"6_10_8_21.TXT" (30411 bytes) was created on 06-09-92 STATION BREAK -- VOL. 4 NO. 6 JUNE 1992 HOUSE DEFEATS MEASURE TO KILL STATION FUNDING The House voted 254-159 last month to defeat an amendment that would have killed Space Station Freedom's fiscal year 1993 budget of $2.25 billion. The full House vote came after Rep. Tim Roemer, D-Ind., introduced an amendment to nix funding for Freedom from the overall NASA 1993 budget. Explaining his reason for introducing the amendment, Roemer said he thinks the $2.25 billion would be more wisely spent by adding $1.1 billion of those funds back into other NASA programs and putting the remainder toward reducing the deficit. The majority of representatives, however, voted to support the Freedom program and against the Roemer amendment. Rep. George Brown, D-Calif., said, "The gentleman from Indiana made some statement about the fact that later, in better times, we might come back and rebuild [the space station]. We might, but I can assure him that there will already be other space stations up there, and there will not be much impetus for the United States to put one up because Japan and Europe, either separately or together, along with the Russians, and perhaps other nations, will have their own space stations up there. The United States will forever have lost the image of being a world leader in space." Besides citing the loss of American leadership in space, Brown and Rep. Jim Sensenbrenner, R-Wis., said the United States must abide by its agreements with the station's international partners -- Japan, the European Space Agency and Canada. The European Space Agency already has spent $1.5 billion of its $4.5 billion commitment, for example. "This amendment breaks the word of the United States of America to the international partners who have committed literally billions of dollars to fund their share of the international Space Station Freedom. If we unilaterally pull the rug out from underneath the space station, their billions of dollars of investment, based upon their faith in America keeping its word, will go down the drain," Sensenbrenner said. "This is the fourth vote in the House on Space Station Freedom. I hope it is the last one, because if we make a decision, we ought to stick by that decision and go ahead," he added. Defending the scope of the space station's influence over technology advancement, Rep. Marilyn Lloyd, D-Tenn., said, "Space Station Freedom should be understood as a contributor to our economic future and our technology base. Incorporating the most advanced technologies and materials is the key to future stability of our economy. "The experimental platforms on Space Station Freedom provide the type of environment that is conducive to researching and producing materials that will advance our industrial base into the 21st century," she said. "Our space program is yielding a nine-to-one return on our investment." GOLDIN TOUTS STATION'S PURPOSE BEFORE HOUSE VOTE Editor's Note: This is an excerpt from NASA Administrator Daniel S. Goldin's speech to the American Institute for Aeronautics conference on April 28 in Washington, D.C. Our work on Space Station Freedom with Europe, Canada and Japan will open up a whole new world of cooperation. We can do more together with a shared vision than is possible acting alone. I soon intend to reach out to visit our partners in this great adventure and start a dialogue on how we can explore Earth, the solar system and the universe together. When we plan what NASA will do year-to-year, we need to consider where we want to be, not next year, but in 50 years, 100 years -- yes, even 500 years. I don't know about you, but in 500 years, I want one of my successors to be able to turn over the keys of a spacecraft to a Captain Kirk or Picard to go find out if anything is orbiting Alpha Centauri. To those who say Apollo was a one-shot deal, never to be repeated, that we've got problems to solve here on Earth, I say: Right now we risk making the same mistake as the Chinese emperors over 500 years ago. Some of you might know this story. Consumed by other priorities at home, they banned further exploration of Africa, made leaving the country a capital offense, and burned their fleet to ensure such "wasteful" exploring would never happen again. Instead of spreading its culture and influence, China turned inward, leaving the exploration of Africa and the Americas to Columbus and other Europeans. All this is my way of saying: we cannot pretend the decisions we make today don't have historic consequences for the future. July 20, 1989 was a historic day. For on that 20th anniversary of humanity's greatest accomplishment, President Bush said, "The Apollo astronauts left more than footprints on the moon; they left some unfinished business. America's ultimate goal was not to go there and go back, but to go there and go on." For the first time in decades, we are fortunate to have a president and vice president who personally support a vigorous space program . . . The primary purpose of Space Station Freedom is to be the premier outpost in humankind's efforts to learn how to live and work in space. The time our astronauts have spent in space is but a blink of an eye -- a tiny fraction of what we'll need to know to start a permanent presence off good old terra firma. How will the body take the stress of zero-G? Prolonged hazardous radiation? Long stretches of isolation in cramped quarters? How do we assemble hardware? Dock and rendezvous? And what about how dexterity will be affected after long periods of zero- or partial-G? Will astronauts have the strength and agility to respond in life-threatening situations when a rescue is required? All this must be learned before we can ever go back to the moon and go on to Mars. And the only place to learn is a space station. ASTRONAUTS WOW THE WORLD WITH SPACE WALKS NASA's Space Shuttle Endeavour crew captured the imaginations of millions worldwide during last month's unprecedented mission of firsts. This mission "brought the magic back to our space program," said NASA Administrator Daniel Goldin. "It represented the best in us all." It was Endeavour's maiden flight, the first time four space walks were performed on a single Shuttle mission, the first time three astronauts squeezed into a two-person airlock and then worked together to save a commercial satellite, and the largest (volume- wise) assembled fixture ever built in space. Not only did the successful capture, repair and then deployment of Intelsat's crippled 4 1/2 ton satellite mark a number of firsts, but the Space Station Freedom- related space walks will yield priceless space-based construction information, said Mike Hawes, manager, Utilization and Operations Office, at the Space Station Freedom Program Office in Reston, Va. One of the key elements of the evaluations was to quantify the logistics, workload and timing of specific assembly sequences. The demonstrations were slower than expected based on underwater training, pointing to a need for the evaluation of assembly concepts in orbit before Freedom construction begins, Hawes said. Known as the Assembly of Station by Extravehicular Activity Methods (ASEM), this 7 hour and 45-minute space walk, performed by mission specialists Kathy Thornton and Tom Akers, and the analysis following, will evaluate assembly and mass handling techniques proposed for space station assembly. The ASEM portion of this mission was shortened by a day because of the unexpected difficulty with capturing Intelsat. The ASEM hardware was designed and developed by McDonnell Douglas Space Station Division for NASA's Johnson Space Center in Houston. Thornton and Akers began their mission by completing construction of the ASEM truss, which was partially built the day before to support the Intelsat capture. The pyramid-style truss was built to emulate the station's pre-integrated hexagon-shaped truss. The two astronauts attempted to dock the simulated truss section to a pallet on the end of Endeavour's robot arm. This simulated the installation of crew module nodes to Freedom's truss structure. The crew also demonstrated one of the candidates for the space walker self- rescue equipment, known as the crew propulsive device. "Watching it on television, it seemed to go well. Tom Akers was able to translate himself and move around well," Hawes said. Lessons learned from these flight demonstrations, which were recorded on film and video tape, will help station engineers choreograph the best assembly techniques for Freedom. Engineers will scrutinize the film, collect feedback from the crew, as well as other data and then make specific recommendations from there, Hawes said. Besides the ASEM activities, which will teach designers a great deal, the Intelsat- capture and repair has provided a wealth of information, Hawes said. "We've learned so much about mass handling and the other Intelsat-related trials and tribulations that we'll be able to better prepare for, and hopefully avoid, these type problems," he said. During an interview on a Sunday morning talk show, Capt. Daniel Brandenstein, Endeavour's commander, said, "There are things we learned on this mission that we're going to bring back and wrap into the [Space Station Freedom] program relating to that environment." "Some of the big lessons we learned are that you have to move big masses very slowly and carefully; you have to have good handles on them so space walkers can get a good grip; you have to have good positioning for him or her, because you're not very mobile in the spacesuits, and you have to have good foot restraints so they can interact with their base, which, in this case, is the Shuttle. These are the types of things we are looking into." Brandenstein pointed out that the space station already is being designed as 'user-friendly'. "Interestingly enough," he said, "the truss is being designed so we don't have as much busy work, for lack of a better term. Engineers are designing a pre- integrated truss that will make our job much easier." SPACE STATION FREEDOM CHIEF SCIENTIST SPEAKS OUT Editor's note: This is a question and answer interview with Space Station Freedom's new chief scientist, Dr. Robert Phillips. Q: Now that you have been here for a few months, what do you, as chief scientist, perceive as Space Station Freedom's purpose? A: To me the primary purpose is to conduct science. In that regard, I find it difficult to separate science from technology. Whether the information comes from NASA's Office of Commercial Programs, the Office of Space Science and Applications, or the Office of Aeronautics and Space Technology, there will be a wealth of new knowledge that can be used by all realms of science and technology. It's hard to predict all the many benefits we will derive from research aboard Freedom; I don't think it's possible to pinpoint specific spinoffs. However, I know that all of science and humanity will benefit. At no time in history have we had this kind of an opportunity to learn, to study, to conduct research away from the Earth's surface. I see Space Station Freedom as the next logical platform in the continuing exploration of our solar system. We need to learn to live and work for long periods of time, continuously, before we can move to a lunar outpost and then on to Mars. We can't gain that kind of information from Space Shuttle flights alone, and there's not enough data from the Russians for us to come to any conclusions about how to live and work in space in a productive way. We have to find out how well we can survive on a long journey, how much work we can expect from a crew, as well as how they will fare when they return to Earth. Q: Speaking of a lunar exploration, why doesn't NASA just skip Space Station Freedom and build a colony on the moon? A: That is always an appealing idea, but to me, a major benefit of Space Station Freedom is the ability to study the effects that near-zero gravity has on organisms. It is fascinating that all organisms, from prokaryote bacteria which are the very simplest form of life, through all of the plants and animals that have been studied, react to the weightless environment. We have no idea how the apparent lack of gravity affects their chemical balances, their structure and behavior. To more directly answer your question, Freedom and its centrifuge facility will be able to provide our first experience in studying the effect of moon-simulated gravity on plants, and animals, including mammals. It seems to me that knowledge of chronic effects of that type will be invaluable to moon colony planners when they begin to consider placing humans on the moon for long stays in a colony type situation. Q: What do you see as your role as chief scientist? A: I want to enhance the perception, to the broad scientific/engineering community and the lay public, that Space Station Freedom will do good, solid science. From my point of view, any science done well will benefit humanity. It is my firm personal belief that all good science, no matter what discipline, will benefit all. Although my training is as a life scientist and a veterinarian, I am, for example enriched by planetary exploration and astronomical observations. In turn, those physical scientists will benefit from what we learn about life processes aboard Freedom. In my view, that philosophy cuts across the entire spectrum of science, engineering and technology. Q: Which fields of science will benefit from Space Station Freedom? A: Materials science, life science, as well as the planetary sciences will benefit from research aboard the space station. We now have four external ports for scientists to attach payloads to the station's truss outside of the pressurized volume. This will greatly expand our ability to conduct a variety of experiments related to the low Earth orbit environment. Microgravity scientists and life scientists will benefit because they will have longer periods of time to conduct experiments. For example, microgravity scientists will be able to study protein crystal growth to better understand their structure, and life scientists will be able to grow plants from seed to seed -- to study biological development. On Freedom there will be more power and more rack space available to researchers than ever before; this will greatly increase the flexibility and productivity of the station. Q: Is the process of getting a payload aboard Space Station Freedom too bureaucratic and too cumbersome for non-NASA payload investigators to use? A: NASA is working hard to facilitate ease of an investigator's integration into the system and through the process, so that science will be easy to accomplish. Since coming on board I have been closely involved with the Customer Support Team from the Office of Space Flight. Speed of integration and ease of access is a paramount concern of this group; we want to make flying an experiment on Freedom a productive and positive experience. Q: Why are there several science communities fighting Space Station Freedom funding? A: I think people in those communities don't realize what they will gain individually and collectively from the kind of science that will be done on Space Station Freedom. One of my responsibilities as chief scientist is to act as an information source to the science community as a whole and particularly to those societies who have a negative outlook or are operating from an uninformed basis. We want to educate and inform them about about our goals and aspirations and how they will benefit from this new knowledge that will be acquired. I have already spoken to several groups and individuals who have concerns. I am eager to talk to organizations and societies who have questions about the space station and its benefits. I will speak to any group, society or organization who would like to know more, so that they can come to an informed decision about potential benefits from the science and technology that will result from the operation of Space Station Freedom. Q: Why is the centrifuge facility important to the program? A: The centrifuge, which under the current plan will be delivered on the next flight after Freedom reaches permanent occupancy, is essential for life sciences research for a number of reasons. It will provide a one-G control but, equally important, it will help us begin to study fractions of gravity, such as 1/6-G that we find on our moon. There is no way to duplicate that opportunity here on Earth. We need to understand how the forces of gravity affect both plant and animal organisms. Are there gravity thresholds, or is response to gravity a continuum? We already know we have a problem nurturing plants to maturity in near-zero G gravity, but we don't know what fraction of gravity will help plants orient their roots to grow down or allow them to develop seeds. In space it has been difficult to study plant development from seed to seed to seed, which is what life scientists want to do. You can't do much of that on a 13-day Spacelab flight. The idea of studying fractions of gravity is important for the Lunar-Mars mission. The centrifuge will accommodate habitats for plants, animals, and have special containers for cell cultures and developmental biology. It will be the cornerstone of gravitational biology research. Q: You've spoken a great deal about life sciences, what about the other disciplines? A: Although I've talked a lot about life sciences because that is my background, I am a representative of all the science disciplines for Space Station Freedom. Materials and microgravity sciences, the environment of low Earth orbit, observational sciences to the extent that they can be incorporated, development of new technologies, commercial applications as well as life sciences are equally important to the success of the station and our understanding of how to improve life here on Earth. Q: What must the program do to ensure good science? A: Well, the first thing is to recruit good scientists and to involve young people. We need to involve people with vision; people who can see the unique possibilities of doing research in space. I believe, from what I've seen in the microgravity and life sciences divisions, that we are on the road to developing good generic equipment that will allow a variety of science opportunities aboard the station with minimal requirements for the development of specialized extra equipment. Certainly some experiment-unique equipment will be necessary, but the basic facilities will be there. We are not quite ready to recruit the individual investigators who will do the first experiments, but that time is rapidly approaching. My greatest concern remains crew time and the availability of the crew to conduct experiments. For example, on Spacelab there is usually a payload crew of four working with eight double user racks. On Space Station Freedom there will be 44 double payload racks with a payload crew of two to tend to science research. There's no way those two crew members can be experts on all the varying experiments that will fly on the space station to the same degree that they would be on a Spacelab flight. Because of this, it simply will take longer to do some of the experiments, and some of the experiments will have to be less complex from an operator's standpoint. On the flip side however, we will be gaining far more data than ever before, and we will be keeping more scientists on the ground busy analyzing that information than ever before. It just means that we must learn to modify our approach to designing equipment, as well as organizing operations and the timeline. FREEDOM ON THE RIGHT TRACK FOR SCIENCE A group of experts representing the Space Station Freedom science user community recently gave the Freedom program a stamp of approval. After many months of studying NASA's plans for accommodating space science research on Freedom and questioning agency officials regarding a range of issues and concerns, the Space Station Science and Applications Advisory Subcommittee (SSSAAS) concluded that the facility will be well-suited for scientific research. The SSSAAS, a subcommittee of the NASA Advisory Council's Space Science and Applications Advisory Committee, devoted many hours to exploring the suitability of the station's design for scientific research. The subcommittee was created five years ago to ensure that Freedom science users could evaluate and respond to NASA's requirements for using Freedom, and that NASA would respond to the science community's space research needs. In addition, the SSSAAS coordinates communications between its parent committee and the Space Station Advisory Committee and maintains an active liaison with the scientific advisory committees of NASA's international partners (Canada, Japan and the European Space Agency). During its February meeting in Sunnyvale, Calif., the SSSAAS made clear its position that Space Station Freedom provides a unique and essential environment for the accomplishment of science. The Space Station Freedom program is taking positive steps to maintain and improve the scientific potential of the on-orbit facility, the committee said. The SSSAAS recognizes that significant potential exists in the current space station program for advances in scientific and technological research, particularly in the materials, fluids, combustion and life sciences. In previous discussions, the SSSAAS has identified additional activities or resources required to correct deficiencies or incompatibilities in designs or plans. Space Station Freedom program officials were attentive to concerns expressed by the SSSAAS. Presentations and discussions at the latest meeting of the subcommittee affirmed or clarified Freedom's capabilities to support productive utilization in a number of areas. The SSSAAS acknowledged, for example, that NASA has made progress toward implementing the capability to monitor and control perturbations in the microgravity environment that is so critical to science users. Integration of the centerpiece of on-orbit life sciences research --- the 2.5 meter centrifuge facility, including its animal/plant habitat systems and life sciences glovebox --- is now part of the baseline for the first phase of the space station program. Plans are being made to monitor and manage natural and induced contamination in Freedom's external environment. NASA also made substantial progress in addressing user requirements for end-to-end data services. Finally, the space station program was applauded for restoring a modest capability to support experiments mounted on the external truss. The February meeting marked an important transition for the space station science subcommittee. Dr. Charles A. Fuller, professor of physiology at the University of California, Davis, took over as chairman of the subcommittee from microgravity scientist Dr. Robert J. Bayuzick of Vanderbilt University. NASA DEVELOPS REVOLUTIONARY ROBOT 'SENSING-SKIN' A team of robotic engineers at Goddard Space Flight Center in Maryland have developed a revolutionary proximity sensor. The new sensor relies on an electric field to detect objects within a range of just over one foot. It can be built to be completely flat (less than one-tenth of an inch thick) and is extremely rugged. This simplifies the application of the sensor to robot arms, spacecraft or payload surfaces. Here is a scenario of how it would be used: Sitting in the cupola, a Space Station Freedom crewmember prepares for a routine inspection of Freedom's external structure. The cupola commands a sweeping view of the port-side truss structure that stretches out to the solar arrays slowly rotating to keep pace with the sun. The crewmember's attention is focused on Freedom's telerobot, the Special Purpose Dexterous Manipulator, already in position to help inspect the truss. To perform the inspection, the crewmember must maneuver a video camera, held at the end of the dexterous telerobotic manipulator, in and about the truss section. The dexterous manipulator is a series of arm segments and joints, elbows as it were, that provide the compound motions needed to perform such tasks. Guiding the telerobot's arm from the cupola is a demanding skill requiring concentration to avoid bumping surrounding structure and mechanisms with the robot's elbows and arm segments. This new sensor technology, however, promises to make the crewmember's task much easier. It will enable the crewmember to quickly and confidently maneuver the robot arm and camera in and out of tight corners without bumping into surrounding objects. Avoiding collisions is an everyday part of life. People avoid bumping into others, change lanes on the highway, and duck under low ceilings. Success at avoiding collisions is directly related to the sensory input available to people through sight, sound and touch. Our eyes, ears and skin are our primary collision-avoidance sensors. When people build machines, such as robots, to move about and interact with their surrounding world, robots also must have the sensors needed to interact with that world. Space Station Freedom relies heavily on the use of telerobotics, that is, robotic devices under the control or supervision of a human operator. Robots provide astronauts with extended reach, magnified strength and, through the use of cameras and other sensors, a virtual presence at the robot's location. While the robot augments the capabilities of the human operator, the operator provides sensory and high-level decision making capabilities for the robot. A major concern for the human operator in any teleoperated system is the avoidance of collisions between the robot and its environment. To prevent collisions, the operator is given as much information about the work site as possible, including data from other vision and force sensors. Neither of these sensory modes can be used to guarantee safe and collision-free motion. Visual data, although essential, is not always able to supply the operator with the right warning of an impending collision. This can happen because of awkward viewing angles, inadequate lighting or obstructed views. Moreover, indications from a force sensor serve merely to indicate that potentially harmful contact has already taken place. There are other approaches to help robots move about. For example, one common method is to develop a mathematical computer model of the robot and the world around it. This world model defines the position and orientation of everything in the relevant environment, and keeps track of the robot's location and position in that world. Also, the accuracy with which objects are defined in the mathematical model is fixed, whether the task being worked on requires coarse or fine determination of relative positions. The model does not provide the operator with more accuracy as the delicacy of a task increases. A large detailed world model, as is required for Freedom, greatly increases computational requirements. Thus, this approach can significantly slow down telerobotic operations in complex situations. To address these limitations, the Goddard Space Technology Division's Robotic Branch developed the new proximity sensor. This sensor is the product of an in-house development effort, with support from the Space Station Level I Engineering Prototype Development activity. The sensor uses a unique capacitive reflector (capaciflector) technique to enable simple electronic elements to detect approaching objects with unprecedented range, sensitivity and resolution, despite being mounted against electrically grounded payloads and robot arms. The approach is an extension of a technique used in instrumentation systems to eliminate stray capacitance. As an object comes closer, the capacitive coupling between the sensor and the object increases, resulting in increased sensitivity for accurate sensing at very small distances (0.030 inches at 0.5 inch range). By assembling an array of sensors, a 'sensor skin' can be created to provide both robot arms and payloads with an unbroken, early-warning protective field so collisions will be avoided despite obstructed views or unanticipated events. Since the resolution of the system grows more accurate at increasingly closer ranges, it can provide precise, sensory-interactive guidance and alignment for tasks such as docking and berthing payloads. The operator is able to guide the overall direction of the task knowing that obstacle avoidance is being supported automatically. The system can be thought of as electric 'cat whiskers' that permit the robot to feel its way around obstacles. It is simple, robust, and works on a wide variety of materials, including humans. This system has been routinely demonstrated to perform collision avoidance at ranges in excess of one foot. In addition, orbital replacement unit mock-ups have been instrumented with these sensors and each precisely guided into its mating interface. The sensor system shown here is essentially space qualifiable. The materials and electronic components are either Mil-spec or made of materials that have flown in space. The sensors 'see' through flight paint and even the stickers that are placed on flight hardware. The system has been inspected by safety, thermal and electromagnetic interference engineers to ensure its suitability for long-term space operations. Important technical advances continue to be made in the sensor's development. The capability to construct three-dimensional terrain models of objects in the near field (one-inch range) has been demonstrated and an electrically scanned array is in development. This will further facilitate precision docking, berthing and robot control; even precontact 'virtual' forces can be created to aid the human operator. By making the telerobot 'smart' about its short-range environment, the capaciflector sensor skin, coupled with the robot's control software, can relax the burden on the operator while improving the speed, safety and utility of telerobotic operations. The materials and electronic components are either Mil-spec or made of materials that have flown in space.