Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v16_1/v16no127.txt

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Date: Thu,  4 Feb 93 05:31:28
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #127
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu,  4 Feb 93       Volume 16 : Issue 127

Today's Topics:
          An 'agitator' replies (was: Clinton's Promises...)
                 Goals for year 2000. I have a dream.
                      parachutes on Challenger?
                            Riding Comets
                            Shuttle tiles
           Silly distortions of the Japanese space program
             Space Station Freedom Media Handbook - 9/18

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
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    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: 3 Feb 1993 16:58:12 -0500
From: Matthew DeLuca <[e-mail]>
Subject: An 'agitator' replies (was: Clinton's Promises...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:

>If you figure out the total number of person days both spend in space you
>will realize that for every day we spend in space they spend between three
>and four day.

>>I wouldn't say they are doing 'far far' more than we are.

>Anybody who does something three times as much as another IS doing
>more.

There's two ways of looking at it.  Sure, they have more man-hours, but we
have more people.  You never seem to address this point; do you see no value
at all in having a large group of experienced astronauts, as opposed to a
very small group?

>>So what are they doing?  I haven't heard of any real results from their work
>>up there.  I'm sure there are some, but they can't be that earth-shattering.

>It isn't clear to me that you would have heard. I'm sure it isn't earth
>shaterring but it is just getting started. Their station produces
>commercial products. We don't even plan to do that 20 years from now.

As someone else pointed out, a tricke of poor-quality semiconductors.  They
could probably do a lot better buying a Japanese or American lithograph
machine.

>>Believe it or not, there's more to space than the almighty dollar.

>This is why we have a stagnant space program. NASA has suckered you
>into thinking that wasting money is patriotic.

No, not at all.  I am of the opinion that trying to slash costs by selling
out U.S. industry to Soviet technology is a silly idea.  You save money,
sure, but you get less capability *and* there is almost zero groth potential
in the current Russian space program.

>>You're drawing conclusions as to trends in launch costs based on two data
>>points?  Way to stick your foot in your mouth.

>Actually, I am using three data points. The third point is the cost
>of NLS or Shuttle II (take you pick). NLS may be dead but it IS the
>best NASA estimate of the third generation system (it is mere coincidence
>that the third generation system looks a lot like the Russian first
>generation system).

Why do you keep babbling about NASA?  I am of the opinion that NASA is
pretty much out of the manned launch system business after the Shuttle is
gone, except in a technology development role.  Future manned systems are
going to come from a different direction; we're starting to see that now
with the Delta Clipper program.

>>If you notice below, I consider SSTO the next generation.

>But you see, I don't consider SSTO a third generation system. The
>whole basis behind the concept is that launcher designers have been
>going down the completely wrong path for the past 30 years.

No, not really.  The Shuttle was a good idea, although the execution fell
short of the plan for a number of reasons that have been hashed out in this
group in the past.  Going from capsules to a reusable winged vehicle was a
good step forward, and even though it didn't work out as well as planned,
we learned tremendous amounts of technical information from the attempt, and
the next generation of transport is going to benefit from that.

>That makes SSTO a first or maybe second generation system.

More doublespeak.  Capsules one, Shuttle two, SSTO three.  Hopefully.

--
Matthew DeLuca
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp:      ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!matthew
Internet: [e-mail]

------------------------------

Date: Wed, 3 Feb 1993 04:31:40 GMT
From: Nick Szabo <[e-mail]>
Subject: Goals for year 2000. I have a dream.
Newsgroups: sci.space

[e-mail] writes:

>So far what I have seen of NASA and the discussions here, no one has a combined
>plan of what is going on and what our goal is..

To the extent there is a single centrally enforced "dream", our capability
to expand into space is severely damaged.  Any one particular plan is likely
to be the wrong one; certainly the cliched space station/Moon/Mars plans
of yesteryear have been a massively expensive failure.  Fortunately, few
can agree on what "our" goal is or the best way to accomplish it.
There are all sorts of different motivations for doing things in space:

(a) To improve life on earth
(b) To make money, help the economy, etc.
(c) To learn about the origin of the solar system, life, etc.
(d) To colonize the solar system
(e) To watch our heroic astronauts fly
(f) To achieve/maintain/enchance defense capabilities
(g) etc.

I admit to a bias towards space colonization (d), a position which is
sadly in the minority wrt motivation, and even more in the minority wrt
funding clout.  As a result, I look to the other areas to provide the
stepping stones towards space colonization, including the development
of space-based technologies, less expensive launch services, etc.

To expect all these parties to get together and agree on a single
goal is unrealistic, and forcing them to would be very destructive.
Vastly expensive and grandiose goals a "fully manned" SSF, "manned"
Mars missions, etc. are highly destructive, serving the needs of only
party (f) the expense of the others.  A balanced NASA program should
include large numbers of automated planetary missions (for science, party
(c), and prospecting, party (d)), automated life sciences (for party
(d) and the future benefit of party (e)), a very small (<$2 billion/yr
worldwide) astronaut program for party (e), and environmetal monitoring
for party (a).  The largest boost to the space program will continue
to come from the military (f) and commercial (a) sectors, as these
have the largest immediate payback.  Military and commercial efforts
provide the most efficient launcher development, as well as >70%
of the market for same.

Let's hope and pray that we never again have a naive, dictatorial
"vision" imposed on the entire space program by some well-meaning
"dreamer".


--
Nick Szabo                     [e-mail]

------------------------------

Date: Wed, 3 Feb 1993 21:26:16 GMT
From: fred j mccall 575-3539 <[e-mail]>
Subject: parachutes on Challenger?
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Gary Coffman) writes:

>Correct me if I get this wrong netters, but the Shuttle now does
>have an escape mechanism involving parachutes and a pole to get
>clear of the orbiter so as to avoid ditching in a relatively intact
>gliding Shuttle. I seriously doubt this system would have been of
>any use to Challenger's crew since it would take considerable time
>to deploy and use.

As I understand it, it is pretty much acknowledged that the new escape
mechanism doesn't really buy a whole lot in the way of survivability
for the most likely classes of accident.  It is also widely
acknowledged that NO reasonable escape mechanism would have made
Challenger survivable (no way to install ejection seats for some of
the crew, even if willing to take the weight penalty -- and above a
certain speed, ejection isn't survivable, either).

--
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------

[e-mail] - I don't speak for others and they don't speak for me.

------------------------------

Date: Wed, 3 Feb 1993 04:49:21 GMT
From: Nick Szabo <[e-mail]>
Subject: Riding Comets
Newsgroups: sci.space

[e-mail] (Terry Ford) writes:

>What is the possibility of creating a craft that could land on either a near
>earth asteroid, or a comet, and hitch a ride?

This is potentially a good idea, but it wouldn't be useful for saving
energy.  In fact, it would cost some delta-v, because the asteroid
or comet is highly unlikely to be in the optimum orbit one would
normally use for the trip.  The idea could save a very substantial
amount of mass, since the cometary ice can processed and used as
propellant, shielding, and life support instead of hauling all that
up from earth.

For example, many Jupiter-family comets are in orbits that resemble
Earth-Jupiter transfer orbits.  On a trip to Jupiter, astronauts
might use such a comet for radiation shielding, life support supplies,
and propellant.  Unfortuneately the time intervals, or windows, where
a comet gets near Earth's orbit just when the Earth is there, _and_ then
gets near Jupiter's orbit just when Jupiter gets there, are exceedingly
rare.  The prospect is intriguing enough to do a computer search for
such a window, though.

A cheap computer search for asteroids near Earth-Mars transfer windows
might also be worthwhile, especially after we've found all the
mini-asteroids that are likely to be in that region.

In the long run, we'll be able to move ice around so cheaply that
we can put it in the correct transfer orbit instead of waiting for
a natural orbital window.


--
Nick Szabo                     [e-mail]

------------------------------

Date: 3 Feb 93 22:01:41 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Shuttle tiles
Newsgroups: sci.space

In <[e-mail]> [e-mail] (John Nagle) writes:

>       After the first shuttle flights, it turned out, as I recall, that
>the thermal protection requirements had been somewhat overestimated, and
>that titanium-based thermal protection would have worked.

No, I don't think that's a fair statement.  Some engineers
believed -- even before the first flight -- that high-
temperature refractory metals could have been made to work,
given enough cleverness. But I don't think there's any
general agreement on that.  The tiles were, and are, a
more conservative approach.

>I think Buran uses titanium, avoiding all those annoying problems
>with machining and glueing ceramics.

Nope.  The Soviets converted a bathroom-tile factory for Buran.
(There was a shortage of bathroom tile all over the Soviet Union
for months thereafter.)  Those who have seen the Buran tiles say
they have about the same density and thickness as bathroom tile.

>       There's been some recent Japanese work on the next step after
>composite materials, materials whose composition changes through the
>material.  Materials have been fabricated that are ceramic on one
>surface and metal at the other, with a smooth transition in between.

Interesting.  Is there a description of this work available
in English?

------------------------------

Date: Wed, 3 Feb 1993 04:10:00 GMT
From: Nick Szabo <[e-mail]>
Subject: Silly distortions of the Japanese space program
Newsgroups: sci.space

[e-mail] (Edward V. Wright) writes:

>Well, the Japanese construction industry thinks it could do
>the job for around one billion.

By "the Japanese construction industry" you mean one particular
person, the senile head of the Shimuzu Corp., who pours his
money into publications promoting his various cliched,
grandiose ideas.  For example this "space hotel", which is not
signficantly different from the fanciful hotel in the movie
_2001_.  The company itself has no interest or expertise in
the space industry, nor does Mr. Shimuzu himself have much money
to invest in anything beyond silly hype rags.  The major Japanese
corporate and government space organizations also have no interest
in this nonsense.

As for important Japanese effort, the Japanese government spends less
than 1/10 what the U.S.  government spends on space.  Their major
efforts are a commercial satellite launcher, a small but efficient
automated spacecraft program, and a tiny astronaut program that gloms
onto U.S. efforts.  They're spending less than 1/10 what NASA will
spend on SSF but expect to share in all the science results
and most of the engineering know-how.  Even with that incredible
discount they probably won't get their money's worth.


--
Nick Szabo                     [e-mail]

------------------------------

Date: Wed, 3 Feb 1993 22:17:33 GMT
From: Bruce Dunn <[e-mail]>
Subject: Space Station Freedom Media Handbook - 9/18
Newsgroups: sci.space

From NASA SPACELINK:

Space Station Freedom Media Handbook

"6_10_2_6_2.TXT" (26275 bytes) was created on 10-06-92

Marshall Space Flight Center

Traditional Center Roles and Responsibilities

The Marshall Space Flight Center in Huntsville, Alabama, was
established July 1, 1960, through the transfer to NASA of part
of the U.S. Army Ballistic Missile Agency. The Center was named
in honor of General George C. Marshall, the Army Chief of Staff
during World War II, Secretary of State and Nobel Prize Winner for his
world-renowned "Marshall Plan." Rocket pioneer Dr. Wernher von Braun
was the Center's first director.

Marshall is well-prepared for its Freedom Station responsibilities,
having managed America's first space station, Skylab, which was
launched in 1973. In addition to having overall program
management of Skylab, Marshall was responsible for much of
Skylab's hardware and science experiment development and for the
integration of the hardware and experiments into Skylab.
Marshall is also NASA's lead Center for Spacelab, a Space Shuttle-
based, short-stay space station that is serving as a stepping stone to
the permanently-manned Freedom Station. Marshall developed
selected Spacelab hardware and provided technical and
programmatic monitoring of the international Spacelab development
effort. The Center is also responsible for managing many Spacelab
missions that include developing mission plans, integrating payloads,
training payload crews and controlling payload operations. Marshall
is the home of NASA's Payload Operations Control Center (POCC) from
which Spacelab and other major science missions are controlled.
The Marshall Center has managed many successful space projects
since its creation nearly three decades ago. It provided the Redstone
rocket that put Alan Shepard into space in 1961. It developed the
Saturn family of rockets that boosted man to the moon in 1969.
Saturns were also used in 1973 and 1974 to launch Skylab as well as
Skylab crews, and in 1975 to carry the Apollo spacecraft into Earth
orbit for the historic link-up with the Russian Soyuz spacecraft.
Marshall payloads have included the three Pegasus micrometeoroid
detection satellites (1965); the Lunar Roving Vehicle (1971) for use
on the lunar surface; and the High Energy Astronomy Observatories
launched in 1977, 1978 and 1979 to study stars and star-like
objects.

In helping to reach the nation's present and future goals in space, the
Center is working on more projects today than at any time in its
history. In addition to its Space Station Freedom and Spacelab roles,
Marshall provides the Space Shuttle main engines, the external tank
and solid rocket boosters for each Shuttle mission. Marshall was
NASA's lead Cente for the development of the Hubble Space
Telescope (HST), which was launched in June 1990. GSFC now has
lead for operations of the HST.

Other current Marshall projects include the Advanced Solid Rocket
Motor (ASRM); the Advanced X-Ray Astrophysics Facility (AXAF); the
Inertial Upper Stage (IUS); the Transfer Orbit Stage (TOS); and the
Tethered Satellite System.

The Marshall Center is working to develop a heavy lift launch
vehicle, a new launch system, with joint participation with the U.S.
Air Force. Other future-oriented programs include studies focusing
on missions to Mars, a return to the moon and establishment of bases
on both bodies, and a series of Earth-observing experiments and
space-based facilities to help us protect our environment and more
fully understand the planet on which we live. Marshall facilities in
Huntsville include structural and test firing facilities for large space
systems, unique and specialized laboratories for a wide variety of
studies, and facilities for assembling and testing large space
hardware. It also operates the Michoud Assembly Facility in New
Orleans, Slidell Computer Complex in Louisiana, and tests Space
Shuttle main engines at the Stennis Space Center in Mississippi.

Space Station Freedom Unique Activities

U.S. Laboratory Module
Marshall is responsible for the U.S. Laboratory Module, capable of
supporting multidiscipline payloads, including materials research,
development and processing, life sciences research and other space
science investigations in a shirt-sleeve pressurized volume. The U.S.
Laboratory Module supports payloads provided by the scientific
community, such as furnaces for growing semiconductor
crystals, electrokinetic devices for separating pharmaceuticals,
support equipment for low-gravity experiments and life sciences
gravitational biology and space physiology.

Habitation Module
Marshall is responsible for the Habitation Module which includes
facilities for eating, sleeping, personal hygiene, waste management,
recreation and other habitation functions requiring pressurized
space. The same size as the U.S. Laboratory, the Habitation Module is
able to accommodate up to four astronauts at PMC. In addition, the
Habitation Module and the U.S. Laboratory Module provide
housekeeping functions, i.e., power distribution, heat rejection,
audio/video for crew and payloads.

Logistics Elements
Marshall is responsible for the logistics elements required for the
transport of cargo to and from the station, for resupply of items
required for crew, station and customers; and for the on-orbit
storage of these cargoes. A key element will be the Mini Pressurized
Logistics Carrier (built by Italy under direction of Marshall) at MTC
and the Pressurized Logistics Carrier at PMC to carry items used
inside the pressurized modules. Other elements include
Unpressurized Logistics Carriers for the transport of spares, fluids,
propellants and dry cargo, used outside the pressurized modules.

Resource Node Structure
Marshall is responsible for the structure of the resource nodes,
required to interconnect the primary pressurized elements of the
manned portion of Space Station Freedom. Resource nodes also house
key control functions and support experiments. Marshall provides
the resource node structures, berthing mechanisms, racks, the ECLSS
system, fluid management system, internal thermal control, internal
audio and video communication systems and manned-systems
subsystems, components and hardware. After PMC, the 2.5 m.
centrifuge will be located in the endcone of Node 3. It will also house
the habitats and systems.

Environmental Control & Life Support, Internal Thermal Control, and
Audio/Video Systems
Marshall is responsible for the Environmental Control and Life
Support System (ECLSS). The ECLSS provides a shirt-sleeve
environment for the astronauts in all the pressurized modules of
Space Station Freedom. A key feature of the ECLSS is the
regenerative design in the water reclamation system. Freedom
Station's internal thermal control and audio/video systems are also
provided by Marshall.

Elements and Systems

U.S. Laboratory Module
The U.S. Laboratory Module is a pressurized cylinder, about 27.44 ft.
(8.2 m.) long and 14.5 ft. (4.42 m.) in diameter, located below the
lower face of the transverse boom and attached perpendicular and
just to the left of center on the boom. It provides a shirt-sleeve
environment for crewmembers engaged in research and
experimentation. This location accommodates the microgravity
research needs.

Purpose
The U.S. Laboratory Module is dedicated to accommodating
multidiscipline payloads within a pressurized habitable volume.
Principal types of activity include:

*       materials research and development most sensitive to
acceleration;

*       research in basic science requiring long duration of extremely
low acceleration levels;

*       life sciences research relating to long duration exposure to
microgravity;

*       control and monitoring of user-provided pressurized payloads
and selected external attached payloads;

*       the intravehicular activity (IVA) including maintenance and
servicing of orbital replacement units (ORUs), instruments, and
equipment requiring workbench support in a pressurized volume.

The Laboratory Module has an atmospheric pressure of 10.2 psi at
MTC and 14.7 psi at PMC. The lower pressure enables the astronauts
to spend less time prebreathing before performing the EVA activities
which will be needed during the construction of the station. The
higher pressure is equivalent to sea level pressure.
It has 24 racks of which 12 are standard payload racks. The
remaining 12 rack positions accommodate such systems as the
environmental control and life support system (ECLSS), thermal
control system (TCS), manned systems and electrical power system
(EPS).

Design
The U.S. Laboratory Module uses a common design that is the prime
building block for all the pressurized modules, based upon proven
materials and processes. The approach results in a commonality of
parts, assemblies, components and systems, leading to simplified
manufacturing processes, a reduction in spares and ease of
maintenance. Design commonality also means that about 80 percent
of the hardware needed for the station's life support systems will be
common in the U.S. Laboratory Module, the Habitation Module, the
Pressurized Logistics Module and the Resource Nodes. Furthermore,
commonality of design and architectural continuity adds to a sense of
familiar surroundings for the crew. A pleasing environment enhances
crew productivity and a feeling of well being.

The modular design of the station means that some components can
be moved from one module to another, or to the Resource Nodes, as
the station evolves and needs change. Designed with the user in
mind, the Laboratory Module is segmented by work activity. For
example, materials science payloads and supporting equipment are
co-located. Material scientists need glove boxes, ultra pure water and
fluid handling tools. Life sciences payloads are also co-located. Life
scientists also need special equipment. Outfitting racks are designed
to tilt down for servicing, replacement, cleaning and transfer to other
modules.

Structure
The U.S. Laboratory Module consists of primary and secondary
structures. The primary structure consists of a pressurized shell, and
a meteoroid shield. Sandwiched between these two layers is
multilayer insulation for thermal protection. The exterior will also
have attachment points and grappling fixtures.

The secondary structure consists of mounting hardware that
provides rigidity for attaching outfitting packages and other
equipment to the pressurized shell. Utility lines are also mounted to
this secondary structure.

The Habitation Module
The United States provides the living quarters for use by all the
astronauts. The Habitation Module is an environmentally protected
enclosure intended for long duration crew activity and habitation
functions like eating, sleeping, relaxation and some work activities. It
is the same size as the U.S. Laboratory Module and provides the same
shirt-sleeve environment. The Habitation Module is located parallel
and next to the U.S. Laboratory Module in the cluster of pressurized
modules that make up the manned base.

The Habitation Module has internal audio and video, data and
information handling, and utility distribution and control. The floor
and ceiling are used for stowage, equipment, and provisions for crew
and daily operations. The interior of the Habitation Module is
outfitted for cooking, sleeping, personal hygiene, and other human
needs. At one end of the module are the galley and wardroom. The
galley is equipped with an oven, refrigerator/freezer, trash
compactor, hand washer and water supply. The wardroom, equipped
with windows, is an area for entertainment, eating and meetings. The
middle of the Habitation Module is devoted to hygiene with a
bathroom and shower.

Special attention is devoted to the Habitation Module to ensure a
"crew friendly" environment. Knowledge, materials and techniques
learned from previous space flights and airplane cabin technology
will keep noise levels at about 50 decibels--as quiet as a whisper. The
crew will sleep in attached sleeping bags in the aisle of the module
after PMC.

The Habitation Module is designed for four crewmembers. The
tabletop panels adjust to provide various seating arrangements for
the entire crew for meals, meetings, games, relaxation or
teleconferencing. Because work schedules are expected to be
scattered, two members of the crew may be eating supper while two
others are eating breakfast.

The exterior and shells for meteoroid and radiation protection are
similar to those of the U.S. Laboratory Module. Thus, the "Hab and
Lab" Modules are made from the same materials and same basic
designs, resulting in commonality and an estimated 20 percent cost
savings.

While there is no up or down in weightless space, the Habitation
Module does resemble an ultramodern, Earth-bound kitchen, den and
entertainment center. The notable exception is the vertical sleep
restraint system in place of bunk beds. See the JSC section for more
on outfitting the Habitation Module.

Logistics Elements
Logistics elements are cargo canisters attached to the station truss or
to a node. They are designed to be exchanged rather than refilled,
containing either dry or fluid material. The combination of cargoes
will vary for each flight to and from the station, depending on
requirements of the crew, station and customers.

Basically, Space Station Freedom requires two kinds of logistics
elements: pressurized and unpressurized. Both are needed in the
transport of equipment, supplies and fluids to the station, and to
return experiment results, equipment and waste products back to
Earth. These carriers provide the logistics for the ground-to-orbit,
on-orbit supply and storage, and return-to-ground requirements of
the station. They are designed to fit in the cargo bay of the Space
Shuttle.

Pressurized Logistics Carriers (PLCs)
The basic purpose of the PLCs is to provide ready, on-orbit access to
cargo without extravehicular activity. That means a PLC is a
habitable environment, providing a benign, temporary storage
facility for cargo. Thus, a PLC contains all the electrical, thermal, and
air quality requirements of an inhabited module. It will transport
cargo requiring a pressurized environment to the station, and then
transport equipment, products, biological products and waste from
the station. The interchangeable racks contain consumables, spare
parts, experiment parts and orbital replacement units (ORUs). The
ORUs are modular components of the station that can be easily
removed and replaced.

Unpressurized Logistics Carriers (ULCs)
Other ORUs, payloads and equipment are used in an unpressurized
environment. Therefore, several unpressurized logistics carriers will
be berthed at station ports. Typical contents in the ULCs include dry
cargo; ORUs for station, payloads and platforms; payloads and
experiments for the station and platforms; and fluids for the crew,
payloads and the ECLSS.

Depending on the particular logistics resupply requirements for that
flight, an arriving logistics element containing resupplies may be
exchanged with a berthed logistics element that has been packed
with equipment no longer needed, experiment results, trash, etc., and
readied for return to Earth. The newly arrived logistics elements will
be transferred to the station, hooked up and checked out before the
returning element is removed from the station and loaded into the
Shuttle cargo bay for the return trip to Earth.

A Pressurized Logistics Carrier will be located on the nadir of the
station--that is, in the direction of the Earth. The PLC, structured like
the nodes and modules for commonality of manufacture and design,
will be cylindrical with conical ends. It will be berthed at either Node
1 or Node 2.

The ULCs will berth out on the truss. The diameter of the ULCs will,
of course, be no wider than the Shuttle's cargo bay, and their lengths
may vary. The ULCs will contain dry cargo, gases and fluids. As the
station evolves, additional carriers will be required for
enhancements to the power or thermal systems, longer duration
missions and, possibly, the refueling and resupply of spacecraft that
stop off at Space Station Freedom on a mission to Mars and beyond.
PLCs and ULCs are being built at Marshall. The PLCs feature a
portable inventory system plus a lightweight plug door, and a roller
floor to reduce ground handling time. The ULCs are designed to
accommodate modularized fluids and modularized dry cargo in many
combinations.

Mini Pressurized Logistics Modules
The Italian Space Agency (ASI) will design and develop two Mini
Pressurized Logistics Modules for the Space Station Freedom program
under a memorandum of understanding (MOU) signed with NASA on
December 6, 1991.

The Mini Pressurized Logistics Modules (MPLM) are capable of
transporting user payloads and resupply items in a pressurized
environment to the station and returning necessary items to the
ground. The MPLMs will be capable of remaining at the Space Station
Freedom until the arrival of the next pressurized logistics module.
The MPLMs will be used to transport user payload racks on the
utilization flights, during the MTC period. The first MPLM is currently
scheduled to be transported to the station by the Shuttle in May
1997 and the second in August 1997. Each MPLM will accommodate
seven racks. After PMC, the MPLMs will be augmented by the larger
PLMs.

The Italian aerospace firm Alenia Spazio will build the modules.
Boeing Defense and Space Group in Huntsville, Alabama, will act on
behalf of NASA as the systems engineering and integration manager.f

Environmental Control and Life Support System (ECLSS)
Marshall is responsible for the Environmental Control and Life
Support System (ECLSS) which is divided into seven distinct
subsystems:

1)      temperature and humidity control,
2)      atmosphere control and supply,
3)      atmosphere revitalization,
4)      water recovery and management,
5)      fire detection and suppression,
6)      waste management, and
7)      support for extravehicular activity.

Primarily, the ECLSS provides a habitable environment for crew and
biological experiment specimens.

The ECLSS represents a breakthrough in closed-loop life support,
necessary for long duration missions to Mars and beyond. Water is
recycled through the collection of H2O in both air and liquids, such as
urine and sweat. Available at PMC, the ECLSS produces a potable
grade of water, even from urine, for drinking, washing and cleansing.
Carbon dioxide is collected and vented to space. Waste products are
containerized and returned to Earth. There shall be no overboard
dumping of solids or liquids. Because of leakage and process losses,
all quantities of oxygen, nitrogen and water must be resupplied from
Earth.

The hardware for the ECLSS is distributed throughout the
pressurized modules to assure sea-level pressure, temperature,
humidity and air composition; as well as water, and fire
detection/suppression equipment. For redundancy, repressurization
and fire fighting equipment are located in both the Habitation and
Laboratory Modules. Design challenges for the remainder of this
decade include the ability of the ECLSS to maintain microbial and
chemical system cleanliness during extended duration missions and
multiple reuses of water supplies.

The ECLSS will collect, process and dispense water as required, to
meet the needs of the crew and any other users. It will pretreat
waste water in order to prevent chemical breakdown and the growth
of microbes. Post-treatment systems and a water quality monitoring
system will ensure that the water provided to users is of sufficient
quality.

Waste management is another important function of the ECLSS.
Waste products (e.g., metabolic waste, food, packaging, regenerative
process effluents, hard copy waste, etc.) will be collected and
processed for conversions to useful products or returned to Earth.
Venting of gases shall be controlled so as to avoid contamination or
degradation of the exterior shells of modules, not to mention exposed
payloads out on the truss.

The ECLSS will provide support for servicing the Extravehicular
Mobility Unit (EMU), the Extravehicular Excursion Unit, and the EVA
systems. It will provide the depressurization and repressurization of
the airlock. An interface will exist between the ECLSS and the
Thermal Control System (TCS) for the removal of heat from the
atmosphere of the pressurized elements.

Commonality is stressed as the ECLSS is built into each of the U.S.
Laboratory and Habitation Modules, nodes and the pressurized
logistics carrier. This commonality reduces manufacturing costs,
lightens the load for spare parts and makes repairs simpler and
quicker. In the event of an accident or malfunction, the ECLSS is built
with redundant life-critical hardware in the U.S. modules.
The ECLSS represents design challenges not seen on previous space
programs. The requirements for closed loop air and water systems
extend human duration in space and reduce resupply flights
significantly.

Resource Node Structure
Resource nodes are required to interconnect the primary pressurized
elements of Space Station Freedom. As such, they also house key
controls for operations.

A resource node is a pressurized volume and an environmentally
controlled enclosure. It is also a center for Space Station Freedom
command, control and operations. Distributed subsystems are located
and controlled here at workstations. The two resource nodes, located
at the ends of the U.S. Laboratory and Habitation Modules, provide a
pressurized passageway to and from the modules and an interface to
the Space Shuttle.

Built like the other pressurized modules, the nodes will be smaller,
about 17 feet (5.2 meters) long and 14.5 feet (4.42 meters) in
diameter. They will reduce the amount of EVA time required to
assemble the station. The nodes are designed and built by Marshall
Space Flight Center and outfitted by Johnson Space Center. Each node
is a pressurized, environmentally controlled element designed to
perform a variety of activities:

*       passage of crew and equipment,
*       station command and control functions,
*       external view for berthing and proximity operation,
*       IVA control and monitoring electronics for the MSS,
*       residence for station distributed systems,
*       limited station storage,
*       residence for supporting utility systems equipment,
*       limited user payload operation,
*       residence for the centrifuge, and
*       residence for the Crew Health Care System.

The first node to be launched, Node 2, is located between the U.S.
Laboratory Module and the Japanese Experiment Module (JEM). It
contains the primary command control workstation and provides
integrated avionics racks to perform data management, thermal
control, communications and tracking and electrical power
monitoring and control. Node 2 provides ports for the airlock,
pressurized logistics module, cupola and Node 1. Node 2 is available
at MTC.

The second node to be launched, Node 1 is attached to the starboard
port of Node 2 and provides ports for the Habitation Module, the
Columbus Laboratory, the Pressurized Logistics Module and the
Assured Crew Return Vehicle. It contains the secondary command
control workstation and other integrated avionics racks which
distribute electrical power, data management, audio/video and
communications and tracking resources.

The cupola is being designed for maximum viewing with both
portable and installed command and control consoles. It will be
attached to the outboard port of a resource node. It can be used for
observations during shuttle berthing and attached payload servicing.
It will accommodate two astronauts. A cupola cover can extend to
provide micrometeoroid and debris protection.

Facilities

Payload Operations Integration Center
The Payload Operations Integration Center (POIC) will be used to
manage or control realtime research operations, interfacing with the
Space Station Control Center in Houston, Texas and various user
facilities in other communities. As a control central point for payload
operations, the POIC will integrate science operation centers and will
house computer systems for realtime operation, the mission planning
system and analytical tools.

Engineering Support Center
The Engineering Support Center (ESC), an adjunct to the Huntsville
Operations Support Center (HOSC), will provide Work Package 1
engineering support for realtime operations. The ESC serves as a
control point for requests from the SSCC and the POIC for engineering
support to operations. It also supports the engineering flight
evaluation and anomaly resolution for Space Station Freedom.

Payload Training Complex
The Payload Training Complex (PTC) will provide for the
development, maintenance, and verification of payload operations
training, including the hardware and software to support the training
of payload crew, Payload Operations Integration Center personnel,
experimenters and users.

Space Station Freedom Organization

The Marshall Space Flight Center (MSFC) in Huntsville, Alabama has
been designated as the Work Package 1 Center. Work Package 1
includes the design and manufacture of the astronaut's living
quarters, known as the Habitation Module; the U.S. Laboratory
Module; logistics elements used for resupply and storage; node
structures connecting the modules; the Environmental Control and
Life Support System, and the Internal Thermal Control and
Audio/Video Systems located within the pressurized modules.
MSFC has established the Level III Space Station Freedom Projects
Office to manage and direct the various design, development and
operational activities needed to successfully complete the Work
Package 1 assignment.

A unique aspect of this organization is its emphasis upon
Environmental Control and Life Support Systems in spaceflight.
Preparing accommodations for a crew of four for 90-day stretches is
vastly complex, but to develop the world's first closed-loop life
support system is a real challenge for Marshall Space Flight Center,
preparing the U.S. for longer duration missions to Mars and beyond.

The material above is one of many files from SPACELINK
A Space-Related Informational Database
Provided by the NASA Educational Affairs Division
Operated by the Marshall Space Flight Center
On a Data General ECLIPSE MV7800 Minicomputer

SPACELINK may be contacted in three ways:

1) Using a modem, by phone at 205-895-0028

2) Using Telnet, at spacelink.msfc.nasa.gov

3) Using FTP capability. Username is anonymous and Password is guest.
Address is 192.149.89.61.



--
Bruce Dunn    Vancouver, Canada   [e-mail]

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End of Space Digest Volume 16 : Issue 127
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