase Initiation (TI) burn, beginning the final phase of the rendezvous. Atlantis closed the final eight nautical miles (14.8 km) to Mir during the next orbit. As Atlantis approaches, the shuttle's rendezvous radar system began tracking Mir and providing range and closing rate information to Atlantis. Atlantis' crew also began air-to-air communications with the Mir crew using a VHF radio.
As Atlantis reached close proximity to Mir, 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 the Mir, the shuttle had the opportunity for four small successive engine firings to fine-tune its approach using its onboard navigation information. Identical to prior Mir dockings, Atlantis aimed for a point directly below Mir, along the Earth radius vector (R-Bar), an imaginary line drawn between the Mir center of gravity and the center of Earth. Approaching along the R-Bar, from directly underneath the Mir, allows natural forces to assist in braking Atlantis' approach. During this approach, the crew began using a handheld laser ranging device to supplement distance and closing rate measurements made by other shuttle navigational equipment.
The manual phase of the rendezvous began just as Atlantis reached a point about a half-mile (900 meters) below Mir. Commander Michael Baker flew the shuttle using the aft flight deck controls as Atlantis began moving up toward Mir. Because of the approach from underneath Mir, Michael Baker 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 at Mir. This technique avoids contamination of the space station and its solar arrays by exhaust from the shuttle steering jets.
Using the centerline camera fixed in the center of Atlantis' docking mechanism, Michael Baker centered Atlantis' docking mechanism with the Docking Module mechanism on Mir, 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, Michael Baker 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 with Mir to inform the Mir crew of the Shuttle's status and to keep them informed of 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 Jeffrey Wisoff had to oversee the operation of the Orbiter Docking System from onboard Atlantis.
Docking occurred at 03:54 UTC, January 15, 1997, followed by hatch opening. Jerry Linenger officially traded places at 23:45 UTC with John Blaha who spent 118 days on the station and 128 days total on-orbit. Jerry Linenger was Mission Specialist-4 for launch through docking with Mir. Shortly after docking, Jerry Linenger and John Blaha conducted their handover with Jerry Linenger becoming a member of the Mir-22 crew and John Blaha becoming Mission Specialist-4 through the end of the flight.
Atlantis carried the SPACEHAB double module providing additional middeck locker space for secondary experiments. During the five days of docked operations with Mir, the crews transferred water and supplies from one spacecraft to the other. A spacewalk by Jerry Linenger and one by his Russian cosmonaut crewmates occurred after the departure of Atlantis.
STS-81 was involved in the transfer of 2,710 kilograms (6,000 lb) of logistics to and from the Mir, the largest transfer of items to date. During the docked phase, 635 kilograms (1,400 lb) of water, 516.1 kilograms (1,138 lb) of U.S. science equipment, 1,000.7 kilograms (2,206 lb) of Russian logistics along with 121.7 kilograms (268 lb) of miscellaneous material was transferred to Mir. Returned to Earth aboard Atlantis was 570.0 kilograms (1,257 lb) of U.S. science material, 404.5 kilograms (892 lb) of Russian logistics and 97.3 kilograms (215 lb) of miscellaneous material.
The Mir-22 mission began when the crew launched on August 17, 1996, in Soyuz TM-24 and docked with the Mir two days later. John Blaha joined the Mir-22 crew with the September 19, 1996, docking of STS-79. The return of STS-81 concluded a mission of experiments in the fields of advanced technology, Earth sciences, fundamental biology, human life sciences, microgravity, and space sciences, as well as send up new research experiments in these areas. Data gained from the mission supplied insight for the planning and development of the International Space Station, Earth-based sciences of human and biological processes, and the advancement of commercial technology.
Earth sciences research in ocean biochemistry, land surface hydrology, meteorology, and atmospheric physics and chemistry also were performed. Observation and documentation of transient natural and human-induced changes were accomplished with the use of passive microwave radiometers, a visible region spectrometer, a side-looking radar, and hand-held photography. Earth orbit allowed for documentation of atmospheric conditions, ecological and unpredictable events, and seasonal changes over long time periods.
Fundamental biology research continued developmental investigations that study the effects of the space environment on the biological systems of plants. Prolonged exposure to microgravity provides an ideal opportunity to determine the role gravity has on cell regulation and how this affects development and growth. Investigations under this discipline will also characterize the internal radiation environment of the Mir space station.
Human life sciences research consisted of investigations that focus on the crewmember's adaptation to weightlessness in terms of skeletal muscle and bone changes, psychological interactions, immune system function, and metabolism. In addition, environmental factors such as water quality, air quality, surface assessment for microbes, and crew microbiology were assessed. These ambitious investigations continued the characterization of the integrated human responses to a prolonged presence in space.
Space science research continued with the externally mounted Mir Sample Return Experiment (MSRE) and Particle Impact Experiment (PIE) payloads. These experiments continued to collect interstellar and interplanetary space particles to further our understanding of the origin and evolution of planetary systems and life on Earth.
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 collaborative NASA/Mir Science program, a series of measurements were compiled of the ionizing radiation levels aboard Mir. During the mission, radiation was measured in six separate locations throughout the Mir using a variety of passive radiation detectors. This experiment continued on later missions, where measurements will be used to map the ionizing radiation environment of Mir. These measurements will yield detailed information on spacecraft shielding in the 51.6-degree-orbit of the Mir. Comparisons were made with predictions from space environment and radiation transport models.
Greenhouse-Integrated Plant Experiments: The microgravity environment of the Mir 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 the Mir 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 planned for the Mir-23NASA 4 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, baseline saliva and blood sample were collected. While on Mir, 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.
Diffusion-Controlled Crystallization Apparatus for Microgravity: Protein crystals are used in basic biological research, pharmacology and drug development. Earth's gravity affects the purity and structural integrity of crystals. The low gravity environment in space allows for the growth of larger, purer crystals of greater structural integrity. Therefore, the analyses of some protein crystals grown in space have revealed more about a protein's molecular structure than crystals grown on Earth. During STS-81, astronauts retrieved protein samples that have been growing on Mir since the STS-79 docking on September 19, 1996 and replaced them with new samples.
In the experiment chamber called the Diffusion-controlled Crystallization Apparatus for Microgravity (DCAM), crew members removed the "growing" samples and replaced them with 162 new samples. The DCAM was designed to grow protein crystals in a microgravity environment. It used the liquid/liquid and dialysis methods in which a precipitant solution diffused into a bulk solution. In the DCAM, a "button" covered by a semi-permeable membrane held a small protein sample but allowed the precipitant solution to pass into the protein solution to initiate the crystallization process. The DCAM was a method to passively control the crystallization process over extended periods of time.
Gaseous Nitrogen Dewar: Frozen protein samples were transported to the Russian Mir space station in a gaseous nitrogen Dewar (GN2 Dewar) on STS-81, and the existing protein crystals on board Mir from the STS-79 mission were returned to Earth for laboratory analysis. The Dewar was a vacuum jacketed container with an absorbent inner liner saturated with liquid nitrogen. The protein samples remained frozen for approximately two weeks, until the liquid nitrogen had completely boiled off. This provided ample time to transport and transfer the Dewar to the Mir station. After the liquid nitrogen is completely discharged, the samples will thaw to ambient temperature and protein crystals will nucleate and start growing over the four-month duration of the mission.
Liquid Metal Diffusion (LMD) using MIM: The LMD experiment measured the diffusion rate of molten indium at approximately 392 F (200 degrees Celsius). Diffusion is the process by which individual atoms or molecules move as a result of random collisions with neighboring atoms and molecules. Diffusion is difficult to study on Earth because gravity masks the effect of the collisions, that is, hot pockets of liquid rise while the more dense, cooler areas sink. Radiation detectors in the LMD hardware measured the diffusive motions of a radioactive tracer in non-radioactive indium. The Microgravity Isolation Mount (MIM) was used to isolate the experiment from vibrations which could disturb the liquid indium during the experiment and induce motions which are not diffusive. The MIM also was used to provide measured vibrations for some samples to determine how easily diffusion can be affected by these forces. A total of five samples were processed. The information obtained from diffusion measurements can be used to determine the rate at which material travels between two bodies of fluids separated by a stagnant layer which the material must diffuse through. This is a common occurrence for some types of crystal growth and alloy processing on Earth.
Optical Properties Monitor (OPM): OPM was the first experiment capable of relaying on-orbit data which measured the effect of the space environment on optical properties, such as those of mirrors used in telescopes, and structural elements, such as the coatings used on space hardware. OPM instruments measured various optical properties of the, overall showing to what extent the samples deteriorate over the course of the experiment. Once aboard Mir, American astronauts and Russian cosmonauts mounted the monitor to the outside of the space station. This marked the first experiment deployed jointly by the U.S. and Russia, setting the stage for how the astronauts and cosmonauts will work together on the International Space Station.
During its scheduled nine months on Mir, the experiment measured the environment's effect on nearly 100 sample materials. The monitor was the first externally powered experiment in space, using a power-data line to receive power from and transmit information to the Mir. The monitor collected and stored measurements to be transferred weekly to a Mir computer, then to scientists on Earth.
The crew also tested on Shuttle the Treadmill Vibration Isolation and Stabilization System (TVIS), designed for use in the Russian Service Module of the International Space Station. Another activity related to International Space Station involved firing the orbiter's small vernier jet thrusters during mated operations to gather engineering data.
Once Atlantis was ready to undock from Mir, the initial separation was performed by springs that gently pushed the shuttle away from the docking module. Both the Mir 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 have pushed Atlantis away to a distance of about two feet (61 centimeters) from Mir, where the docking devices were clear of one another, Atlantis' steering jets were turned back on and fired in the Low-Z mode to begin slowly moving away from Mir.
Atlantis continued away from Mir to a distance of about 600 feet (182.9 meters), where Pilot Brent Jett began a flyaround of the station. Atlantis circled Mir twice before firing its jets again to depart the vicinity of the station.
Last update on March 27, 2020.