Jan 6 1978
From The Space Library
Lewis Research Center reported it had signed a $24 million 1 yr contract with Honeywell, Inc., Avionics Division, St. Petersburg, Fla., for management and engineering support of Centaur inertial guidance. This automatic self-contained navigation and guidance system with a digital computer unit would permit Centaur to compute and adjust its flight for delivery of a spacecraft to a preselected orbit without ground command. The nation's first high-energy liquid-hydrogen liquid oxygen rocket, the Centaur, as an upper stage on both Atlas and Titan III boosters, had helped launch Voyager 1 and 2, scheduled to fly by Jupiter and Saturn in 1979 and 1980. (Lewis News, Jan 6/78, 2)
Preliminary analyses of Viking Orbiter 1 (VO-1) data on the Mars satellite Phobos revealed low density and a spectral reflectance and low albedo that suggested a composition similar to type I carbonaceous chondrites, reported Science magazine. VO-1 had obtained a spectacular picture sequence at 100km, an encounter by far the most demanding navigation performance of any interplanetary-spacecraft exploration to date. Since Phobos had a mean radius of only 11 km and was only partially illuminated when viewed during the flyby, the VO-1 position relative to Phobos had required accuracy of within a few kilometers. Imaging data had revealed small positive features (hummocks), small craters with bright ejecta blankets, dark material on the floors of some craters, large variations in topography, and an abundance of linear features resembling crater chains. Further analysis would refine density estimates to determine Phobos's origin. (Sci, Jan 6/78, 61)
January 6-7: NASA launched INTELSAT IVA F-3, fifth of a series of improved commercial communications satellites, at 7:15pm EST Jan. 6 from Cape Kennedy on an Atlas-Centaur into a transfer orbit. ComSat- Corp had fired the apogee kick motor Jan. 7, putting the satellite into near-geosynchronous orbit. After initial positioning at 74 °E the satellite would be moved to 60°E as backup to INTELSAT IVA F-6, and was scheduled to be on station at 63°E by mid-June.
INTELSAT IVA F-3 had an overall height of 6.99m and a diameter of 2.38m. Height of the solar panel was 2.82m. Liftoff weight was approximately 1515kg (33401b); in-orbit weight after apogee motor firing, 825.5kg (18201b). Design life was 7yr.
Ten INTELSAT IV and IVA satellites were currently in synchronous equatorial orbit over the Atlantic, Pacific, and Indian Oceans, providing full-time telephone, teletypewriter, data, and television services to 107 countries, territories, and possessions. The INTELSAT IVA had almost two thirds greater communications capability than the INTELSAT IV series, with about 6250 two-way voice circuits and 2 television channels in its system configuration. The number of operating transponders had increased from 12 to 20. Improvement of the antenna system had produced greater effective bandwidth through frequency reuse by beam separation: for Indian Ocean service, the east-pointed beam of INTELSAT IVA F-3 would illuminate Japan and Southeast Asia using a 320MHz bandwidth, and would reuse the same 320MHz bandwidth in the west beam illuminating Europe and Africa. In addition to eight east-beam transponders and eight west-beam transponders, four transponders connected to an earth coverage antenna would illuminate all stations in the Indian Ocean region.
The Communications Satellite Corp. (ComSatCorp), U.S. member of INTELSAT, would be management services contractor for the satellite system; ComSatCorp on behalf of INTELSAT would reimburse NASA under a launch-services agreement for costs of the Atlas-Centaur and the launch. The INTELSAT IVA program represented an investment by 101 nations of approximately $295 million (US); this launch had cost approximately $47 million ($18 million for the satellite and $29 million for the launch vehicle and related services). (NASA Release 77-250; MOR E-491-633-78-5 [prelaunch] Jan 5/78, [postlaunch] June 23/78; W Star, Jan 7/78, A-5)
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