STRUCTURAL DESIGN FOR LARGE SPACE TELESCOPES... 327 335 ...... 351 CONSIDERATIONS IN THE DESIGN OF ORBITAL TELESCOPES 389 C. E. LIFER AND R. E. JEWELL THERMAL DEFORMATION PREDICTION IN ORBITING OBSER- 401 JAMES B. MASON CONSIDERATIONS ON PRECISION TEMPERATURE CONTROL ... 417 LUDWIKI. SEIFERT PRECISION POINTING OF LARGE APERTURE, DIFFRACTION- 465 HERBERT F. WISCHNIA CONTROL TECHNOLOGY FOR LARGE ORBITING TELE 473 SCOPES. GORDON F. BULLOCK, FREDERICK R. MORRELL, AND AARON J. OSTROFF GROUP D-INSTRUMENTATION Co-Chairmen: James E. Milligan and Kenneth L. Hallam THE REQUIREMENTS, DESIGN, AND MANUFACTURE OF JOHN STRONG 485 THE REQUIREMENTS, DESIGN, AND MANUFACTURE OF OP- THE SPACE RADIATION ENVIRONMENT IN LOW ALTITUDE 495 MARTIN O. BURRELL AND J. W. WATTS, JR. IMAGE CONVERTERS AND IMAGE INTENSIFIERS. 501 MARTIN ROME ELECTRONOGRAPHY.. 511 JAMES A. HALL CAMERA TUBES EMPLOYING ELECTRON-IMAGING CHARGE 523 GERHARD W. GOETZE THE PERFORMANCE AND CAPABILITIES OF RECENTLY RALPH S. LEVITT NEW CAMERA TUBE DEVELOPMENTS. R. E. SIMON 583 PAGE THE IMAGE ISOCON AND RELATED DEVELOPMENTS FOR 591 GROUND-BASED ASTRONOMICAL OPTICAL DATA-HANDLING. 657 EDWIN W. DENNISON Welcome Address Wernher von Braun NASA George C. Marshall Space Flight Center I would like to extend a wholehearted welcome to the astronomers, the astrophysicists, and the astronomical engineers who have convened here at the Marshall Space Flight Center for a three-day workshop on the problems of optical telescope technology. Having spent almost three years in the project management of the Apollo Telescope Mount Project, which will deploy and operate several solar telescopes in orbit, we have great appreciation and deep respect for the multitude of technical and operational problems with which space astronomers are confronted. We hope that your symposium will be successful and that the environment of this Center will be stimulating and helpful in at least some of the topics which you plan to discuss. The Marshall Center has been known for a number of years as a place where large launch vehicles are designed and built. The latest member of the launch vehicle family, Saturn V, has been developed to launch the Apollo capsule on its flight to the moon. We expect that the landing on the lunar surface by two astronauts will be accomplished in July.* Although the design, fabrication, testing, and launching of vehicles has kept the members of this Center extremely busy during past years, and although the Apollo-carrying Saturn V still requires a very considerable amount of attention and care, we have always held the belief that launch vehicles alone do not make a full space program. They are the means to accomplish an objective, the objective being the exploration of a world that is not fully accessible to us from the surface of the earth. One of the most fascinating, most exciting, and most promising new fields of exploration which the young technology of space flight is opening for us is astronomy from orbit, where we can face the universe without having to look, as Fred Whipple put it, through the "dirty basement window" of the atmosphere. We are very happy about the prospect that our Center will be able to contribute with our technology, and hopefully with our science, to the great progress that space astronomy will undoubtedly make during the next ten or twenty years. The Apollo Telescope Mount, or ATM-A Project, which is scheduled for launch in 1972, is giving us the opportunity of learning firsthand about the many technical requirements that an astronomical satellite must meet in order to be successful. We feel that we have learned much, and we are confident that ATM-A will be a successful project. We realize, however, how much more we have to learn in order to ensure success for the follow-on program in space astronomy, which includes such ambitious projects as 3-meter, diffraction-limited, optical telescopes. For the space engineer, the multitude of problems includes the production of lightweight, high-precision mirrors; the alignment of complex optical systems; the design of extremely rigid but lightweight structures; achievement of almost perfect thermal balance; attitude control and pointing stability of unprecedented accuracy; and the handling and transmission of huge quantities of data. *On July 20, 1969 at 4:17 p.m. EST, Neil A. Armstrong and Edwin E. Aldrin, Jr., successfully landed the Eagle on the lunar surface. At 10:56 p.m. EST, Armstrong became the first man to set foot on the moon. Liftoff and rendezvous with the orbiting command module was accomplished July 21. |