How about some aerodynamic lifting during perigee as a result of a fixed orientation then? Bill On Nov 22, 2011, at 9:41 AM, "George Roberts" <gr@gr5.org> wrote: >> Is there a way to calculate kinetic energy of Phobos-Grunt vs time to see >> if energy has >> been added to the system (thrusters, leak) or if it's just been >> redistributed (circularization)? > > The middle part of Ted's graph shows that the orbit is decaying overall. In > other words the orbit has less potential and less overall energy (but more > kinetic - this is the nature of lower orbits). > > However, even though it has decreasing energy mostly due to drag, it takes a > significant amount of energy to change PG's orbit in the way it seems to > have changed. Energy other than drag. More energy than expected from > "solar wind". This suggests thrusters or a leak. The best way to explain > the anomaly to me is that PG is maintaining an orientation such that it is > always pointed to the same star as it orbits the earth and it is constantly > thrusting towards that star. This would explain the increase of one half of > the orbit and excessive decrease of the other half. > > - George Roberts > http://gr5.org > > _______________________________________________ > Seesat-l mailing list > http://mailman.satobs.org/mailman/listinfo/seesat-l _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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