ISS slow rotation

Ed Cannon (
Sun, 03 Jan 1999 02:23:50 -0600

Should we look for ISS maxima/minima?  A NASA update:


> Following the engine tests, flight controllers in the Zarya Flight 
> Control Room at Mission Control, Korolev - near Moscow, Russia - 
> maneuvered the station back into a naturally stable spinning 
> orientation to conserve propellant and moderate temperatures on 
> the spacecraft. Called an X-nadir spin, the orientation has the 
> Unity module pointed toward Earth and Zarya pointed toward deep 
> space with the station slowly spinning a few tenths of a degree 
> per second. It is the standard orientation for the station until 
> the arrival of Discovery in May. About once each week, however, 
> controllers turn on the station's steering jets and maneuver it 
> into position to update the guidance system and perform other 
> checkouts or activities as needed. 

One-half degree per second = 12 *minutes* per cycle; a pretty slow 
spin....  Maybe if people see a "flare" it's a maximum from this 
very slow tumble?

Ed Cannon - - Austin, Texas, USA