April 1991 "Station Break" Space Station Freedom Newsletter Congress Approves Modified Space Station New Design Features shorter, pre-integrated truss and modules NASA 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. "We've come out of this with a space station we can be proud of, a space station we can do. We know we can do it. We now need stability in funding to turn it into reality," Dr. William B. Lenoir, associate administrator for space flight said at a press conference last month. "This new design for Space Station Freedom accomplishes every major goal we set for ourselves when we kicked off this effort last November," Lenoir said. "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 (fiscal year 1992-1996), with peak spending for Freedom not to exceed $2.5-2.6 billion. The budgetary ground rules, including the cut for fiscal year 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 fiscal year 1996 (January - March 1996), and man-tended capability to be achieved in the third quarter of fiscal year 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 Eu-ropean 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 pre-integrated 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. Form-erly, 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 facili-ties 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. SSAC to Oversee Restructured Station After preliminary approval of a newly modified Space Station Freedom, the Space Station Advisory Committee (SSAC) last month accepted an armload of challenges from Office of Space Flight Associate Administrator Dr. William B. Lenoir to keep the program alert to potential problems. Lenoir asked committee members to continue to monitor: * the station's data management system and recommend ways to avoid possible glitches in the system; * system-level verification plans; * external and internal maintenance; * utilization flights; * induced environment, including microgravity; * assured crew return vehicle requirements and development and plans. Lauding the committee's past efforts to keep the program on its toes, Lenoir said, "NASA needs your assistance and expertise to help us know when we need to do things differently." The next SSAC meeting is slated for June. During two all-day meetings, the advisory committee was briefed by Space Station Freedom Director Richard Kohrs on the five-month-long restructure assessment study; Space Station Chief Scientist Dr. William Taylor on user accommodations; SSAC member Dr. Robert Bayuzick on how the Space Station Science and Applications Advisory Subcommittee reacted to restructuring (see story, page 3); SSAC member Dr. William C. Schneider on the Aerospace Medical Advisory Committee restructuring concerns, and; SSAC member John Miller on the status of the data management system. Kohrs told the committee that the program continues to work to ensure minimal impacts to the station users of power, rack space, crew availability, and data rates, etc. Kohrs also said, while the program will not preclude future long-term growth, it cannot afford to accommodate all of those requirements at this time. Despite some remaining concerns that continue to be worked, Taylor told committee members that the restructure assessment helped push improvements in several areas, such as microgravity, power, and rack availability. Taylor said that 20 percent of the U.S. laboratory would be within 1x10-6g, and 100 percent will be within 3x10-6g. In fact, Kohrs said, those numbers continue to improve. Taylor also said that NASA plans to provide an acceleration mapping system in the U.S. lab. Until permanently-manned capability in late 1999, Freedom will be maintained at 10.2 psia to reduce pre-breathe time for external maintenance activities. Some time later, after assembly, the station pressure will be increased to 14.7, Taylor said. Concerning the data management system, Miller pointed out a list of potential problems, and told Kohrs the program must address these to avoid future headaches. One of Miller's main concerns was the possible incompatibility of software because several different companies are developing programs for the station and its ground-support facilities. Other concerns include: * commercial off-the-shelf software upgrades provided to NASA may not have been validated by the manufacturers and thus could cause problems; * the probable cost of the necessary data management system kits is too high for the payload developers; * top-level requirements do not always appear in the design, and; * validation and verification of the hardware and software is needed, including analytical modeling, simulation under emergency conditions, prototype testing and validation, and multiple fault analysis of hardware will be difficult. ------------------------------------------------------------------- After Restructure Exercise, Station's Lab Remains Top-Notch Facility, PhDs Say When Space Station Freedom's budget had $550 million cut from its 1991 budget request of $2.45 billion to $1.9 billion and was ordered by Congress to reassess the station's design, many potential science users expected the worst. The worst did not happen, however, and the users can now breathe a sigh of relief, said Dr. William Taylor, Space Station Freedom chief scientist. As chief scientist, Taylor serves as a conduit to station managers about the concerns and requirements of scientists who are potential users of Freedom. Both Taylor and Dr. John-David Bartoe, director of Freedom's Operations and Utilization Division, say that the modified station design, which features shorter pre-integrated laboratory and habitation modules, and a shorter, pre-integrated truss, still will provide a top-flight facility for both life and materials scientists. "I feel the restructuring has turned out reasonably well," Taylor said. "We've had a good turn around from a low point at the beginning of this process. At first, it appeared that science was going to be significantly reduced, but we've been successful in retaining capabilities. "Of course, any reduction in resources is going to make the user community unhappy, but we think we've hit a happy medium that meets both the budget constraints and users' needs," Taylor said. During a Space, Science and Applications Advisory Subcommittee (SSSAAS) meeting in March, the subcommittee members's scientist characterized the overall space station restructure as a good move on NASA's part, but the group also said numerous concerns must be addressed before whole-hearted support is given. All of the concerns presented by the SSSAAS will be addressed during a June workshop, said Taylor. "We will either give them answers to their specific questions, or, because we may not be able to address all of their concerns by June, we will tell them how we're planning to answer those questions. In general, I'd say the user reaction to the restructuring was positive. They recognize the limitations imposed on the payloads were forced? by budget cuts." In a report presented to Freedom managers in March, the space science subcommittee said that it "finds many positive features in the restructured station and appreciates the response of the Space Station Freedom Program Office to the concerns expressed by our subcommittee in November 1990. "The potential for performing effective research in microgravity and life sciences in many ways is good. In particular, the maintenance of microgravity levels within specified limits throughout most of the U.S. laboratory and mapping of the g-levels are considered to be great improvements. "No less, exciting opportunities are provided by the availability of resources sufficient to carry out a significant research program in the untended intervals between utilizations flights . . . A number of issues now need to be addressed." The main concerns reflected in the space science subcommittee report to space station managers include resources such as power, crew, data management, utilization during the man-tended phase, pressurization, centrifuge facility, rack allocation, early use of racks for life science, and providing capabilityfor small- and medium-sized attached payloads. Potential station users, Taylor said, are most concerned about the availability of power, "particularly the materials science people," because their furnace experiments alone will consume at least a few kilowatts of power. "Historically," Taylor pointed out, "users have always been disappointed with the power available on spacecraft." Most researchers, Taylor said, are unaccustomed to rationing their power needs, because, in their Earth-bound laboratories, it is unnecessary. "Power now seems adequate for a much greater range of experiment scenarios," the SSSAAS said. While the power available to the users is generally acceptable, the the space science subcommittee said station designers must maintain discipline when designing subsystems because there is "no apparent margin" between what is required and what can be supplied. "We are holding the line at permanently-manned capability to 30 kilowatts or more for users," Taylor said. This compares to a maximum of 2.5 kilowatts available for users on Spacelab, which flies in the Shuttle's cargo bay, and the Skylab's average of 2.3 kilowatts. Second on the list of concerns for researchers is the available data-rate. "Before restructuring, the rate was 300 megabits per second, now they're talking 50 megabits downlink, which is like Spacelab," Taylor said. This decrease, naturally, leads to disappointment among the scientific community, he said. It does not mean that the 50 megabits per second is unworkable, he said. "I am fairly convinced that 50 megabits per second will be adequate," Taylor said. The lower data rate is attributed to using existing antenna technology for sending data from Freedom to Earth, rather than building a station-unique antenna, said Bartoe. The station itself will be built with the higher data-rate fiber-optics lines, so, as funding becomes available later on, the capability to send 300 megabits per second of data will be added back, he said. Third on the priority list for potential users, especially life scientists, is crew availability -- how many are aboard Freedom and how much time they can devote to research. If life sciences researchers are to cement their support for Freedom, then NASA must reaffirm its commitment to a permanent eight person crew, the report stated. Currently, the detailed planning through permanently manned capability can support about a four-person crew. "An eight person crew is critical to obtaining statistically valid data in human physiology in a reasonable time period," said the space science subcommittee report. "If the restructured design includes a commitment to permanent manning with a crew of four, growing to eight, the restructured space station will represent an invaluable life sciences space research facility," the report stated. Taylor emphasized that the program is committed to an eight-person crew, and more crew will live aboard Freedom as money becomes available. According to the Report of the Advisory Committee on the Future of the U.S. Space Program, also known as the Augustine Committee, "The need for the space station rests squarely upon life sciences experimentation and the development and verification of long duration space operating systems. These, together with its uses for microgravity research and applications are, in our opinion, a more than sufficient justification for space station." Although life sciences research alone justifies building Freedom, Bartoe said, it "would be a real mistake to do only that." Since Freedom is being built as a versatile research facility, it will be possible for a rainbow of differing projects to be conducted over Freedom's 30-year life. "If the station could afford to support only one major research effort, life sciences research would be it, because it is needed to overcome the problems of long-term human space flight," Bartoe said. "To build this large, multi-billion dollar program and not put humans in space -- well, then we should be doing something else. If microgravity research was all you wanted to do, then you could do that work on something like ESA's [European Space Agency's ] future man-tended free flyer," he said. The one discipline most affected by the space station restructure assessment is the observing sciences whose payloads must be attached to Freedom's exterior to either observe the Earth or deep space. Because the restructure assessment has postponed indefinitely the attached payloads accommodations equipment, some of the larger, more complicated payloads also must be deferred, Taylor said. This move has not precluded small- and medium-sized payloads, as well as rapid response payloads. "We think we should be able to accommodate some attached payloads, but the details must be worked out," Taylor said. The SSSAAS has recommended that the program accommodate some attached payloads by designing the standard utility ports, already planned for the pre-integrated truss, with mechanical attachments, data lines, environmental sensoring, and cooling. While life sciences researchers will have to delay long-term human physiology experiments until permanently-manned capability is achieved in 1999, other aspects of life science and materials science research will benefit, they said. For several years, materials scientists have been pushing station managers for "quiet time" aboard Freedom, so long-term materials experiments could be conducted without human disturbance, Dr. Robert J. Bayuzick, a Space Station Advisory Committee member, said at a March Space Station Advisory Committee meeting. Bayuzick is a professor at Vanderbilt University, Nashville, Tenn. "Every cloud has a silver lining and the microgravity science community can make early use of the space station in a relatively undisturbed state. This could provide us with a good acceleration to do work that will tell us what needs to be done, because this science is in its infancy," Bayuzick said at the meeting. "I've always pleaded for a window of opportunity and this may give us that window of opportunity." Between 1996 and 1999 when the Space Shuttle crews will visit Freedom for up to 13 days, known as the man-tended phase, an array of experimentation can be conducted in microgravity science and life sciences, as well as technology research, Bartoe said. Within the microgravity area, during the man-tended phase, researchers will expand their knowledge in fluid physics, improved inorganic crystals, and improved organic crystals. The life sciences will learn more about gravitational biology, animal biology, plant biology, controlled ecological life support systems, and human physiology. Advanced technology investigators willresearch very high-speed integrated circuit fault tolerance, acoustic technology, and flight dynamics. The permanently manned phase of the program, which will be ushered in during 1999, will bring even more research capabilities to Freedom's U.S. laboratory. The microgravity scientists will continue their research with "next generation" crystal growth, containerless processing, biotechnology, and advanced fluid physics, dynamics, and combustion. The life sciences will further investigate the intricacies of human cardiovascular and pulmonary physiology, radiobiology, neurophysiology, metabolism and nutrition, endocrinology, gravitational biology, and, the controlled ecological life support systems, among others. Advanced technology researchers will focus on microbiological monitoring, regenerative life support, risk-based fire safety, laboratory robotics, and materials dispersion studies. "As you can see, this is a lot of science," Bartoe said. And these are just the projects the program is planning, he emphasized, no one knows what research in any one of these areas will lead to. Centers Shift into High Gear to Hit Milestones Space Station Freedom's three project offices and their contractors, known as work packages, have primary responsibility for designing and manufacturing hardware. NASA's Marshall Space Flight Center and Boeing Defense and Space Group, Work Package 1, in Huntsville, Ala., is responsible for: the design and construction of Freedom's pressurized laboratory and habitation modules, the working and living areas for the crew; logistics modules, used for resupply and storage; node structures, which con-nect the laboratory and habitation modules; and certain subsystems internal to the pressurized modules, including the environmental control and life support,among others. NASA's Johnson Space Center and MacDonnell Douglas Space Systems Company, Work Package 2, in Houston 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, among others. NASA's Lewis Research Center, Cleveland, Ohio, and Rocketdyne Work Package 3, is responsible for the end-to-end electric power system. This includes defining the system architecture and providing the solar arrays, batteries, and power management and distribution systems. The power system includes power generation and storage. Vice President, Partners Support Restructure Vice President Dan Quayle and the space station international partners, in separate letters to NASA Administrator Richard Truly, lauded the program in its efforts to modify the station's design. "This new design reflects a focusing of the space station program that recognizes certain fiscal and physical realities. . . Implementing these changes will greatly increase the nation's confidence in the feasibility of this program," Quayle stated in a March 19 letter to Truly. "The importance of space station, thus, is not the size of its span nor the power of its circuits; it is the size of the dream and the depth of the commitment it represents," Quayle's letter said. European Space Agency (ESA) Director General Jean-Marie Luton sent Truly a letter that stated, "My assessment of the results of this activity, based on the available data and supported by the extensive participation of ESA staff in the exercise, is that they are acceptable to ESA." The Japanese Minister of State for Science and Technology Akiko Santo stated in a letter, "NASA's continued commitment to 75 kW and an eight man crew capability was confirmed, and the technical impact on the [Japanese Experiment Module] development remained minimum." Canadian Space Agency Director Larkin Kerwin told Truly, "From the Canadian perspective, we believe that the restructured program discussed by the parties at the Multi-lateral Program Coordination meeting on January 31, 1991, has addressed our concerns regarding the assembly and maintenance of the station. We strongly support proceeding with the restructured program ." Kerwin continued, space station "not only represents a substantial step forward in humanity's exploration and exploitation of space, but it is also a test of the ability of many countries to concert their efforts toward a common goal."