I have received some private mail confirming that the small ISS boost was indeed occuring as a side-effect of vernier RCS control by the Shuttle. But as Kevin Fetter has remarked it seems to be much smaller in scale to what we have seen last year. It is still worth to keep an eye on it over the next few days as long as Atlantis is still docked to the ISS. Among other things it also *tweaks* my prediction for an upcoming Saturday sun transit of the ISS/Atlantis near my place which I would find interesting to watch given the new addition to the ISS! On a related theme if you check the orbit elements for the ISS and the Shuttle as posted by NASA on spaceflight.nasa.gov/realdata/elements you find them treated as two seperate spacecraft and not one docked system. Each has its own mass, cross section area (or correspondingly different drag coefficients for the TLEs) leading to seperate trajectories. A spot check I did for this evening showed a difference in position of about 2 km between the two (using the correspinding arcs valid for the moment)! Gerhard HOLTKAMP Darmstadt, Germany ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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