Hi Gents, I have been working on an excel spreadsheet regarding ARISSat-1, orbital decay and atmospheric density. Its a small workbook with some calculations and a chart. The idea is to work out the volume that ARISSat-1 sweeps through per orbit, then calculate the mass of atomic material it will colloid with. Math is NOT my best subject . Is there a math guru on the list willing to take a quick look and tell me if I am on the right lines. Let me know and I will send it off list. Thanks John G7HIA _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb