At 22:17 19/07/02, you wrote: >..... >Can somebody explain why the majority of rocket bodies I observed last night >do not seem to be tumbling and hold a steady magnitude? I always assumed >that LEO rocket bodies would be tumbling bits of space junk heading for >eventual re-entry. James, Firstly just geometry. Rocket bodies vary in brightness mostly just because of the instantaneous cross section, so if your line of sight is close to roatation axis you see little change in brightness. Secondly the the rotational energy of satellites in LEO which are conductive, is removed slowly because of the eddy current damping in the Earth's magnetic field. If the rocket body is a length/width of more than 4 or so its tumble priod will increase to 1 rev/orbit and then it will lock into the gravity gradient. Tony Beresford ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Sat Jul 20 2002 - 02:22:57 EDT