MIT Reports to the President 1998-99

DEPARTMENT OF AERONAUTICS AND ASTRONAUTICS

The academic year 1998—99 was a year of explosive activity for the department. We began the full-scale implementation of our 1997 strategic plan. The plan was a reaffirmation of our focus on the intellectually and industrially robust field of aerospace, coupled with a commitment to redirect the intellectual basis of the Department to set and serve the directions of this industry. The new vision of the department which emerges is one which stands on three broad disciplinary bases: the traditional engine and airframe disciplines; the disciplines of real time system critical aerospace information engineering; and the disciplines required to architect and engineer extremely complex systems.

During AY 1998—99, we launched a reform of our educational programs intellect to make the conception, design, implementation and operation of systems the engineering context of our education. This involved the design of our new Learning Lab for Complex Systems, and a number of educational development efforts. Other Implementation teams focused on education, research, and our System Architecture and Engineering thrust.

During the year, we were joined by a number of new faculty, including Professor Vincent Chan in communications, Nancy Leveson in software, Brian Williams in autonomy, Eytan Modiano in communications and networking. Professor Daniel Hastings returned form his leave as the Chief Scientist of the Air Force. Student enrollment at both the undergraduate and graduate level was on an upswing, and once again research activities increased markedly.

A total of 273 applications were received for the Fall, 1999 term. Out of this, 144 were admitted and 77 accepted the offer of admission. Enrollment for Fall, 1998 included 127 S.M., 63 Doctoral, 2 EAA, and 9 MEng degree candidates for a total of 197. Total minority students: eight (2 Doctoral, 6 S.M.). Total women students: 31 (5 Doctoral, 25 S.M., 1 MEng.). In the Spring, 1999 term we received 20 applications. We admitted nine and three enrolled. Three women applied, but none were admitted. Zero minority applications were received. Enrollment for Spring, 1999 included 107 S.M., 60 Doctoral, 2 EAA, and 10 M.Eng. for a total of 179. The total number of women students is 28 (4 Doctoral, 23 S.M.,1 M.Eng.). The total number of minority students is 7 (1 Doctoral, 6 S.M.).

Dr. Richard H. Battin, Senior Lecturer, received an Honorary Doctor of Science degree from Texas A&M University on May 14, 1999 for his pioneering work in celestial navigation and orbital mechanics.

Professor John-Paul B. Clarke has been awarded the 1999 J. Hollingsworth Speas Award for his contribution toward achieving compatible relationships between airports and/or heliports and adjacent environments. Clarke is the Charles Stark Draper Assistant Professor of Aeronautics and Astronautics at Massachusetts Institute of Technology in Cambridge, Massachusetts.

His research and teaching focus primarily on the environmental impact of aviation; the application of advanced technology to aircraft operations and air traffic control; and the modeling, design, and operation of complex systems.

Clarke developed NOISIM, a system analysis tool that combines a Flight Simulator, Noise Model, and Geographic Information System (GIS) to create a unique rapid prototyping environment in which the user can simulate an aircraft's operation in existing and potential guidance and navigation environment's, while simultaneously evaluating the aircraft's noise impact. He demonstrated the benefits of reduced thrust approaches as a means of providing significant noise reduction in communities surrounding airports, and the fact that advances in air traffic control capabilities now enable implementation of these procedures. The results of his work were published at the AIAA Aerospace Sciences and Acoustics conferences, and are now in review for the AIAA Journal of Aircraft.

The Jay Hollingsworth Speas Airport Award is co-sponsored by American Institute of Aeronautics and Astronautics (AIAA), the American Association of Airport Executives (AAAE), and Airport Consultants Council (ACC) and was established in 1983 to recognize distinguished contributions to the field.

The award was established on a grant from the Planning Research Corporation.

Mr. Speas was vitally interested in improving environmental relationships between the airports and the communities they serve. He accomplished a substantial number of professional assignments that contributed to improvements in these relationships, both civil and military.

Professor Dan Frey won the Everett Moore Baker Award for outstanding undergraduate teaching at MIT.

Professor R. John Hansman won the 1998 Bose Teaching Award for the School of Engineering.

Professor Paul Lagace was appointed Co-Director of the Leaders for Manufacturing and Systems Design and Management's Programs.

Professor Earll Murman has won the Department Undergraduate Teaching Award.

Professor Dava Newman was profiled in the National Academy of Engineering, Women Engineers Gallery Profile. Professor Newman is an AIAA Distinguished Lecturer and has become a Taplin Faculty Fellow in Health Sciences and Technology for 1999—2000.

Dr. Robert C. Seamans, Jr. received the Wernher von Braun Memorial Award from the National Space Society May 1999.

Professor S. Mark Spearing has received the department's advising award in May 1999.

The Massachusetts Space Grant Consortium now includes MIT (Lead), Tufts University, Wellesley College, Harvard University, Boston University, University of Massachusetts, Worcester Polytechnic Institute, Marine Biological Laboratory, Five College Astronomy Department, Boston Museum of Science, and the Charles Stark Draper Laboratory. The Wright Center at Tufts is responsible for education of pre-college teachers in space science and engineering, through summer workshops. The Program continues to support undergraduate research through the MIT Undergraduate Research Opportunities Program. It increased the number of companies involved in placing students for summer employment in the aerospace industry, supported students for the summer at the NASA Space Academy, supported two high school students at the Advanced Space Academy, and offered graduate fellowships. It sponsored a popular undergraduate seminar subject on "Modern Space Science and Engineering" with emphasis this year on humans in space with guest speakers from our industrial affiliates, and academic affiliates. The annual public lecture this year was given by Dr. Peter Glaser, Vice President, (Retired), Arthur D. Little, Inc. The emphasis of the fifth annual space forum was on the International Space Station. Dr. Kathryn Clark, Chief Scientist of the Space Station, was the luncheon speaker.

The Active Materials and Structures Laboratory (AMSL) focuses on the development of innovative technologies for active control of aerospace systems. Research has covered a broad range of disciplines including materials science, structural mechanics, structural dynamics, control, and solid-state actuation systems. The laboratory has coordinated multidisciplinary research programs ranging from fundamental materials microstructure investigations to helicopter control systems feasibility studies. Major research thrusts in 1998—1999 were: further development of the ONR-funded program on micro-hydraulic solid-state transducers and the DARPA-funded program on micro solid-state energy harvesting mechanisms; development of new micro-machining processes for fabricating silicon carbide components; development of new active material compositions, single crystal ceramics, synthesis techniques and material models for active ceramic materials suitable for high actuation and sensing functions, and further work on the development of distributed structural acoustic control techniques. Fundamental research was motivated by a variety of ongoing applications programs. AMSL, a member of the Smart Structures Rotorcraft Consortium with Boeing and McDonnell Douglas, has continued to work on developing actively controlled helicopter rotor blades for vibration and noise reduction. Also as a member of the Active Fiber Consortium together with Continuum Control Corp., CeraNova Corp., ACX Inc., Boeing, and the Naval Undersea Warfare Center, AMSL has further improved the modeling and manufacturing techniques of active fiber composites. The laboratory also continued to advance applications projects in the active Control of structural acoustics: active vibration control of torpedo radiated noise, far-field radiated sound from panels and cylinders, as well as control of interior noise in aircraft. The laboratory facilities available were: active material and device characterization; static and dynamic structural testing; structural acoustic testing; hover test stand, and real time control hardware.

The Fluid Dynamics Research Laboratory (FDRL) is active in research concerning computational, analytical and experimental issues in fluid dynamics and aerodynamics. Current research projects include: the development of a "distributed flow simulation environment" capability; aerodynamics of subsonic, transonic, and hypersonic vehicles; aeroelasticity; methods for developing low order aerodynamic models for multidisciplinary analysis; computational and experimental approaches to active flow control; the development of tools for aerodynamic analysis and design; distributed visualization; development of distributed fast equation solvers; and development of algorithms for assessing and quantifying numerical uncertainty.

The Gas Turbine Laboratory is an intellectual community of about 80 people, including 8 faculty and over 50 graduate students focussed on the problems of air-breathing propulsion and energy conversion. Highlights for AY 1998—99 include the following.

The "micro engines" (shirt button sized gas turbine and rocket engines) project has expanded to include about 50 faculty, staff, and students from three departments representing a diverse set of engineering disciplines. This multidisciplinary project is device oriented and has the aim of producing MEMS (Micro-Electro-Mechanical-Systems produced with integrated circuit manufacturing techniques) based gas turbine engines for power production and airplane propulsion, micro compressors for analytical instruments, and rocket engines for spacecraft and micro-launch vehicles. Achievements during the past year include operation of a micro turbine at speed of more than 1.2 million rpm.

Professors Jack Kerrebrock and Mark Drela have demonstrated that their new approach to compressor design, aspirated compressors, can double the amount work than can be achieved with a single compressor stage. The implications of this include significantly shorter, lighter, quieter, more efficient gas turbine engines.

Professor Jack Kerrebrock and a former student have one a best paper award from the American Society of Mechanical Engineers International Gas Turbine Institute. This is the eighth award the Laboratory has won from the ASME since 1990. Professor Epstein was elected to the National Academy of Engineering.

The objective of the International Center for Air Transportation is to improve the safety, efficiency, and capacity of domestic and international air transportation and its infrastructure, utilizing information technology and systems analysis. The principle new thrusts of ICAT over the past several years have been in advanced Air Traffic Management, understanding airline industry dynamics and in mitigating adverse environmental effects. The activities in this area have ranged from evaluations of future operational concepts for the US National Airspace System; preliminary design of decision aids to improve airport departure rates; development of conflict and collision alerting; evaluation of Collaborative Decision Making between ATC and airlines; evaluation of analytical models of ATM systems and conducting fundamental human performance studies of pilot and controller interactions. ICAT has continued to work in the areas of cognitive systems and decision aids for flight critical cockpit systems. This work includes advanced alerting systems, human understanding of advanced flight automation systems, and other flight safety topics. ICAT has also developed and flight-tested a single antenna GPS attitude determination system.

The Lean Aerospace Initiative (LAI), begun in September 1993, is an active research partnership among 15 aerospace companies with organizational units, 14 U.S. Government agencies, labor representatives, and MIT. LAI also collaborates internationally with the University of Linking and the UK LAI.

Over the past six years, LAI's goal has been "To significantly reduce the cost and cycle time for military aerospace products throughout the entire value chain while continuing to improve product performance." LAI research is being conducted by over a dozen faculty members from the Schools of Engineering and Management, 21 graduate students from several MIT courses and Graduate programs, and five research staff members of the Center for Technology, Policy, and Industrial Development. The Co-Directors of LAI are Prof. Earll M. Murman, Prof. Tom Allen, and Mr. Cliff Harris.

To date, LAI has generated a significant body of knowledge about lean practices in an industry undergoing a fundamental, systemic transition. Research studies and results include: a supply chain framework for strategic supply chain management; early supplier integration into design and development; product development value stream framework; tools for risk and variability management; inventory practices; and flow optimization.

LAI also provides a new model for industry/government/labor/academic collaboration. This model has been supported by: The Lean Enterprise Model; recommendations on policy; six implementation workshops; 16 Air Force supported pilot projects; 12 plenary workshops; reports, briefings, and articles.

Most recently, LAI announced plans for a Phase III beginning September 1, 1999 which would propel the initiative in expanded directions focused on "Best Life Cycle Value" and barriers to implementation & transition to lean. Future goals include enhancing effectiveness of the national workforce and emphasizing knowledge deployment.

Further information on LAI can be found on the World Wide Web at http://web.mit.edu/lean/.

The Lean Sustainment Initiative (LSI) is one of several MIT research programs focused on enhancing the performance of complex enterprises. In its third year, the LSI is based on many of the lessons learned in the International Motor Vehicle Program (IMVP) and the Lean Aerospace Initiative (LAI). LSI's goal is to increase the flexibility and responsiveness of the Air Force sustainment enterprise while simultaneously reducing its cost. LSI is a joint project of Headquarters Air Force Material Command, Air Force ManTech, and MIT. Faculty, research staff, and graduate students from the School of Engineering and the Sloan School of Management form the LSI core research team.

The U.S. military today has fewer resources for logistics support. Consequently, current sustainment operations-maintenance, repair, and overhaul-require systemic change. LSI is undertaking the research that the Air Force combat support community needs to initiate fundamental, systemic change.

The LSI research team has established a baseline understanding of the Air Force sustainment system and produced several case studies, executive summaries, and graduate theses. Current program objectives are to facilitate the collaborative process to increase the involvement of government and non-government sustainment stakeholders, develop specific long-term research areas, and to begin the process of assisting the Air Force to develop a 21st century high-value sustainment enterprise.

The Space Shuttle STS-90 Flight of Neurolab included an experiment on the role of visual cues in spatial orientation, designed by a team of US and Canadian investigators led by Dr. Charles M. Oman. Results presented at a symposium at the National Academy of Sciences in April showed dramatic changes in motion, orientation, figure recognition, and shading interpretation occurring during a two-week microgravity exposure. The STS-95 flight of Sen. John Glenn included the most recent utilization of "PI in a Box", the on-board expert system designed by Prof. Young to assist astronauts in the conduct of a sleep experiment conducted by Prof. C. Czeisler of Harvard Medical School. The data analysis of the Enhanced Dynamic Load Sensors (EDLS) Experiment has been completed and produced the first quantification of astronaut-induced disturbances to the microgravity environment during long-duration space missions. The results are being incorporated into structural models for the International Space Station (ISS) by NASA and its contractors. Results indicate that microgravity disturbances on ISS will be less than previously thought. The design and development of advanced force and moment sensors to aid astronauts on ISS and support researchers is being continued. This effort, known as MICR0-G Project, is conducted jointly with the Politecnico di Milano University in Italy. Using a commercial off-the-shelf development platform, the electronics component of the sensors has been reduced significantly in mass and volume. (Prof. D. Newman) Experiments are being prepared for the International Space Station. These include the MICRO-G project and VOILA, an experiment on spatial orientation and visuomotor coordination performed by a US-Canadian-French-Italian team of investigators, led by Dr. Oman.

Meanwhile, ground based research continues. An anthropomorphic robot, on loan from NASA, is being modified by Dr. Newman for testing the ISS space suit and improving future space suit designs. Space suit testing of the current NASA EMU will begin this year with the human-sized anthopmorphic robot in the MVL. Results will lead to recommendations for future planetary space suits (i.e., Mars). Dr. Oman's experiments on human spatial orientation, navigation and 3D spatial memory in real and virtual environments continue, as well as a new project on advanced displays and controls for virtual reality systems. Collaborative experiments are also underway with Prof. Taube of Dartmouth to quantify the behavior of head direction cells in parabolic flight. An FAA flight and simulator research on cockpit displays for vertical navigation has been conducted, in collaboration with the Volpe Research Center.

MIT is one of the seven institutions in NASA's new National Space Biomedical Research Institute, headquartered at Baylor College of Medicine. Professor Larry Young of MIT is NSBRI's first Director. Dr. Charles Oman (XVI/CSR) and Professor Richard Cohen (VI/HST) lead NSBRI's multi-investigator, multi-institutional Neurovestibular and Cardiovascular research programs, respectively. Professor Newman is collaborating in a bone structural modeling project. NSBRI supports a total of five new MVL research projects. Education and outreach efforts include a Freshman Seminar offered during the fall term of 1998 focusing on the case for human planetary exploration (Prof. Newman and Dr. Oman) and the development of a space biomedical engineering graduate course, which is a collaboration between all seven NSBRI institutions, under Prof. Newman's leadership.

The Space Propulsion And Power Laboratory (SPPL) is a part of the Space Systems Laboratory (SSL), which focuses on the interactive problems related to the propulsive and power generating systems of spacecraft. The propulsive activity has dominated recently, and has continued to center on various aspects of Electric Propulsion and its mission applications.

Work initiated earlier has continued on a miniaturized 50 watt power version of a Hall effect thruster (V. Khayms, doctoral candidate). Tests have been performed at the ASTROVAC facility, using our small thrust balance, as well as at the AF facilities at Edwards AFB, California. Results are encouraging, but the very small dimensions and thrust level have made it difficult to obtain reliable performance figures. A new build is now available, and a new test series is planned at the Princeton U. facilities.

We have extended our existing numerical simulation model of the plume of Hall thrusters, to include effects of material sputtered from the walls of test tanks and from plume shields mounted on spacecraft (B. Asare, M.S. Thesis, Sep 1999). Further developments will be pursued under a new M.S. candidate, M. Brenizer. This code, plus that developed earlier for Hall thruster performance by J.M. Fife (Ph.D., 1998) are now in use at several major US aerospace companies.

A new and more advanced simulation code for Hall thrusters, in which electrons as well as heavy particles are treated as dynamic entities and moved in accordance to self-consistent electric fields is being readied by J. Szabo (Ph. D. candidate). This will shed light on ionization, electron transport, and wall-plasma effects in these devices.

Work has continued on alkali-seeded arcjets (D. K. Robertson, Ph. D. candidate). Since simulation results are positive, we are planning joint experiments on the concept with NASA JPL.

Doctoral candidate T. Onishi has continued developing a numerical code to compute the performance of bare metallic tethers as electron collectors in space. This bare tether concept, originated at our laboratory, is being implemented as the basis for ProSeds, a flight mission in preparation by NASA Marshall SFC.

As a result of our scaling studies of electric propulsion, we have advocated a revival of colloidal propulsion technology for use in micro-spacecraft, and have formed an informal alliance with industry (Busek Co.) and Yale U. for this purpose. The initial results of our studies (sponsored by AFOSR, NASA, and Draper Labs) show this to be a very promising micro-propulsion avenue for the future. Several graduate students are now engaged in this work: V. Khayms, Ph. candidate, (emitter theory); P. Lozano, Ph. D. candidate (emitter theory and experiments); M. Paine, M.S. candidate, (microfabrication); P. Reichbach, M.S. candidate (thruster controls). A joint proposal of our group resulted in selection of our colloid concept as the propulsive technology for one of the NASA JPL spacecraft contending for designation for the ST-5 New Millennium mission. This spacecraft was not selected for ST-5, but will contend again for ST-6.

Funding was obtained from the Defense University Research Instrumentation Program (DURIP) for the establishment of a Micro-Propulsion Laboratory), to be housed in the 4^th floor of Bldg. 37. A new cryo-pumped vacuum facility is in final design, as well as a microbalance sensitive to one micro-Newton thrust levels. Other equipment will include a custom-designed mass spectrometer for colloidal studies.

The hunt for Earth-like planets orbiting other is one of the primary objectives of NASA's Origins Program, which will launch a number of space-based observatories, starting early in the next decade. Due to the size constraints imposed by the payload bay of carrier spacecraft, these telescopes will undoubtedly require some form of on-orbit deployment mechanism, including joints or hinges which will introduce non-linearity to the structure. The success of the Origins missions will hinge on whether positioning of the optical elements can be maintained to within fractions of the viewing wavelength. Consequently, any minute disturbance will pose a serious threat to the stability of the precision optical systems. Acquiring a better understanding of the effects of damping and structural nonlinearities on the submicron-level dynamics is therefore essential to the telescope design.

The overall objective of the research program was to perform an experimental and analytical investigation of the microdynamics of deployable truss structures. Specifically, the main goal was to characterize the dynamic response of such nonlinear structures at sub-microstrain levels of mechanical and thermal excitation. In the case of mechanical excitation, the response was characterized in terms of modal parameters (the natural frequency and damping ratio). The response to thermal excitation was characterized in the time and frequency domains. This investigation of thermally-induced transient disturbances was performed at facilities made available by the MIT Lincoln Laboratory and Payload Systems, Inc. Furthermore, in the context of this research program, the Space Systems Laboratory collaborated with the NASA Jet Propulsion Laboratory on the IPEX (Interferometry Program EXperiment) space flight experiment, which flew on Shuttle missions STS-80 and STS-85. The SSL performed on-orbit flight data analysis, which resulted in the identification and characterization of on-orbit transient events associated with thermally-induced structural disturbances.

The goal of the program in Distributed Satellite Systems (DSS) is to identify the functions within spacecraft and between spacecraft that can benefit from distribution. Over the past several decades, the computer industry has evolved from using large, expensive mainframes for solving computationally intensive problems to using smaller, cheaper, more adaptable distributed sets of workstations collaborating to solve equivalent sized problems. Likewise, DSS will demonstrate how distributed arrays of smaller, cheaper spacecraft can achieve the same missions as current larger, more expensive, monolithic spacecraft with improved performance at lower cost.

To achieve this goal, the DSS program employs systems analysis concurrently with experimental work. First, U.S. Air Force space missions were classified according to how much they might benefit from distribution, and metrics for evaluating DSS designs were developed. Next, a testbed was built for experimental work. The testbed demonstrates the capability to perform acoustic interferometry via a distributed system of "satellites" (microphones). This testbed allows for the testing of different maneuvering profiles and collaborative algorithms. On the software side, a Generalized Information Network Analysis (GINA) simulation code was created in the spring of 1999 for the NASA Origins Terrestrial Planet Finder (TPF) mission. This code, which allows for the generation and comparison of many different system architectures during the conceptual design stage, has created a lot of interest in both government and industry circles. Future milestones include developing a similar software tool for the Air Force TechSat21 mission as well as a possible space flight experiment.

The MIT Space Systems Lab (SSL) is teamed with Air Force Phillips Lab and McDonnell Douglas Aerospace on the Theoretical and Experimental Studies of Vibro-Acoustic Systems (TESVAS). The goal of the project is to reduce the acoustic loads on spacecraft during launch by controlling the transmission and reflection of sound through the payload fairing. If successful, this research could significantly reduce the loads that account for more than 40% of first-day spacecraft failures.

An impedance matching control method has been developed for this project. This method is unique in that it only requires knowledge of the fairing structure and local acoustic coupling. In addition, sensors are only required on the fairing, not on the payload where they may interfere with deployment or performance. This method has been validated through experiments in an acoustic test chamber. Also, a sensuator (simultaneous sensor and actuator) has been studied, as a possible configuration of the sensors and actuators needed for this project, although with limited results. Currently, research at MIT is focused on extending the impedance matching concept to an acoustic power diode that will allow the flow of vibro-acoustic energy in only one direction.

The MIT Space Systems Laboratory has designed and constructed a testbed whose structural dynamic response is similar to that of proposed next generation space telescopes: the Space Interferometry Mission (SIM) and the Next Generation Space Telescope (NGST). The research goal is to address challenges faced by NASA's Origins

Program telescopes in areas related to dynamics and control, and to ensure that the results are applicable to these missions.

The testbed is designed to be as satellite-like as possible, and is neutrally stable at its axis of rotation to enable a one-axis slew maneuver. A reaction wheel assembly mounted at the bottom of the spacecraft bus section is used to slew the testbed. Disturbances traceable to those anticipated for the next generation space telescopes are engendered by the reaction wheels. The testbed's performance is measured with an optical system, which simulates the optical train of the space telescopes.

The precision space telescope testbed provides a platform for validating theory and techniques developed by the Space Systems Laboratory's Dynamics and Control Analyses of Space-based Interferometers research effort. Telescope slew control, and fine optical control and novel controller tuning techniques have been implemented on the testbed.

Future Space-based telescopes will provide the means for significant advances in astronomy. To ensure that stringent performance and stability requirements are satisfied, future structurally connected space borne telescopes will rely heavily on modeling and analysis efforts conducted during early design phases. Work is underway to support the Jet Propulsion Laboratory (JPL) in developing modeling and analysis tools that can be applied to the proposed Space Interferometry Mission (SIM) and validated on the JPL Micro-Precision Interferometer (MPI) testbed and on the MIT Precision Space Telescope testbed. Parallel work is underway to support NASA's Goddard Space Flight Center in the development of the Next Generation Space Telescope. Specific areas of work include: developing a reaction wheel disturbance modeling toolbox; developing a disturbance, sensitivity, and uncertainty analysis toolbox; developing a system optimization and design toolbox; organizing complex, integrated models; creating uncertainty models from experimental data and finite element models; developing a sensor and actuator selection and placement framework; and synthesizing and tuning active controllers.

The Middeck Active Control Experiment II (MACE-II), is a re-flight of the Middeck Active Control Experiment (MACE) that flew on the Space Shuttle (STS-67) in March 1995. The original MACE experiment was designed to investigate the modeling and control issues associated with the change in environment of a flexible spacecraft from systems-level functional testing in 1-g to operation in 0-g.

MIT/MACE-II extends on the linear modeling and control design of MACE to focus on the modeling and control of Time-Varying (TV) systems. The modeling approach from the original MACE flight is extended to the geometrically nonlinear system of MACE-II with flexible appendages attached at the payloads. A component-based formulation is used to derive the dynamics in a Linear Fractional form.

The first control problem addressed is a TV plant, where configuration changes in MACE-II with flexible appendages are commanded. Gain scheduling is identified as a suitable control technique, and different gain scheduling schemes are presented as candidates for implementation. The second control problem addressed is a TV narrowband disturbance, where the effect of disturbances introduced by reaction wheel imbalances on the payloads are minimized. By scheduling the control gains based on the wheel spin rate, disturbance rejection is improved over conventional linear design techniques.

MACE-II is currently slated to fly in the summer of 2000.

The main objective of NASA's New Millennium program is to demonstrate key technologies that will be used for future space missions. One important mission, especially for future space interferometer missions, is the Space Technology 3 (ST3) New Millennium Separated Spacecraft Interferometer mission, which is a two spacecraft interferometer. In fact, this mission will be the first interferometer that will be launched.

The MIT Space Systems Laboratory has been involved in many aspects of this mission–ranging from determining the optimal imaging locations for the spacecraft to implementing the interferometer's optical control system. Currently, the MIT SSL is partnered with two industrial teams vying for a contract to design and develop the ST3 interferometer.

Over 45 students were involved in the Technology Laboratory For Advanced Composites (TELAC) during AY 1998—99, including 16 graduate students, 18 UROPers, and 12 students in 16.621/2 who performed their research projects in the laboratory. In addition the laboratory hosted a visiting research engineer: Cao Qikai from Shenying Aircraft Research Institute, China for the entire year as well as one international student for a period of six months. Six students finished their master's theses in the laboratory during this period and one doctorate was completed. The laboratory issued a total of 23 reports during the past year including a number accepted for publication in journals and conference proceedings. Laboratory personnel participated in conferences at the national and international level giving a total of 20 presentations. Important progress was made in a number of research areas throughout the year. These include the development of mechanism-based models for the elevated temperature fatigue of titanium-graphite hybrid composite laminates; the development of mechanism-based models for the damage tolerance of composite sandwich structures; experimental and numerical work to better understand the response of composite shells to transverse loading which simulates damage-causing impact events; extension of models for the damage tolerance response of pressurized composite cylinders to general anisotropic lay-ups; extension of analytical methods for the calculation of interlaminar stresses in arbitrary laminates at free edges to more general loadings and to ply-drop configurations; investigation of the reliability of solder and adhesive joints under piezo-loading; further development of the active transonic composite compressor blade; the initiation of a project to investigate the use of distributed anisotropic actuators to improve aeroelastic response of highly-flexible composite wings; the initiation of work to investigate the effects of large displacements of high aspect-ratio wings on low-order unsteady aerodynamic modeling; the use of a high-fidelity composite beam model to obtain three-dimensional stress estimates. A research partnership has been established with Draper Laboratories focused on developing technologies in support of an artillery launched aerial vehicle. This has included work on aeroelastic modeling and associated wind-tunnel testing of a six-segment folding wing concept, the analysis and testing of composite parts under very high accelerations and the development of overall design methodologies for such vehicles. A research collaboration has been initiated with Sikorsky Aircraft on "Fatigue/Damage Tolerance for Composite Structures." Additional relationships are continuing with the Boeing Company and Rockwell International.

Once again, a significant event during the year was the "Student Symposium on Composite Materials" held for the fourth time this year with continued participation by and between the students working on composites at Virginia Tech, and those in TELAC at M.I.T. This year the event was held at MIT in May with Prof. Mark Spearing as the local organizer. The University of Massachusetts at Lowell was invited to participate on a trial basis and Professors Julie Chen and James Sherwood and ten of their students attended. Julie is a graduate of the Laboratory for Manufacturing and Productivity at MIT.

The primary test activities fell into two classes. The first is the use of the wind tunnel for educational purposes. In the past year there were three 16.621-16.622 projects.

The second were commercial use of the wind tunnel for anemometer calibration for Second Wind, Inc.; aerodynamics of spinning cylinders for Sanders Assoc.; boat sling for Army Natick Laboratory; and wing flutter tests for Draper Labs.

The Wright Brothers Wind Tunnel is the only privately owned pressurized wind tunnel in the United States. This feature gave use to an extended program with the Environmental Protection Agency to calibrate their smoke stack probes at the same Reynolds number as encountered in use. That is, the Reynold's number in a hot stack gas can be simulated by testing in air at low pressures.

The 16.622 testings used 16 hours, and commercial testing used 27 wind on hours this year. Tests included ground wind distribution near MacGregor Hall which resulted in a prize paper at Student AIAA Conference; drag of racing wheelchairs; and drag of ski boots.

The Yngve Raustein Award established in 1993 by the family and friends of Yngve was given to Yassir Azziz, a sophomore from Casablanca, Morocco, whose intellectual curiosity, positive attitude, and dedication exemplify the spirit that Yngve Raustein brought to Unified Engineering.

The David Shapiro Memorial Award was given to Carolina Tortora, a junior from Englewood Cliffs, NJ, to pursue summer research on microgravity investigation and crew reactions in 0-gravity at the Politecnico di Milano, Milan, Italy; Marc E. Carreno, a senior from Tulsa, OK, to support travel and research at several European universities and aerospace companies to determine how the next wave of engineers is being prepared. A team of six juniors–Allen Chen of Newton, MA, Mark Kepets of Flushing, NY, Jacob Markish of Chelmsford, MA, Sumita Pennathur of Foxborough, MA, Ryan Peoples of Medford, NJ, and Charles Toye of Longmeadow, MA–was also awarded the Shapiro award to design, build, and fly a high speed electric powered model aircraft in the 1999—2000 AIAA/Cessna/ONR Student Competition.

The James Means Memorial Award for Excellence in Flight Vehicle Engineering was given to Elizabeth M. Walker, a senior from Sherborn, MA, for design of the avionics and controls system of a next generation general aviation jet aircraft.

The James Means Memorial Award for Excellence in Space Systems Engineering was given to twin brothers, both seniors from Washington, D.C., Adam J. Matuszeski and Thaddeus B. Matuszeski, for significant contributions, initiative and leadership in the development of the space systems design project, Mission Mirage: A Technology Demonstrator for Extracting Lunar Ice.

The Pratt and Whitney Prize was given to seniors Kari A. Bingen of Portland, OR, and Tyra E. Rivkin of Hoffman Estates, IL, for their outstanding achievement in the design, construction, execution, and reporting of an undergraduate experimental project to characterize the wake field of an alpine ski boot and make modifications for drag reduction.

The Admiral Luis De Florez Award For Original Thinking Or Ingenuity was given to Man-Fuk Koo of Kowloon, Hong Kong and Jeffrey G. Reichbach, a senior from Valley Stream, NY, for outstanding ingenuity in designing, constructing, and testing a single-needle colloidal thruster prototype; and to Christopher E. Carr, a senior from Seattle, WA, in recognition of his leadership and contributions to the NIMBLE–NonInvasive Microgravity Biomedical Life Sciences–experiment which flew successfully on the NASA KC-135A "Weightless Wonder" research aircraft in March 1999.

The Leaders for Manufacturing Undergraduate Prize was awarded to seniors Benjamin D. Boehm of Valrico, FL, and Stephanie J. Thomas, of Lawrenceville, NJ, for taking the initiative to solve significant manufacturing challenges associated with adhesively joining piezoceramics in order to investigate the piezo-induced fatigue of such joints.

The Apollo Program Prize established in 1995 in honor of the Apollo Program Chair Endowment was given to senior Tyra E. Rivkin for her leadership in developing and flying PREVIEW, a peripheral vision microgravity biomedical experiment, successfully flown at NASA's Johnson Space Center, Houston, Texas, on-board the KC-135A "Weightless Wonder."

The Henry Webb Salisbury Award established by the family and friends of Henry Salisbury was awarded to seniors Keith Amonlirdviman of Chicago, IL, and Stephanie J. Thomas of Lawrenceville, NJ, for outstanding work in the completion of the undergraduate degree program in the Department of Aeronautics and Astronautics at the Massachusetts Institute of Technology.

Terran K. Melconian, a junior from Reading, MA, is also the 1998—99 recipient of the General James H. Doolittle Memorial Scholarship.

The student chapter of the American Institute of Aeronautics and Astronautics (AIAA) awarded the department's undergraduate teaching award to Prof. Earll Murman.

Professor S. Mark Spearing received the chapter's departmental advising award.

The late Professor Marten Landahl was posthumously awarded the Sigma Gamma Tau Society departmental graduate teaching award.

The department has now begun to move in its strategic direction and is implementing plans for new thrusts in System Engineering and Architecture, Information Engineering, the Engineering Context of Education, Research and Educational Program. The next year will focus continuing to recruit the faculty to implement this new vision, implementing the action plans, and forging relationships with industry necessary to accomplish our goals.

Edward Crawley

MIT Reports to the President 1998-99