Date: Thu, 4 Feb 93 05:31:28 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu 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 "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 3 Feb 1993 16:58:12 -0500 From: Matthew DeLuca Subject: An 'agitator' replies (was: Clinton's Promises...) Newsgroups: sci.space In article <1993Feb3.213208.25752@iti.org> aws@iti.org (Allen W. Sherzer) writes: >In article <1kn9p0INN2dm@phantom.gatech.edu> matthew@phantom.gatech.edu (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: matthew@phantom.gatech.edu ------------------------------ Date: Wed, 3 Feb 1993 04:31:40 GMT From: Nick Szabo Subject: Goals for year 2000. I have a dream. Newsgroups: sci.space nsmca@acad3.alaska.edu 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 szabo@techboook.com ------------------------------ Date: Wed, 3 Feb 1993 21:26:16 GMT From: fred j mccall 575-3539 Subject: parachutes on Challenger? Newsgroups: sci.space In <1993Feb3.153255.13816@ke4zv.uucp> gary@ke4zv.uucp (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 ------------------------------------------------------------------------------ Fred.McCall@dseg.ti.com - 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 Subject: Riding Comets Newsgroups: sci.space aa429@freenet.carleton.ca (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 szabo@techboook.com ------------------------------ Date: 3 Feb 93 22:01:41 GMT From: "Edward V. Wright" Subject: Shuttle tiles Newsgroups: sci.space In <1993Feb3.054618.19369@netcom.com> nagle@netcom.com (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 Subject: Silly distortions of the Japanese space program Newsgroups: sci.space ewright@convex.com (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 szabo@techboook.com ------------------------------ Date: Wed, 3 Feb 1993 22:17:33 GMT From: Bruce Dunn 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 Bruce_Dunn@mindlink.bc.ca ------------------------------ End of Space Digest Volume 16 : Issue 127 ------------------------------