STS-73 Day 5 Highlights
Back to STS-73 Flight Day 04 Highlights:
- On Tuesday, October 24, 1995, 8 a.m. CDT, STS-73 MCC Status Report # 09
- Columbia's crew worked through the night in the shuttle's cargo bay
research lab with no significant spacecraft problems encountered.
Flight controllers in Mission Control have virtually no issues of
concern with Columbia's systems, which continue to operate nearly
perfectly. The Red team began a 12-hour shift at 6:38 a.m. CDT,
relieving the Blue team crew members who had worked through the night.
- During the night, there was a short loss of communications with
Columbia. The shuttle was out of touch with the ground for a few
minutes longer than planned following a normal loss of communication
that occurs each orbit as it moves out of range of the NASA
communications satellites. The extended loss of signal was due to a
ground problem with the communications network and did not interrupt
any lab or spacecraft operations nor pose any problem for the
crew. The ground problem was quickly corrected and Columbia's
communication systems were confirmed to be in excellent condition with
no functional problems.
- On Tuesday, October 24, 1995 at 6 a.m. CDT, STS-73 Payload Status Report # 06
reports: (3/21:07 MET)
- Experiments aboard the Shuttle Columbia continue to operate
extremely well as the second United States Microgravity Laboratory
enters its fifth day in space. Fluid physics studies, unhampered by
the distortions caused by gravity, again took center stage.
- As he had for the previous two nights, Payload Specialist Fred
Leslie devoted most of his shift to the Lewis Research Center's
Surface Tension Driven Convection Experiment. The study seeks a
precise understanding of flows created by temperature differences
across a liquid's surface, called thermocapillary flows. In
particular, the USML-2 experiment should determine the conditions
under which thermocapillary flows begin to oscillate, or become
irregular. While thermocapillary flows are almost impossible to study
on the ground because of the overpowering influence of gravity, they
can affect processing of molten materials on Earth such as formation
of semiconductor crystals or precision welding.
- Leslie used a larger experiment chamber than he had on previous
surface tension experiment runs -- 3/4-inch (2 cm) diameter as opposed
to 1/2-inch (1.2 cm) -- and heated the silicone oil surface with a
laser. The surface was flat for the first three runs and curved for
the fourth. Principal Investigator Dr. Simon Ostrach believes that
the onset of oscillations is affected by a number of factors,
including heat source, temperature distribution on the fluid surface,
surface shape and container size. USML-2 experiments are using
multiple combinations of conditions to build a through understanding
of oscillatory thermocapillary flow in microgravity.
- The Geophysical Fluid Flow Cell Experiment team controlled their
investigation remotely from Marshall's Spacelab control center, with
input from colleagues at the University of Colorado in Boulder.
Payload Specialist Leslie, a co- investigator for the experiment,
calls it "a planet in a test tube." Silicone oil between two rotating
hemispheres can be manipulated to simulate fluid flows in the
atmospheres of giant gas planets, the sun or the Earth. Last night's
experiment simulated atmospheric dynamics of the sun .
- When ground-based experiments use spheres as planetary models,
gravity exerts force in a single direction. Therefore, a uniform
gravitational force cannot be exerted on all the sphere's surfaces.
In space, simulated gravities can be varied as necessary. This
experiment should give theorists insights for interpreting and
predicting problems in complex fluid systems, including Earth's
atmosphere, oceans, core and mantle.
- Mission Specialist Cady Coleman is conducting the mission's first
run of the Glovebox Interface Configuration Experiment for Principal
Investigator Dr. Paul Concus of the Lawrence Berkeley Laboratory in
California. The study examines how movements of fluids in
microgravity, such as fuel in spacecraft tanks, are influenced by the
shapes of their containers. On Earth, gravity causes fuel and other
liquids to drain from containers in predictable ways. When planning
space-based operations, it is important to be able to predict the
locations and configurations that fluids will assume in containers
under low-gravity conditions. Thus far, mathematical models exist for
only a few container shapes. Coleman used a wedge-shaped vessel for
this run, adjusting the wedge angle to see how different angles affect
- Earlier, Coleman spent several hours following up on Glovebox
Protein Crystal Growth experiments she began on previous shifts.
Experiment team members at the Center for Macromolecular
Crystallography in Birmingham, Ala., sent Coleman instructions for
modifying conditions as she activated a new batch of proteins. She
will compare growth progress in the various samples to determine which
conditions work best for specific types of proteins.
- Mission Specialist Mike Lopez-Alegria and Coleman also monitored
other protein crystal experiments onboard. This mission carries a
record number of protein samples and protein crystal growth
facilities. The European Space Agency's Advanced Protein
Crystallization Facility enables videotaping of three different
methods of crystal growth. Marshall Space Flight Center has two
protein crystal growth experiments on USML-2, which use a total of
four facilities. In addition to their Glovebox experiment, the Center
for Macromolecular Crystallography is growing more crystals in the
often-used Vapor Diffusion Apparatus as well as by a newer batch
- Proteins are molecules which serve biological functions.
Understanding the structure of these molecules gives scientists an
idea what other molecules would interact with the protein and change
the way it functions, for instance to help cure or treat an illness.
Space-based protein crystal growth experiments have consistently
produced high-quality crystals for structural analysis, as well as
providing better understanding of the dynamics of protein crystal
- Red team members will devote the majority of their upcoming shift to
Drop Physics Module, Surface Tension Driven Convection Experiment and
Glovebox Protein Crystal Growth operations.
- On Tuesday, October 24, 1995, 6 p.m. CDT, STS-73 Payload Status Report # 07
reports: (4/09:07 MET)
- "This mission is a beautiful example of interactive science due to
the collaborative efforts between the principal investigators, the
cadre and the crew," observed Mission Scientist Marcus Vlasse
referring to the second United States Microgravity Laboratory (USML-2)
mission. USML-2 scientific investigations continue to operate
smoothly and on schedule.
- Downlink video from the Shuttle on Hi-Pac TV this morning displayed
a circular image that appeared to contain a swirling nocturnal
snowstorm. This was actually an experiment run of the Surface Tension
Driven Convection Experiment which studies thermocapillary flows using
aluminum oxide particles suspended in silicone oil illuminated by a
laser light. By relaying commands to Payload Commander Kathy Thornton
to adjust the temperature parameters on the surface of the liquid,
Project Scientist Alex Pline and his science team are able to study
the transition from steady fluid flows to more oscillating, or
unstable flows, that result when heat is applied to a liquid's
- Thermocapillary flows are present on Earth in many industrial and
materials processing methods, but are difficult to study due to the
presence of gravity-driven fluid flows. By conducting this experiment
in microgravity, scientists can isolate the thermocapillary flows,
gaining insight on how and why they occur.
- The Astroculture plant growth facility continues to operate
smoothly, providing the proper water, humidity and light to the small
potato tubers growing within the apparatus. Co- investigator Dr. Ted
Tibbitts commented on the progress of the 10 small potatoes. "They
look very happy and well, staying very turgid, which means they have
not wilted, so the environment is good for them," he said. Downlink
video shows only green leaves, since the tubers are buried in the
soil. That's the exciting part, Tibbitts said, but something their
team won't see until the end of the mission.
- The potatoes will be studied after the mission to determine the
effects microgravity has on starch accumulation in plants. Scientists
believe plants will play an important role in long-duration space
flights, such as missions on the International Space Station,
providing food and water to crews, replenishing oxygen and also
helping remove excess carbon dioxide from the air. Investigators also
believe plants could provide a psychological lift to astronauts in an
otherwise sterile environment.
- "I think it's beautiful," exclaimed Payload Specialist Al Sacco
describing the 1 inch (8 cubic centimeter) drop of water he
successfully deployed and released from the Drop Physics Module
apparatus this morning. A crew member manipulates the liquid drops
using sound waves in order to study their behavior under the influence
of external forces. This type of research will help investigators
understand science and technology in which liquid drops have a role,
from rain formation and weather patterns to chemical processing.
- Later this week, an experiment known as Science and Technology of
Surface-Controlled Phenomena will be conducted with a surfactant added
to the water drop. Surfactants, such as soap, reduce the holding
power of a liquid surface. These chemicals play an important role in
industrial processes, among them the production of cosmetics, the
dissolution of proteins in synthetic drug production and the
enhancement of oil recovery. Data from these observations should give
a better understanding of the molecular forces acting in the surface
layer of simple water drops and should provide a better basis for
- Near the end of the red shift, Pilot Ken Rominger used a camcorder
to film a couple of unattended experiment operations starting with the
Commercial Generic Bioprocessing Apparatus. This multi-user facility
allows a variety of sophisticated bioprocessing experiments to be
performed in one piece of hardware. Major areas of focus on USML-2
include biomedical testing and drug development, ecological systems
development and biomaterials products and processes.
- Next Rominger focused his camera on the Crystal Growth by
Liquid-Liquid Diffusion apparatus sponsored by the Marshall Space
Flight Center in Huntsville, Ala. The experiment consists of four
transparent hand-held diffusion test cells, attached to the outside of
a Shuttle middeck locker so they are easily seen. In this unique
crystal growth facility, proteins and precipitants diffuse into one
another by random action of molecules instead of being mixed.
- Sacco spent about 4 hours this afternoon in the Glovebox facility
activating protein crystal growth samples. Later the samples were
transferred to a specialized incubator maintained at a prescribed
temperature. Proteins play important roles in daily life, from
providing nourishment to fighting disease. Because a protein's
structure determines its function, researchers seek to grow large,
well-ordered crystals for post-mission structural analysis.
- On Tuesday, October 24, 1995, 5 p.m. CDT, STS-73 MCC Status Report # 10
- The Red Team members will hand over science operations to their
colleagues on the Blue Team at 6:38 p.m. CDT today, then resume work in the
Spacelab at 6:38 a.m. CDT Wednesday.
- On Wednesday's schedule for televised events is an NBC News Channel
interview with Mission Specialist Michael Lopez-Alegria at 5:43
a.m. CDT and a special video downlink at 7:23 a.m. CDT in anticipation
of Game Five of the 1995 World Series. The crew will downlink video of
STS-73 Commander Ken Bowersox throwing out the ceremonial first
pitch. The video will be played on the Jacobs Field TV screen in
Cleveland before Thursday's game.
Go to STS-73 Flight Day 6 Highlights: