October 1975

From The Space Library

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Current revision

Air Force scientists under contract to NASA had completed a study of the physiological effects on man resulting from transfers from one atmosphere to another during the 15-24 July Apollo Soyuz Test Project. The difference between the Soyuz 7031-kg-per-sq-m atmosphere of 30% oxygen and 70% nitrogen and the Apollo's 3515.5-kg-per-sq-m 100% oxygen represented the transition between 3048 m and 8230 m in altitude. In 1973, scientists, using a hyperbaric chamber to simulate spacecraft environment, had found that volunteer subjects showed symptoms of decompression sickness (the bends) when moving from one atmosphere to the other. During the following year the scientists had found a way to lessen the chance of decompression sickness: The most satisfactory procedure was to increase the time allowed for denitrogenation (breathing 100% oxygen at ground-level pressure). This helped to remove excess nitrogen cause of the bends-from the body. The Air Force study had helped NASA and Soviet ASTP planners schedule the actual transfers. (ASFC Newsreview, Sept 75, 8)

A 50 000-kg towing tractor, first piece of operational ground-support equipment manufactured by International Harvester Co. for Kennedy Space Center's Space Shuttle operations, was accepted for delivery to KSC. The T-500S Paymover tractor would tow NASA's Boeing 747 carrier aircraft or the orbiter, or the mated 747-orbiter combination after use at the Flight Research Center, Edwards, Calif, during orbiter tests. (KSC Release 257=75)

A new computer-controlled tracking device for telescopes, called VIP (video inertial pointing), had been developed at Ames Research Center to improve the aim of balloon-borne, airborne, and space telescopes. The two main functions of VIP were to help the astronomer steer the telescope, and to continuously update the automatic stabilization system that holds the telescope steady during viewing. Automatically stabilized telescopes heretofore had used gyroscopes to keep the telescope aimed at a point in space and counteract the rotation of the earth and other disturbances; gyroscopes had been found subject to drift, causing the telescope to wander off target. VIP, using a single video sensor, could generate the signals required for all three control axes-roll, pitch, and yaw-and could use the visual information to point at nonvisible (infrared) sources. Previous systems using star trackers had needed from two to six conventional sensors to do the same job.

Development of VIP had made use of several state-of-the-art devices: the microprocessor, a complete digital computer on a single printed circuit card, was the computer inside the VIP electronics. Two types of video sensors used by VIP were the solid-state imaging device called a CCD (charge-coupled device) that incorporated a matrix of light-sensitive elements on the surface of a silicon chip measuring 0.01 mm on a side, and an advanced vidicon tube for night vision called an ISIT (intensified-silicon intensified-target) camera. By reducing the amount of hardware required for good performance, use of these new instruments had lowered the cost of the system. Ames would use VIP to provide accurate automatic pointing of the Spacelab Infrared Telescope Facility for the Shuttle that was under development at Ames and on contract. (Ames Astrogram, 9 Sept 75, 1)

NASA had awarded a $45.8-million contract to Radio Corporation of America Astro-Electronics Div. to design and build eight Tiros-N third generation meteorological satellites. The 635-kg Tiros-N (Television InfraRed Operational Satellite) would have 4 times the payload capacity of the previous generation of metsats, and was expected to be able to forecast weather 2 days in advance with accuracy equal to the 1-day predictions. In addition to providing day and night imagery, the Tiros-N spacecraft would take atmospheric and sea-surface temperature readings; measure proton, electron, and alpha-particle activity surrounding the earth; and collect data from weather platforms on balloons and from ocean buoys. (GSFC Goddard News, Sept 75, 1)

The Mass. Inst. of Technology Lincoln Laboratory, under contract to the Air Force, was developing an experimental ground electro-optical deep-space surveillance (GEODSS) system to scan nighttime skies for orbiting and geosynchronous satellites. The system was being installed at White Sands Missile Range, first of a proposed five-site GEODSS worldwide surveillance network. The network would augment the Air Force's Aerospace Defense Command's spacetrack coverage which maintained a day-by-day count of all satellites and. debris circling the earth.

GEODSS combined two sophisticated telescopes with electro-optics, a TV camera, and a digital computer, as well as system-related equipment. Mounted at the focal plane of the larger telescope was a TV camera to transmit the signal to the observatory control room for instant screening and analysis. (AFSC Newsreview, Sept 75, 14)

The Air Force had successfully test-flown an F- 111D turbofan jet engine with all-composite third-stage fan blades 40% lighter than conventional titanium fan blades. The tests-made at Edwards Air Force Base-marked the first military flight evaluation of a rotating structural engine component made of composite materials. Objectives of the flight-test program were to determine long-term environmental effects on the material and to verify potential operation and maintenance cost benefits. Use of composites could provide a 15 to 20% weight savings in jet engines, allowing increased payloads or extended range. (AFSC Newsreview, Sept 75, 1)

Limitations imposed by the Strategic Arms Limitation Talks (SALT) agreements had made the development of the B-1 bomber essential, the Air Force Systems Command Newsreview reported Secretary of Defense James R. Schlesinger as telling Rep. Richard Bolling in an interview. Because the U.S. would be limited in megaton strike capability and approximately 60% of U.S. megatonnage was carried by bombers, it was essential to maintain a significant and highly effective bomber force. (AFSC Newsreview, Sept 75, 2)

Two visiting research associates working under 2-yr associateships awarded jointly by NASA and the National Research Council completed their research at NASA. While at NASA Dr. Ditmar Kranzer of the Technical University of Vienna, Austria, had designed and fabricated charge-coupled devices on silicon and sapphire wafers. This type of electronic device would be used as part of an electronic circuit for imaging, storage, and signal processing. The device had a high speed capacity, a low power requirement, and a very high packing density, which would decrease the number of outside connections needed for the circuits and reduce the area required for data storage.

Dr. Tsuneo Yoshikawa had developed steering laws for single gimbal and double-gimbal control-moment gyro systems during his 2yr tenure at NASA. These laws, which apply to any spacecraft requiring highly accurate attitude-control systems, had been formulated in an effort to minimize performance deterioration. (MSFC Release 75-213, -219)

According to International Telecommunications Union figures, a satellite had been launched every 3 days in 1974. Of the total of 124 launched, 18 belonged wholly or partly to the U.S., and the Soviet Union accounted for 95. (GSFC Goddard News, Sept 75, 3)

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