Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/STATION/STFSEP90.NWS

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September 1990 Edition of Station Break

Crew's Good Health Critical to Station Success

        Until we visited space, the human body had never been free
of gravity.  In space, there is neither up nor down -- no gravity
pressing against the muscles, no gravity to help move fluids to
the lower body.
        Since the crew's expertise lies at the heart of Space
Station Freedom's mission, crew well-being is a priority,
especially for long-term missions.  The health systems being
designed for Freedom today will help astronauts stay healthy. The
Biological Monitoring and Countermeasures (BMAC) facility and the
Crew Health Care System (CHeCS) will help Earth-bound doctors,
investigators and scientists set up a biomedical human physiology
knowledge base.
        "BMAC will monitor physical deconditioning and provide
countermeasures," said  Dr. Don Stewart, Manager of the Aerospace
Medicine Program Office.  By providing immediate information on
the status of each astronaut's health, exercise can be prescribed
that may mitigate any problems.  "The key role of BMAC is
establishing new norms for space," Stewart said.    The
accumulated data also will help determine which changes are
temporary, and which will require countermeasures to be reversed.

        Life science experiments conducted on Skylab and Shuttle
missions reveal a set of physiological changes that affect
virtually all body systems.  Changes  often begin during the
initial hours of space flight, suggesting that the body responds
rapidly to variations in environment.
        "One of the things that happens to people in a microgravity
environment is that they go through a process of deconditioning
that varies from system to system," said  Stewart.  This
deconditioning makes the task of ensuring crew health, safety,
and performance particularly challenging for NASA life scientists
working on Space Station Freedom in light of future long-duration
missions.  Extended-duration missions are necessary to  carry out
long-term experiments and to rotate crew with a minimum number of
Shuttle flights.
        Since crew members will gradually build up to longer and
longer missions,  the Office of Space Science & Applications'
Life Sciences Division must medically qualify crew-members for
tours of duty  on Space Station Freedom.  By evaluating  and
minimizing crew health  risks, NASA  hopes to prevent  in-flight
medical emergencies.  This is accomplished by means of
countermeas-ures, such as exercise, to slow space flight
deconditioning.
        A space-related problem  scientists face is that fluid, in
space, no longer pools in the lower extremities  but accumulates
in the upper body.  This fluid increases pressure in blood
vessels, and the kidneys and glands take actions to remove what
appears to be excess fluid, causing dehydration.  On Earth, blood
tends to pool in the feet and legs, while muscle contractions
help push blood back to the heart. In space, muscles  and bones
no longer  strain against gravity when they contract, andbones do
not have to retain as much strength to support a weightless body.
As a result, the muscles lose protein and the bones lose calcium.
Metabolic processes such as hormone production and immune system
functions may be altered.  Learning how to avoid and counteract
such problems is essential to improving quality work time.
        NASA life scientists have had to  largely rely on postflight
data and anecdotal evidence to identify cardiovascular
deconditioning, as seen in the in-flight loss of exercise
capacity, and  electrocardiogram  (EKG)  changes. The Soviets,
however, have had more experience documenting the effectiveness
of cardiac countermeasures because they perform "real-time"
monitoring of their cosmonauts aboard the Mir space  station.
This allows the exercise prescription to be modified as needed to
keep crew members healthy.
        Another possible consequence of cardiovascular
deconditioning is arrhythmias, an irregular heart beat.  This has
been observed in both the U.S. and Soviet space programs and
resulted in the return to Earth of one of the cosmonauts midway
through a long-duration mission.  The clinical significance of
the heart rhythm disturbances is not yet clear and will require
further evaluation.
        Musculoskeletal deconditioning in space,  or a substantial
loss of muscle strength and mass, has been well documented.  On
Skylab, results showed up to a 20-25% loss in leg strength
despite countermeasures.  On Mir in 1987,  losses of 25-40% were
evident.  There is also loss of total body calcium of .3-.4%
monthly, with heel bone calcium loss of about 5% per month.  This
bone loss appears to be largely reversible but could possibly
limit repeated long-duration flights.
        Other concerns involve the function of the immune system.
Previous studies have indicated suppression of the immune
function, which may cause increased susceptibility to infections.

        In order to address these concerns, OSSA's Life Sciences
Division developed CheCS and BMAC to work side by side to provide
clinical and preventative care, and to conduct investigations
into the effects of microgravity on human physiology.   CHeCS is
a medical system designed to maintain the health of the crew and
provide treatment for inflight emergencies.  BMAC will be
equipped to monitor the health of the astronauts and will aid in
designing countermeasures.
        The major focus of life science research in coming years
will be to determine the physiological effects of long-duration
missions.  Compiling a comprehensive biomedical data base is
necessary to pursue this research, but data are limited because
U.S. long-duration flight
experience is limited (the longest U.S. space flight to date is
the 84-day Skylab mission in 1973-1974).
        Two cosmonauts have spent a full year in orbit on the Mir
space station, but medical data on them are difficult to obtain,
and differences in methods and emphasis  make the available data
difficult to interpret.
        CHeCS will consist of a health maintenance facility, the
environmental control facility , and exercise equipment.  These
facilities will provide clinical care, exercise, and
environmental monitoring.  It will be located in the living
quarters.
        The health maintenance facility, a mini-emergency room, will
be equipped for routine, diagnostic and emergency care.  It also
will be linked with a data base containing medical texts as well
as the health history of each member.   The  computer link also
will allow crew- members to communicate with doctors on Earth for
medical consultation and transmission of data and images.



 Subsystem Review Nears End, No Major Changes Foreseen

        Space Station Freedom managers are winding up for the
December integrated system preliminary design review (PDR), with
the last major subsystem review of the laboratory module set to
end this month.
        The bulk of Freedom's subsystem PDRs is complete, and
station managers foresee no major design changes, said Dr. Earle
Huckins, director of Space Station Engineering at NASA
Headquarters.
        The subsystem PDRs are leading up to an overall integrated
review of the program's requirements, documentation and
preliminary design.  The preliminary design is in the range of 10
to 20 per cent complete at this point in the program.
        Space Station Freedom Director Richard Kohrs said, the
subsystem PDRs are on track, and the station is one year closer
to its first element launch in 1995.
        Scheduled to culminate in December, the overall PDR is a
technical review of the basic design and is conducted prior to,
or very early in, the detailed design phase.  Checkpoints such as
these are placed in the hardware development and mission phases
of the Freedom program to ensure the integrity and success of the
program, Kohrs said.
        The only major issues the program is expectedly grappling
with are resources, which Kohrs said the program understands and
can control.  Since designers began scrubbing theweight and power
requirements in June, the numbers have dropped substantially, but
some work still remains.
        Freedom designers are continuing to hammer down the
resources requirements.
        As of Aug. 15, station managers were nearing the overall
ideal weight goal for station of 512,000 pounds by reducing the
requirements from 655,000 pounds to 547,452 pounds.  Each work
package has continued to drop its weight requirements at each of
the weekly weigh-ins with top station managers.
        Goddard Space Flight Center remains below its weight
allocation.
        Power requirements also have continued to curve down toward
the energy-saving power goal of
45 kW.  Designers were able to scrub those numbers down to
48.63 kW from a high of 59 kW.  Managers are confident the
resource goals will be met.



Robot Shakes Hands with Station Hardware

        In a state-of-the-art robotics laboratory at Goddard Space
Flight Center in Maryland, Space Station Freedom engineers are
testing prototype Electric Power System (EPS) hardware for
telerobot friendliness.
        Working with Goddard robotics engineers, EPS designers from
Lewis Research Center in Ohio shipped a prototype box-type
outdoor unit to the robotics facility for test setup in July.
Designers from both centers want to find out if the orbital
replacement unit's (ORU) design is robot friendly for
maintenance, replacement and repair, and change outs, said Jeff
Rusick, Space Station Freedom project manager at Lewis.
        "We'll have to analyze every-thing when the tests are
completed, but we think we have a solid, basic design,"  Rusick
said.  These tests are increasingly important because station
managers want to rely as much as feasible on robot technology for
Freedom's outside maintenance.
        "This is also good because we're working with the other
centers to coordinate and streamline our projects," Rusick said.
        The term telerobot refers to a hybrid capability for the
robot to operate either under direct control of a human operator
(teleoperation) or to carry out tasks autonomously using computer
commands but allowing human intervention.
        About six operators, including two astronauts, will be
trained to operate the Goddard telerobot and perform the
compatibility test.  Each operator must grapple the box-type ORU,
detach it from the worksite, place it in a stowage area, remove
it from the stowage area and then replace it at its original
worksite.  The box-type ORU could hold any number of objects,
although it was specifically designed for EPS electronics.
        This test will help designers evaluate robot alignment
techniques, robotics compatibility, change out times and
clearances for the robot around the ORU.
        For the test, "We have simulated an enclosed flight-like
environment, with a limited amount of [tele-vision] displays.
Although the telerobotic operators aboard the space station may
have some window view [of the worksites], for the purpose of this
test, we have taken the window view away from the operator," said
Tim Sauerwein, Goddard robotics test conductor.
        The luxury of a window view was taken away from the operator
so the designers can test the camera views, the number of cameras
on the telerobot, the task time completion, the number of task
errors and operator fatigue, Sauerwein said.
        Because the work is tedious and time-consuming, overall
fatigue, especially in the hand and arm, can set in.  Completing
telerobot tasks is complicated because an operator's arm and hand
is strapped to a sophisticated and sensitive arm-length
controller, which the operator uses to manipulate the robot.  The
operator actually sees the worksite through the numerous cameras
mounted to the telerobot, so the camera's clarity is paramount.
Since the operator works in tandem with the robot, any moves he
makes, the robot duplicates at the worksite.  This means the
operator's moves must be well thought out and concise.
        "It's always going to be more difficult for the operator if
he can't actually see with his own eyes what he's working on.
It's going to take longer to analyze the situation and then to do
the actual repair or replacement tasks," Rusick said.  "That's
why it's imperative that the fixtures the robot will be working
on are robot and operator friendly; that's why we designed this
ORU box with simple, easy-to-grasp handles and a robotically
compatible radiant interface," Rusick said.
        Besides searching for robot compatibility, the test's
purpose is also to develop and look at integrating new and
different technology that does not exist in off-the-shelf
merchandise today, said Sauerwein.  "An example of this is 3-D
vision systems for robotics and space-related applications," he
said.
        The station telerobotic test simulator, unique to Goddard,
has two 6-degrees of freedom force reflecting  the arms, and a
6-degree of freedom gantry arm.  The test crew also has created a
robot control room in a Space Shuttle aft deck mockup.  Telerobot
test operators are using three screens inside the mockup to watch
their maneuvers and to monitor how much force the robot has in
relation to their own movements.
        One of Freedom's actual telerobot, known as the Flight
Telerobotic Servicer (FTS), will have two highly dexterous
manipulators, or working arms, and one stabilizer arm, which will
be used as the robot's anchor at each station worksite.  The
Canadian Space Agency also is providing a telerobot.
        Changeable end effectors at the end of 5-foot manipulator
arms act as hands, which will grasp tools used in assembly and
maintenance tasks.  The arms are attached to a compact body that
contains the power, data management and processing, and
communications systems.




KSC Requests Bids to Build Space Station Processing Facility

        Kennedy Space Center (KSC) officials have reached a major
milestone in preparations for Space Station Freedom work at KSC
with the release of a bid package for construction of the new
Space Station Processing Facility (SSPF).
        The solicitation package details  the requirements a bidder
must meet in the construction of the new facility.  The SSPF will
be built in a "phased construction" plan extending over three
years.
        As part of its annual construction of facilities request,
NASA will ask for a total of $88 million for the facility.  The
SSPF, which will be located in KSC's Industrial Area, has been
designed especially for the processing of the Space Station
Freedom manned base hardware components.
        To accommodate items from unpressurized hardware to
pressurized modules, the SSPF will include both a high and
"intermediate" bay, and various laboratories.  In addition to
Space Station Freedom manned base hardware components, the
facility also will process scientific payloads from around the
world.  "The completion of design and the issuance of the
invitation for bids mark a big step forward in KSC space station
work," said Dick Lyon, manager, KSC Space Station Project Office.

        "A lot of hard work has gone into moving toward this step,
and we are looking forward to seeing the actual construction get
underway," he said.
        A pre-bid conference for prospective bidders is scheduled
for 10 a.m. Sept. 6, in the KSC Training Auditorium.  A tour of
the SSPF location will be included.  Companies interested in
obtaining the bid package or attending the conference should
write to NASA, SI-PRO-31, KSC, Fla., 32899.



KSC Gets Taste of Its Own Technology Advancements

        This summer, Kennedy Space Center (KSC) will get a taste of
its own progress when spin-off technology is used to upgrade the
Space Station Logistics and Resupply section of the Payload
Support Building.
        Under a contract awarded to Precision Mechanical, Inc., a
Cocoa, Fla., small business firm, heat pipe technology will be
used in the addition of a new air-conditioning system that will
control the temperature and humidity in the Payload Support
Building.  KSC is the first NASA center to make use of this
energy-saving technology.
        Heat pipes were initially used as an efficient cooling
method for satellites in space.  Later, through the efforts of
the NASA Technology Utilization office, heat pipes were adapted
to assist in air-conditioning and dehumidification of buildings
on Earth.
        Heat pipes eliminate the reheat cycle used in conventional
air conditioners for humidity control and add a precooling cycle
to the main cooling pool.
        Substantial amounts of energy are required to run
inefficient con-ventional air conditioners that must 'over-cool'
the air in order to lower humidity to acceptable levels.  Heat
pipes, however, cool the air before it enters the air conditioner
and then decrease the relative humidity of the cooled air prior
to is entering the room.
        Heat pipes have coolants inside sealed tubes.  These tubes
are placed on either side of the air conditioner -- in front of
the warm air intake and after the cooled air out-flow.  The
liquid inside the heat pipe evaporators absorbs heat from the
incoming warmer air and passes the vapor into the condenser
section of the pipes.  The vapor then recondenses inside the heat
pipe and transfers the heat to the cold air supply coming out of
the air conditioner, thereby lowering the relative humidity of
the air out-flow.
        Because the relative humidity of the passing air is lower,
rooms feel cooler even at the higher air temperatures.
Thermostats can be adjusted and the air conditioners aren't
required to operate as often.
        Outside applications for heat-pipe dehumidification began
with the work of Khanh Dinh of Alachua, Fla.  The Dinh Company
was founded in 1983 to capitalize on heat pipe transfer
technology.
        Working under a contract with NASA, Dinh Company developed a
line of heat pipe dehumidification systems that significantly
increased the moisture removal capacity of conventional
air-conditioning systems.  Such a system will be used in the
Payload Support Building.  Dinh has also introduced a line of
stand-alone heat pipe dehumidifiers for libraries and offices
that offer double the efficiency of conventional
dehumidification.  This has resulted in energy savings to users
of 15 to 20 per cent.
        Technology for the use of heat pipes was recently inducted
into the U.S. Space Foundation's Space Technology Hall of Fame at
Colorado Springs, Colo., during the Sixth National Space
Symposium.
        Current applications of heat pipe technology include uses
on the Alaskan pipeline.



Quick-Reaction Science with Small Attached Payloads

        When many people think of NASA's space science programs,
they think of major projects such as Spacelab or the Voyager
mission through the solar system.  But numerous projects that the
Office of Space Science  and Applications (OSSA) sponsors are
small in size and budget in order to provide all areas of science
a chance to perform space research.  In fact, OSSA has included
in its strategic planning themes a provision for increased
opportunity with small missions.
        For Earth-based missions, these small projects are generally
carried out in the form of balloon and sounding rocket programs.
On the Shuttle, "Get-Away-Special"canisters in the payload bay
and experiment lockers in the middeck area are used for small
investigations.
        For the space station, this concept will take the form of
Small and Rapid Response (SRR) payloads.  While the SRR program
will provide opportunities for both the pressurized and external
facilities on the space station, this article will only address
the station's small attached payloads.
        An attached payload is one that is fixed to the outside of
the space station, on the trusses, for Earth-, solar-, or
celestial-viewing.  The small attached payload program is
designed to allow a number of science missions to be carried out
relatively quickly and inexpensively.
        Because of the simple, straightforward character of the
small attached payloads, they have a streamlined life cycle and
are often referred to as "rapid-response" payloads.
        The task force on Scientific Use of Space Station in 1985
reported, "The space station will provide an ideal logistics base
for accommodating small attached payloads."  Such smaller
programs offer frequent opportunities for experimental
investigators filling a vital role in student training,
instrument development, and innovative science.
        The essential characteristics of these opportunities are
their flexibility and independence, leading to a quick return of
valuable data in the shortest possible time following the
appearance of the concept.
        The processing time for these payloads is shortened, because
most of the dimensions, weights, power requirements, and data
needs will be standardized.  Standardizations will produce
interchangeable parts and reduce individual payload
documentation.
        The accelerated process and reduced cost of the program have
two intended benefits.  First--and very important--the program
can be used to help educate and train future scientists and
engineers.
        The short cycle time of the two to four years from
development through data analysis will provide may hands-on
opportunities for involving young scientists and graduate
students in space science.  The reduced management scope
associated with the shorter cycle times will be more compatible
with universities and small research groups proposing modest
payloads.
        Second, the program is intended to encourage innovative
ideas for focused scientific objectives, to build experience, and
to qualify technologies.  A rapid-response capability will allow
the scientific community to react more quickly to new scientific
discoveries in space or the occurrence of natural events, such as
the explosion of a supernova or the eruption of a volcano.
        OSSA has planned to install five small attached payloads on
Freedom by the time it is permanently manned, and 20 small
attached payloads by the Assembly Complete.  The plan for the
five small attached payloads is derived from the baseline OSSA
Payload Traffic Model, which includes the Laser Communications
Transceiver flight project (see the August 1990 issue of Station
Break for more information on the LCT) and four NEWPIMS (Neutral
Environment With Plasma Interaction Monitoring System) packages.
        The requirements for 20 small attached payloads by Assembly
Complete is driven by (1) an anticipated 7-8 small attached
payloads to be developed per year by the OSSA divisions (Space
Physics, Astrophysics, Earth Sciences, Solar System Exploration,
Communications and Information Systems); and (2) interest
expressed by other NASA offices, such as the Office of
Aeronautics Exploration and Technology and the Office of
Commercial Programs, as well as by other scientific
organizations, such as the Canadian Space Agency and the European
Space Agency.
        The small attached payload program will ensure that a much
greater portion of the science community is involved in the use
of the space station.  In so doing, it will help ensure that the
United States remains a leader in space science.


Timing Is Everything in Space Experiments

        The space station will enable scientists to gain new
knowledge of our own human function and our capacity to live and
work in space.  Many life science experiments planned for the
space station are designed to investigate fundamental questions
about gravity's role in the formation, evolution, maintenance,
and aging processes of life on Earth.
        However, by their nature, many of these experiments are
extremely sensitive.  Experiment results can become
"contaminated" if samples and specimens are not properly
controlled.  Proper control of these samples and specimens
requires quick access to the Shuttle, both before it takes off
for the space station (late access) and when it returns (early
access).  Space Station  Freedom program managers are currently
assessing ways to accommodate the late/early access requirements.

        Late access to certain experiments just before the Shuttle
embarks for the space station is required because changes in the
normal daily routines of laboratory animals can cause significant
stress in the animals.  The longer and more intense  the
disruptions, the longer it will take the animals to return to
pre-stress levels.  The National Institutes of Health has
established national guidelines on  animal handling and care, to
which NASA is required to comply.
        Also, keeping cells and tissues alive and suitable for
experimentation requires careful monitoring by trained scientists
at the launch site until the last possible hour before launch to
prevent damage.  Even when frozen or refrigerated, samples can
decay, and even a one per cent deterioration can destroy an
experiment.
        Early access to the Shuttle carrying space station
experiment samples is necessary because physiological changes can
occur in specimens within minutes of return to Earth's
gravity.  It is essential to retrieve specimens  before the
experiment results have been altered by the return to gravity.
Early access enables the conditions of specimens to be
esta-blished as early as possible, thereby minimizing time- or
gravity-induced changes.
        Early access is also needed by microgravity science
experiments, since many crystals formed on orbit are so delicate
that it is difficult to preserve them in Earth's gravity, and
even a small degradation in the sample can disturb the results of
the experiment.
        A potential alternative to early access may be to analyze
the samples directly on orbit.  Some life science experiments
produce samples that cannot survive long after productions and/or
cannot survive the long wait for a Shuttle trip back to Earth.
For these situations, scientists need the capability to analyze
samples immediately after they are taken -- what scientists call
"on-orbit characterization."  In some cases, experiments may
require analysis of a sample before the ex-periment can continue.
Without on-orbit characterization or the rapid return of a sample
to Earth, a two-week study could turn into a two-year study
because of the need to wait for Shuttle revisits before sample
analysis can take place.
        Long exposure to an essentially zero-gravity environment is
a phenomenon exclusive to the space station that cannot be copied
on Earth  or on the Shuttle.  Space Station Freedom will offer
periods of time in orbit extending into weeks and months rather
than hours or days, allowing scientists to conduct in-depth
biological  and microgravity science research in space.  The
space station planners and the users will continue to work
closely  together to ensure that the space station is designed to
be as efficient and as useful as possible, to get the most
productive return on the nation's research investment.