3/21/91: SPACE STATION FREEDOM RESTRUCTURING PLAN COMPLETED RELEASE: 91-45 NASA today delivered the "restructuring" report to the Congress, outlining an extensive redesign of the Freedom space station. The new design is cheaper, smaller, easier to assemble in orbit and will require fewer Shuttle flights to build. Major new features of the redesigned space station - shorter U.S. laboratory and habitat modules that can be outfitted and verified on the ground and a pre-integrated truss that can be assembled on the ground and tested with all of its subsystems intact - will significantly reduce intravehicular activity (IVA) and on-orbit extravehicular activity (EVA) needed to build and maintain Freedom. "This new design for Space Station Freedom accomplishes every major goal we set for ourselves when we kicked off this effort last November," said William B. Lenoir, Associate Administrator for Space Flight. "We took the directions from Congress and the Augustine Commission recommendations to heart, and the program we are announcing today addresses each and every one of their requirements. "We've cut costs, simplified the design and reduced the complexity of the project. At the same time, Freedom will be a quality facility, providing a research laboratory unsurpassed in the world for life sciences and microgravity research, and a stepping stone into the future, enabling NASA to conduct the research and planning necessary for human exploration of the solar system. And, we have maintained our international commitments," he continued. A 1991 fiscal year budget shortfall of more than $550 million, along with Congressional directions to significantly reduce out-year spending, prompted NASA to begin the restructuring of Freedom. Congress told NASA to expect no more than 8 to 10 percent growth over the next 5 years (FY 1992-1996), with peak spending for Freedom not to exceed $2.5-2.6 billion. The budgetary ground rules, including the cut for FY 1991, represent a $5.7 billion shortfall from what NASA had planned to spend for Freedom over that same time period. NASA directed the review in November 1990 with instructions to the Freedom project team to: develop a phased approach with quasi-independent phases; protect life and materials science; maintain international agreements and capability; limit assembly flights to no more than four annually; and achieve first element launch, man-tended capability and permanently manned capability as early as possible. The restructured program calls for the first element launch of the space station to be made in the second quarter of FY 1996 (January - March 1996), and man-tended capability to be achieved in the third quarter of FY 1997 (April-June 1997). In the man-tended phase, astronauts brought up to Freedom by the Space Shuttle will be able to work inside the U.S. laboratory for periods of 2 weeks. They will return to Earth with the Shuttle. At this stage, one set of Freedom's solar arrays will generate about 22 kw of power with a minimum of 11 kw available to users. Six Shuttle flights will be required to achieve the man-tended configuration. Freedom will achieve a permanently manned configuration in Fiscal Year 2000. This configuration will consist of the U.S. laboratory and habitat, as well as the European and Japanese laboratories; the Canadian Mobile Servicing System; accommodations for a live-in crew of four; and three sets of solar arrays furnishing 65 kw of electrical power, with a minimum of 30 kw going to the users and the remainder to housekeeping chores. A new requirement before permanently occupying the station will be the availability of an Assured Crew Return Vehicle to return space station crew members to the Earth in an emergency. Seventeen Shuttle flights will be needed to build the permanently manned configuration. Provisions to expand the space station have been maintained. The follow-on phase of the Freedom program will include another solar array to achieve 75 kw, provisions for 4 additional crew members and could include additional capabilities such as a second preintegrated laboratory and additional nodes. This phase would use the new launch system for launch and assembly if the launch system is available. The redesigned U.S. lab and hab modules are 27 feet long and 14.5 feet in diameter, about 40 percent shorter than the previous design. The smaller size allows the modules to be fully outfitted and tested on the ground prior to being launched into orbit. The U.S. lab module will hold a total of 24 8-foot wide racks, 15 of which initially are devoted to scientific work. At permanently manned capability, 28 experiment racks will be available to U.S. investigators: 12 in the U.S. lab, 11 in the ESA lab and 5 in the Japanese lab. The redesigned truss segments will be built, preassembled and checked out on the ground. Formerly, the truss was to have been assembled, like a massive erector set, by astronauts performing space walks. NASA estimates the pre-integrated truss will cut assembly EVA by more than 50 percent. While work on the Attached Payload Accommodations Equipment (APAE) suitable for large external payloads has been stopped, utility ports for small external payloads will be placed along the truss. The overall width of the station has been reduced from 493 feet to 353 feet. Complexity of other station systems also has been reduced and where possible, hardware already flying on the Space Shuttle will be used in place of developing new hardware for the station. Also called for in the plan is the transfer of the Flight Telerobotic Servicer to NASA's Office of Aeronautics, Exploration and Technology. This, together with the deferral of the APAE, has eliminated the Goddard Space Flight Center's Work Package 3 from the Freedom program. In addition to changes to the flight hardware, a number of changes to ground facilities are planned. The Space Station Processing Facility to be built at the Kennedy Space Center will not be fully outfitted, and a new hazardous processing facility has been deleted in favor of using an existing facility. The size of planned facilities at the Johnson Space Center - the control center and crew training facilities - have been scaled back. Payload facilities at Marshall Space Flight Center are being deferred and existing facilities will be used in the interim. Due to funding cutbacks and hardware changes in the program, some layoffs of prime and subcontractor personal have already taken place, and more are expected. At Work Package 1, no layoffs at the prime contractor, Boeing, are expected, but more than 500 people will be reduced from the subcontractor roles, some of which will be accommodated through transfers and attrition. At Work Package 2, prime contractor McDonnell Douglas has already reduced its work force by about 160, with half that number being layoffs. Major subcontractors to McDonnell Douglas will be reduced by about 470, with layoffs accounting for approximately half of that, and another 200 will be reduced from supporting development, with about 65 of that total coming from terminations. At Work Package 4, no layoffs are expected, but as many as 40 people in support jobs at Lewis Research Center will be reassigned. Layoffs of about 30 percent of the work force at the Space Station Engineering and Integration Contractor, Grumman, were announced earlier this month. SPACE STATION FACT SHEET SPACE STATION FREEDOM WORK PACKAGES SPACE STATION FREEDOM WORK PACKAGE ONE NASA's Marshall Space Flight Center (Work Package 1) has responsibility for: the design and construction of Space Station Freedom's pressurized laboratory and habitation modules, the working area and living quarters for Freedom's crew members; the logistics modules, used for resupply and storage; node structures, which connect the laboratory and habitation modules; and certain subsystems internal to the pressurized modules, including the environmental control and life support, thermal control, electrical distribution, communcations and audio/video systems. UNITED STATES LABORATORY AND HABITATION MODULES The U.S. Laboratory Module and Habitation Module will each be 14.5 feet in diameter and 27 feet in length. These dimensions allow the modules to be built, outfitted, integrated and tested on the ground and then transported into Earth orbit in the Space Shuttle cargo bay and connected to the nodes and other space station structures. The U.S. Lab will include 15 experiment racks and 13 systems racks. During the station's Man-Tended Capability (MTC) phase, this orbiting laboratory will serve as the site for microgravity research and will be capable of conducting that science in both a manned mode, when astronauts are visiting the station via the Space Shuttle, and in an unmanned mode. When station construction reaches Permanently Manned Capability (PMC) and four astronauts remain onboard for extended periods, life sciences research will be conducted to learn more about the affects of living in space and to help prepare mankind for returning to the Moon and exploring the planets. With the addition of the Habitation and International Laboratory modules, the station's module racks will expand to as many as 45. When station construction reaches PMC and the Hab Module is added, Freedom's environmental control and lifes support systems will provide closed-loop water recycling capability. The crew's food and other supplies will be carried to the station via a logistics module which is transported in the Space Shuttle's cargo bay. During the Man-Tended Capability phase, astronauts visiting Freedom will live on the Shuttle. SPACE STATION FREEDOM WORK PACKAGE TWO NASA's Johnson Space Center (Work Package 2) Space Station Freedom Program Office (SSPO) is responsible for the design, development, verification, assembly and delivery of the Work Package 2 flight elements and systems, which include: the pre-integrated truss assembly; propulsion assembly; Mobile Servicing System transporter; resource node design and outfitting; external thermal control; data management; communication and tracking; extravehicular systems and guidance; navigation and control systems, and the airlock. JSC SSPO is also responsible for the attachment systems required by the Space Shuttle for periodic visits. In addition, JSC SSPO provides technical direction to the Work Package 1 contractor via the Marshall Space Flight Center for the design and development of all manned space subsystems. PRE-INTEGRATED TRUSS ASSEMBLY The pre-integrated truss assembly is the Space Station Freedom structural framework to which the modules, solar power arrays and mobile transporter will be attached. PROPULSION ASSEMBLY The propulsion assembly will be used to adjust or maintain the orbit of Space Station Freedom to ensure it remains at the required altitude. Work Package 2 has responsibility for the overall propulsion system. MOBILE TRANSPORTER SYSTEM The Mobile Servicing System will be a multi-purpose mechanism equipped with a transportable robotic arm used to help assemble and maintain Space Station Freedom. The Work Package 2 contractor will build the mobile transporter; Canada will provide the robotic arm and a special-purpose dexterous manipulator. RESOURCE NODES The resource nodes house most of the command and control systems for the Space Station as well as being the connecting passageways for the habitation and laboratory modules. Work Package 2 will outfit the node structures provided by Work Package 1 to accomplish the objectives of each node. EXTRAVEHICULAR ACTIVITY SYSTEMS Extravehicular activity (EVA) systems includes equipment such as the extravehicular mobility unit (EMU) or spacesuit; provisions for communication; physiological monitoring and data transmission; EVA crew rescue and equipment retrieval provision and EVA procedures. An airlock for use by crew members performing EVA will also be designed as part of Work Package 2. EXTERNAL THERMAL CONTROL The external thermal system provides primary cooling and heat rejection to control temperatures of electronics and other Space Station hardware located throughout the facility. ATTACHMENT SYSTEMS In concert with the Orbiter Projects Office, Work Package 2 is responsible for the development of systems which will permit Space Shuttle mating with the Space Station. GUIDANCE, NAVIGATION AND CONTROL SYSTEM The GN&C system is composed of core system and traffic management functions. The core system function provides attitude and orbital state maintenance; supports the pointing of the power system and thermal radiators; accomplishes periodic reboost maneuvers, and provides Space Station attitude information to other systems and users. The traffic management function provides for controlling all traffic in the area around the Space Station, including orbiter mating operations and trajectories determination of vehicles and objects which may intersect the orbit of the Space Station. COMMUNICATIONS AND TRACKING SYSTEM The communications and tracking (C&T) system is composed of six subsystems: space-to-space communications with crew members during space walks (EVA); aboard the Space Shuttle, and with visiting vehicles such as the European Space Agency man-tended free-flyer; space-to-ground communications through the Tracking and Data Relay Satellite System (TDRSS) to ground data networks; internal and external voice communication through the audio subsystem; internal and external video requirements through the video subsystem; management of communication and tracking resources and data distribution through the control and monitor subsystem; and navigation data through the tracking subsystem. DATA MANAGEMENT SYSTEM The data management system (DMS) provides the hardware and software resources that interconnect onboard systems, payloads, and operations to perform data and information management. Functional services provided by DMS include data processing, data acquisition and distribution, data storage, and the user interface to permit control and monitoring of systems and experiments. ASSURED CREW RETURN CAPABILITY Crew safety is an essential consideration in the development of the Space Station to the permanently-manned configuration. A major system failure aboard the Space Station, injuries or illness may require the return of crew members to Earth during a period when the Space Shuttle is unavailable. NASA's Johnson Space Center has responsibility for conducting definition-phase studies of an Assured Crew Return Vehicle (ACRV) which would be used to supplement the Space Shuttle in such circumstances. WORK PACKAGE TWO CONTRACT McDonnell Douglas Space Systems Company's Space Station Division heads a team completing the work for Work Package 2. Major subcontractors include GE Aerospace Government Communications Systems Division, Honeywell Space Systems Group, IBM Federal Sector Division, Lockheed Missiles and Space Company and Astro Aerospace. GE is producing communications and tracking, Honeywell is working on stabilization and controls, IBM is designing the data management systems, Lockheed is developing thermal control, power management and distribution, and extravehicular activity systems, and Astro is responsible for the mobile transporter system. SPACE STATION FREEDOM WORK PACKAGE FOUR NASAUs Lewis Research Center, Cleveland, Ohio, is responsible for the end-to- end electric power system for the Freedom space station. This includes defining the system architecture and providing the solar arrays, batteries, and power management and distribution hardware and software. The power system includes power generation and storage, and the management and distribution of power to the final user interface. The electric power system is required to have the capability to deliver 22 kW of electric power for a man-tended configuration, and 65 kW for a permanently manned configuration with growth to 75.0 kW. POWER GENERATION Initially, power for Freedom will be provided by flexible, deployable solar array wings. This configuration minimizes the complexity of the assembly process by taking advantage of the technology previously demonstrated on Space Shuttle flights. Each 39-by-122 foot wing consists of two blanket assemblies covered with solar cells. These are stowed in blanket boxes which are attached to a deployment canister. Each pair of blankets is to be deployed and supported on a deployable mast. A tension mechanism will supply tension to the blanket as it reaches complete extension. The entire wing will be tied structurally to the pre-integrated truss by means of the beta gimbal assembly. In order to provide the power needed during the period of space station assembly, two solar wings, the energy storage system and electronics components are assembled into a power module scheduled to be carried up on the first space staion assembly flight. These two wings along with engergy storage will provide 22 kW of power. The remaining power modules with two solar array wings per module will be delivered on oribit after the man-tended configuration is reached. POWER STORAGE Nickel Hydrogen (Ni-H2) batteries will store the energy produced by the solar arrays. A battery pack is made up of 76 Ni-H2 cells, wiring harness, and mechanical/thermal. support components. On discharge, the battery provides power to the primary bus for eclipse periods. Ni-H2 batteries were selected for low weight and high reliability. POWER MANAGEMENT AND DISTRIBUTION (PMAD) The 160/120 volt DC PMAD system is designed specifically to meet the high electric power system requirements of the space station. It is user friendly and can accommodate a wide variety of user loads delivering controlled power to many scattered loads. The high voltage DC power system was selected to provide high efficiency, low cost, and safe operations.