Oct 10 1974
From The Space Library
RobertG (Talk | contribs)
(New page: 10-30 October: NASA launched Westar 2 (Westar-B) , the second U.S. commercial domestic communications satellite, for Western Union Tele-graph Co. from Eastern Test Range at 6:53 pm EDT...)
Newer edit →
Current revision
10-30 October: NASA launched Westar 2 (Westar-B) , the second U.S. commercial domestic communications satellite, for Western Union Tele-graph Co. from Eastern Test Range at 6:53 pm EDT on a Thor-Delta launch vehicle. The satellite was placed in a close-to-planned transfer orbit with a 36 107-km apogee, 231-km perigee, and 24.76° inclination. The apogee kick motor, fired 13 Oct, circularized the orbit with 35 766-km apogee, 35244-km perigee, 23-hr 42-min period, and 0.5° inclination. By 25 Nov. the comsat was operating normally at its station at about 90° W longitude above the equator.
The launch had been twice delayed, once for investigation of the entire Delta program and once for a last minute check of a connector pin. When launched, the vehicle performed as planned with two minor exceptions (both due to human error) : the 2nd-stage cold-gas redundant altitude-control system switched from primary to backup nozzles because the guidance system had been programmed with too low a moment threshold and the umbilical end fitting was damaged because a tether had been improperly installed. Neither problem compromised the NASA mission objective: to place the satellite in an orbit of sufficient accuracy for transfer into a stationary synchronous orbit while retaining sufficient station-keeping propulsion to meet the mission lifetime requirements. The objective was met, and the mission was adjudged successful 30 Oct.
Westar 2 joined Westar 1, launched 13 April 1974 and later placed in geosynchronous orbit at 99° W longitude. The Westar Satellite Communications System-consisting of Westar 1 and 2, a third satellite for later launch, and five ground stations-had the potential for general. purpose telecommunications throughout the continental U.S., Alaska, Hawaii, and Puerto Rico. Western Union planned to make the system available to all users, largely through leasing the voice, TV, and data transmitting services. NASA would be reimbursed for the launch. (NASA MORs, 1, 25 Nov 74; NASA Releases 74-147, 74-265; Westar Release, 12 Sept 74; SBD, 11 Oct 74, 214)
10 October: An electric rocket engine that short-circuited aboard Sert II Space Electric Rocket Test satellite in 1970 had been restarted in space and successfully operated for six weeks, scientists at Lewis Research Center reported. Launched 3 Feb. 1970 to demonstrate that electric propulsion could be used for future space missions, Sert II was to have operated an ion engine for six months in space. Engine thruster 2 shut down after less than three months of operation; thruster 1 performed for five months. Both failures were attributed to a small chip apparently eroded from a molybdenum grid and lodged between two grids at the back of the engine. William R. Kerslake, Sert II experiment manager, believed the chip was jarred loose in summer 1974 when the spacecraft was spun up by its cold-gas thruster system to obtain a better sun angle for solar arrays. Since then, the thruster had been operated successfully on 17 occasions for short periods, obtaining up to 80% of its maximum thrust. Electrical Propulsion Branch Chief Robert C. Finke said operation after 41/2 years proved "the long term storability of this thruster design" and indicated that the system could be "confidently incorporated into future missions requiring several years of thruster operation." (LeRC Release 74-60)
NASA had deleted a backup Viking lander spacecraft and would substitute the proof test orbiter for one of two flight orbiters to help offset significant cost increases and meet target dates for the two 1975 missions to explore the planet Mars, NASA reported to Speaker of the House Carl Albert. Technical problems in the guidance-and-control computer, biology instrument, and lander proof-test capsule qualification had delayed completion of the landers, made the schedule "extremely tight," and increased costs an estimated $48.8 million over the $89 million in the FY 1975 budget. NASA notified the House that it planned to use for Viking $48.8 million available from the Skylab program after its successful completion. (Text in Viking Proj Hearings, House Subcom on Space Science, 21-2 Nov 74)
NASA Was negotiating two 11-mo study contracts for assessing methods of producing electric power from coal. Funded by the National Science Foundation, Dept. of Interior, and NASA, the program would compare costs and impact on the environment of such energy systems as a potassium Rankine topping cycle, advanced steam plants, open and closed cycle gas turbine systems, supercritical carbon dioxide systems, magnetohydrodynamic systems, and fuel cells. Westinghouse Corp. and General Electric Co. had been selected to make the studies, to provide data for a Lewis Research Center energy systems model for evaluating variables. (NASA Release 74-273)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
