Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/station/stfjan90.nws

Text File | 1992-09-09 | 19KB | 363 lines

"6_10_8_5.TXT" (18945 bytes) was created on 04-08-90
STATION BREAK, VOL 2, NO 1, JANUARY 1990

NASA Officials  Make Some Changes to Space Station Freedom to Reduce Risk

To meet a budget cut of nearly $300 million for fiscal year 1990, and to
reduce technical, schedule and cost risk in the development of Space
Station Freedom, NASA officials have completed an extensive review and
rephasing of the program resulting in some changes to the baseline space
station configuration.  First element launch has been maintained in the
first quarter of 1995, however subsequent milestones have been stretched
out.

Although rephasing has resulted in some changes to, and deferrals of some
Freedom subsystems and delayed its completion by about 18 month, Freedom's
capabilities will remain intact, said Dr. William B. Lenoir, associate
administrator for Space Flight.  "With the rephasing of the program,
assembly complete will come later," Lenoir said.  " But we will pay closer
attention to the interim capabilities, and use them.  Even when we're part
way there," he said, "it's a great space station."

The Congress passed a bill in October to fund the space station program at
$1.8 billion, $250 million less than the Bush administration's $2.05
billion request.  Further reductions to help fund the battle against drugs
and enable the Congress to meet Gramm-Rudman-Hollings budget deficit
targets were taken from NASA, other government agencies.  Freedom's share
of that reduction was $48 million from the amount agreed upon by Congress,
thus reducing station's operating funds for fiscal year 1990 to $1.749
billion.

NASA began an initial assessment of the Freedom program in July under
threat of a significant reduction in the fiscal year 1990 budget, and to
review the status of the program as it prepared to enter the preliminary
design phase of the project.  A team of 17 NASA managers met at NASA's
Langley Research Center for three weeks and developed options.  They were
directed to
hold early program milestones, including the First Element Launch, support
user requirement and the ability of Freedom to grow to meet future needs,
and maintain agreements with the International partners.

The Langley team's proposals were then handed to workers at the NASA
centers and their contractors, the user groups and the international
partners to study their feasibility.  Ultimately, a number of changes to
the configuration were approved.  "Essentially, what we're doing is
stretching out buying hardware" to reduce the yearly budget, said Richard
Kohrs, director, Space Station Freedom.

Major changes in the configuration included:
* Changing from a hybrid AC/DC power system to a solely AC system, and
delaying availability of the full 75 kilowatts of electrical power from
February 1997 until November 1997.  Although the change to an all-DC
system will add weight, Kohrs said, the cost savings will be significant.
* Deferring indefinitely development of new high-pressure spacesuits.
Instead, the existing suits used by astronauts who perform extravehicular
activities from the Space Shuttle will be used.
* Changing the propulsion system from one which burns hydrogen/oxygen to
modular units powered by hydrazine, the same propellant which powers the
maneuvering engines on Space Shuttle orbiters.

Allowing engineers building the unmanned polar-orbiting platform to
develop unique hardware, specifically suited to the platform's key role in
the Earth Observing System mission, instead of relying on hardware
developed by other NASA centers and their contractors.

Kohrs said these changes will save hundreds of millions of dollars over a
three to four year period and will not drive up the runout cost of the
program.  "Operations life-cycle cost will go up some, primarily because
of the hydrazine that periodically will have to be brought up to the
station, but it shouldn't be significant," Kohrs said the proposed changes
would add about one Shuttle flight every two years.  "Delay of some
milestones and capabilities was unavoidable, but the essential station
capabilities are maintained and will be available by assembly complete."

The program has several major studies underway to look at laboratory
support equipment, the availability of ultra-pure water for use in the
laboratory, the need for a pointing system for attached payloads, a system
for transporting living specimens to the station, and the need for a
system to monitor electromagnetic interference, and for an acceleration
mapping system.


NASA Administrator Consolidates
Offices of Space Flight, Space Station

NASA Administrator Richard Truly last month approved the consolidation of
the Offices of Space Flight and Space Station.  The newly formed single
office, headed by Associate Administrator Dr.  William B. Lenoir, will be
called the Office of Space Flight.

"The consolidation provides a structure within which the leadership and
accomplishment of assigned programs and division of responsibilities is
clear and the mechanisms to assure coordination are in place."

Officials plan for the Space Flight organization to include four major
areas:  Space Station Freedom, Space Shuttle, Space Flight Systems, and
Human Resources Institutions.Richard Kohrs continues as the director of
Space Station Freedom  at Headquarters in Washington, D.C.  Robert L.
Crippen is the acting director of the  Space Shuttle Program.

While the combination makes no major changes in the Space Shuttle program,
the most significant changes were made to program management
organizational elements of the Freedom program.  The change has
strengthened the program's organization and program management was
consolidated into NASA Headquarters and Reston, Va.

The program director's office now will include three major functions:
engineering, operations, and policy.  Robert Moorehead, deputy director,
is located in Reston.  The deputy director is supported by Richard A.
Thorson, deputy program manager for integration located at Johnson Space
Center (JSC) in Houston, Texas.  Thorson is JSC's former deputy manager
for the Shuttle program.

Thorson is supported by two field offices, with James M. Sisson as manager
for element integration at the Marshall Space Flight Center in Huntsville,
Ala., and Jesse F. Goree Jr. as manager for systems integration at JSC.
Sisson is the former acting deputy director of the Reston program office.
Goree is the former manager for integration at JSC's Space Station Project
Office.

At Reston, strong staff offices in system engineering and analysis,
management integration, and safety, reliability and quality assurance are
retained.


Sage III: A Payloads on a "Mission to Planet Earth"

In the December issue of Station Break, OSSA highlighted one of the three
payloads for the manned base associated with the "Mission to Planet
Earth."  That payload was CERES, which stands for Clouds and Earth's
Radiant Energy System.  This month SAGE III, the Stratospheric Aerosol and
Gas Experiment, is discussed.

The Mission to Planet Earth is a major international program to
intensively study our own planet with the goal of improving and preserving
the life giving qualities which are not found anywhere else in our solar
system.  NASA's contributions to the attainment of this goal are
significant.  The Earth Observing System (EOS), which is the cornerstone
of the effort, includes six polar platforms, instruments to be flown on
Space Station Freedom, and instruments to be flown on the European and
Japanese space agencies' polar platforms.

The instruments selected for development, which are candidates for flight
on Space Station Freedom, are called 'attached payloads.'    EOS has
proposed nine instruments as attached payloads.  These are divided into
two phases, the Space Station Freedom assembly phase and the operational
phase.  For the first phase, EOS has selected three instruments:  (1)
Clouds and the Earth's Radiant Energy System (CERES), (2)  Stratospheric
Aerosol  and Gas Experiment (SAGE III), and (3)  Lightning Imaging Sensor
(LIS).

The Stratospheric Aerosol and Gas Experiment III is an instrument that was
proposed to be flown on the EOS polar platform, the European Space Agency
(ESA) platform, and the Space Station Freedom.  NASA selected SAGE III for
both the EOS polar platform and an attached payload for Freedom.

SAGE III will provide global profiles, with 1 and 2 kilometer resolution,
of aerosol, ozone, water vapor, nitrous dioxide, cloud top heights, and
air density in the mesosphere, stratosphere, and troposphere.  SAGE III is
totally self-calibrating, capable of determining long-term trends, and a
simple algorithm allows prompt archival and data retrieval.

The data provided by SAGE III provides a tool for investigating the
spatial and temporal variability of the measured species and their roles
in climatological processes, biogeochemical cycles, and the hydrologic
cycles.  The EOS platforms will provide global coverage whereas Freedom
will provide the environment for obtaining diurnal cycle information.

SAGE III is a natural and improved extension of instruments starting with
the Stratospheric Aerosol Measurement (SAM) instrument on the ASTP 1975
mission, SAM II on the NIMBUS-7 (1979-1988), SAGE on the AEM-2
(1979-1981), and SAGE II on ERBS (1984-1988).  Freedom and the EOS
platforms are expected to provide continuous SAGE III measurements from
1998 through 2013.

SAGE III is a 60 kilogram limb-viewing instrument developed by NASA's
Langley Research Center in Hampton, Va.  It uses about 45 watts, has an
average data rate of 10 kilobits per second, and its nine channels cover
the spectrum from 290 nanometers to 1550 nanometers.  Ball Aerospace
Division in Boulder, Colo., will develop SAGE III.  The principle
investigator is Dr. M.P. McCormick and he is supported by an international
science team of 19 members.

For more information on the Mission to Planet Earth and the EOS program as
they relate to Space Station Freedom, contact Alex Tuyahov at NASA
Headquarters, [phone].


Life Sciences Centrifuge Facility Can Create Gravity for Experiments

It is well known that the space environment produces many physiological
and biochemical changes in humans and other living organisms.  In order to
separate the effects of weightlessness from other variables in space
flight, it is essential to provide an Earth gravity (1-G) control
environment through the use of onboard centrifuge.

The Life Sciences Centrifuge Facility will provide the means to produce
artificial gravity and accurately controlled acceleration levels on Space
Station Freedom for research using specimens such as plants and small
animals.  This research will contribute to a more comprehensive
understanding of the physiology of humans in space which will in turn
advance NASA's charge to assure health, safety and well-being of space
crews.

Both internal NASA advisory panels and independent, external groups, have
strongly and repeatedly endorsed the need for an onboard centrifuge
facility.  Without such a facility, it is impossible to conduct the
rigorous and systematic flightresearch that is required, and which is
comparable to the quality of research performed on the ground.

The centrifuge also will provide a test bed for determining the interplay
of artificial gravity with biological specimens within the spacecraft
environment.  The long-duration missions possible only on Freedom will
allow fundamentally new research employing comparisons of human and animal
systems over durations similar to those to be experienced on Lunar and
Mars missions.

These experiments will help NASA determine whether artificial gravity will
be necessary on extended human space missions, and if so, what gravitation
levels are required, and whether therapeutic exposure should be continuous
or intermittent.

The centrifuge facility, consisting of a large centrifuge, habitat holding
units, modular habitats for plants and small animals, a life sciences
glovebox, and a specimen chamber washer/sanitizer, comprises a suite of
hardware ideally co-located.  The illustration below is an artist's
depiction of the centrifuge and habitat holding units, with the life
sciences glovebox located adjacent in the U.S. laboratory module.

These major items, augmented by a variety of laboratory support equipment,
will comprise an on-orbit laboratory for the conduct of non-human life
sciences research, with particular emphasis on gravitational biology.

The modular habitats are especially designed abodes, which, in conjunction
with the habitat holding units  and the centrifuge, will provide full life
support for the plants and small animals to be flown.

Specimens will be bio-isolated from the rest of the pressurized volume but
will be readily observable, both directly and via video.  The centrifuge
will be about 8.2 feet (2.5 meters) in diameter and will hold a number of
habitats containing animals or plants.

Spinning at the rate of about one revolution every two seconds, the
centrifuge will create the effect of normal Earth gravity on the
specimens.  This will provide a control against which to study other
specimens which are exposed to the microgravity environment of space.
By adjusting the rate of rotation the centrifuge will be able to produce
gravity levels between .01 and 2 times that of Earth, thereby allowing
investigators to study the effects of different levels of gravity.

The habitat holding units, each a space station double-rack in size, are
support systems for the habitats in the microgravity environment.  Like
the centrifuge, each holding unit can accommodate a uniform or mixed up
group of habitats, thus supporting concurrent research on multiple
species.  The life sciences glovebox will provide an isolated work area
where specimens   can be handled.

Gloves attached to portholes provide access to the interior of the
glovebox for such tasks as manipulating specimens and transferring
specimens into and out of habitats.

Cleaning or replacement of animal cages will be required at regular
intervals.  This function will be  provided by the specimen chamber washer
/sanitizer.  All water used will be recycled for reuse.

The Centrifuge Facility is being developed at NASA Ames Research Center.
Contracts have been awarded to two contractors to conduct design
definition studies.

For more information on the Life Sciences Centrifuge Facility, contact
Larry Chambers at NASA Headquarters, [phone].



Two Teams Vie for Space Station's Assured Crew Return Vehicle

NASA officials received three proposals for study contracts for the
Assured Crew Return Vehicle (ACRV).  After the initial proposal
evaluation, two proposals remain  in competition.  One proposal team is
led by Lockheed Missile and Space Co. and includes Boeing Aerospace
Electronics and IBM System Integration Division.  The other team is headed
by Rockwell International Space Transportation System Division and
includes McDonnell Douglas System Division, TRW, and Honeywell.

NASA plans to award two parallel contracts providing $1.5 million,
six-month efforts to validate ACRV requirements, to assess feasible
configurations and to examine cost, risks, and schedules.  Start of the
contracts is planned for early April.

The contracts also will include an option valued at $4.5 million, which,
if exercised, would provide for systems definition and preliminary design
of the ACRV system.

The basic contracts plus options, with the potential value of $6 million
each, will support efforts leading to the planned initiation of full-scale
design and development of an ACRV system in 1992.

The ACRV is conceptualized as a vehicle, continuously berthed at Space
Station Freedom, for crew return to Earth in the event of crew illness or
injury or other contingencies which cannot be supported by the Space
Shuttle.

The project will be managed by the Johnson Space Center in Houston, Texas.
For more information, call Kari Fluegel [phone].


Lewis Research Center Completes Tests
on Solar Array Model

"A series of tests designed to evaluate the performance of solar arrays
similar to those that will be used to power Space Station Freedom have
been completed and are considered to be successful," said Lewis Research
Center engineer Marian Felder.

The tests evaluated panel performance at conditions that simulate the
plasma environment of space at low Earth orbit.

The two solar array panels, each containing two hundred 8 by 8 centimeter
silicon solar cells, were developed by Lockheed Corporation and tested in
a vacuum changer at Lewis, Cleveland, Ohio, which produces a 'space-like'
environment.     The panels were subjected to temperatures of 25 to 40
degrees Celsius while being illuminated by a solar simulator which
produces a solar intensity of 0.3 sun.  The arrays were operated at
varying output voltages while being exposed to plasma with ion densities
of 100 to a million ions per cubic centimeter.

Research has shown that there can be electrical interactions between a
space plasma environment and a solar cell power source which can cause
possible short-circuiting and arcing problems.  Therefore, Lewis engineers
devised tests to evaluate the effects of these interactions on the
materials and operational characteristics of the panels.  Felder indicated
that these tests are particularly important since the panels will be
operated at 160 volts, which is the highest voltage proposed to be used
for solar array electric power system on an American spacecraft.

OCP Sponsors Materials Processing Workshop

NASA's Office of Commercial Programs sponsored a two-day Materials
Processing in Space (MPS) Workshop for U.S. industry on November 28th and
29th in Huntsville, Ala.

Twenty speakers, representing the Office of Commercial Programs, Office of
Space Station, Office of Space Science and Applications, Marshall Space
Flight Center, Centers for the Commercial Development of Space, and U.S.
industry, contributed to the workshop program.

The workshop theme was "Pathway to Space Station Freedom" as presentations
focused on near-term flight opportunities, results of recently completed
industrial flight experiments, and plans for space station utilization.
The workshop was designed to provide the maximum opportunity for
discussion among participants as NASA representatives answered questions
regarding Space Station Freedom development status, MPS capabilities,
utilization planning, and experiment integration from company
representatives.    Several events occurring over the past year, including
the resumption of flights under the Space Shuttle program, continuation of
the U.S. sounding rocket program and extensive preparations for
microgravity laboratory flights utilizing Spacelab, have revitalized
commercial interest as well as resulted in greater industrial
participation in space-based research activities.

For more information, contact Dick Ott or Donna Miller, Code CC, at (202)
453-1890.