USA 179

	USA 179	Lincoln, UK 2010 Mar 11, UTC Thursday
Maintained by: Robert Christy FBIS Contact: Zarya Home Page SDS Home Page USA 179 Background USA 179 Orbit USA 179 Switching USA 179 in 2006 USA 179 early in 2007 USA 179 late in 2007 USA 179 early in 2008 USA 179 ndot/2	ndot/2 Through long-term measurement of the Mean Motion, it is possible to monitor how its natural rate of change varies with time. The technique is periodically to measure the slope of the straight lines in the plot of Mean Motion against time. This plot shows measured values of ndot/2 from June 2006 through to August 2007. The value changes cyclically between bounds of .0000100 and .0000132. The line of best fit varies between .0000102 and .0000127. However, peaks and troughs do not repeat exactly from cycle to cycle. The trough in Autumn 2007 was not as low as the previous one. The period is about ten months which coincides with the length of time taken for the orbit plane to complete one rotation round the Earth's polar axis when measured against the line joining the Earth to the Sun. In all probability, the variation is solar driven in some way (gravity or solar wind?).	Radio Frequencies Frequency lists, transmission details Satellite Tracking Techniques, analysis and results of tracking activities Zarya Diaries Consolidation of individual mission diaries from the site (and more!) Orbital Events Ongoing Calendar of comings and goings in space The Kettering Group People, reminiscences and tracking equipment Sputnik Korolyov's efforts in getting the first satellite into orbit Luna The Soviet Union's programme of automatic exploration Vostok First pilot to orbit the Earth Voskhod Soviet programme to put multiple passengers into space Soyuz 4 and Soyuz 5 First docking in orbit of piloted spacecraft ASTP First docking of piloted spacecraft from different nations Salyut Chronology of missions to the first space stations Mir Detailed calendar of launches and activities in orbit ISS Mission calendar for the early years