[amsat-bb] Cute competition winners
g7hia at btinternet.com
Wed Oct 28 10:31:01 PDT 2009
Cute Re-entry Competition
It seems that when a satellites, reache an altitude as low as about 170km they will be down very quickly. According to Space Track elements, and InstanTrak tracking software Cute was still orbiting when the perigee was below 150 Km.
My theory is that cubesats stay in orbit longer because they have a large mass relative to their very small cross section and so experience far drag than bulkier objects.
Using that idea I ran the last element set for several orbits and made an arbitrary decision that re-entry probably took place at a perigee of 130Km or so thus putting re-entry pretty much dead centre between two competition entries.
I therefore declare Ib OZ1MY and David G0MRF as joint winners !!!
On receipt of current postal addresses I will mail out a patch kit to each of the lucky winners.
Thanks to Ib, David and everyone else who took part, it was fun to plot the curves and I learned a bit about atmospheric density and solar flux.
73 John G7HIA
IPS Radio and Space Services, have a useful paper on satellite orbital decay calculations.
Thanks to Ken GW1FKY for sending me a copy.
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