Derek Breit, Tim Luton, Mike McCants, Steve Newcomb, Jim Nix, Alberto Rango, Brad Young, and I, contributed observations used to determine the following element set. OTV-1 402 X 421 km 1 36514U 10015A 10152.14625136 .00000000 00000-0 00000-0 0 06 2 36514 39.9890 115.7066 0014500 288.9656 70.9583 15.52671698 01 Arc 20100527.08-0601.16 WRMS resid 0.188 totl 0.020 xtrk It appears that the object manoeuvres frequently - probably several times per week, perhaps almost daily - in order to maintain a nearly constant mean-motion near 15.5267 rev/d. I base this on the rather large time residuals of our observations, which tend be a significant fraction of 1 s, much greater than the 0.1 s or better that we routinely achieve. I estimate that such drag-negating manoeuvres would require about 10 m/s total delta-V over the reported maximum mission duration of 270 days, probably accounting for no more than a few percent of the total available. The launch weight of the X-37B is about 11,000 lbs (5,000 kg). A Sep 2003 NASA Facts document (FS-2003-09-121-MSFC) claimed that the dry weight of its X-37 would not exceed 7,500 lbs (3400 kg). Assuming that is true for the X-37B (perhaps a big if), and if all of the wet mass is hydrazine propellant, than the total delta-V would be about 1,100 m/s, of which about 100 m/s would be required for de-orbit. I consider those fairly rough estimates; does anyone have better information? Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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