Iridium 24 situation report

Wed, 1 Apr 1998 10:32:10 -0600

Hello everyone: 

Last night I had alerted a number of people in the Houston area to attempt
to observe IR24. Nobody observed a flare and almost nobody observed the
spacecraft with binoculars. If you take a look at the elements, IR24 is in a
slightly higher orbit than normal and the drag term has been jumping around
a bit.

IR24 has been placed in 'thruster attitude control mode'. For us it means
that there will be no reliable flare predictions for at least several weeks.
The signal that things are going back to normal will be a lowering of the
orbit down to the nominal mean motion profile. Thruster attitude control has
actually boosted the orbit.  

The last plane of the constellation will soon be populated if the Proton
launch goes off successfully today. 

Other status info: IR 11,  which had been reversed by 180 degrees in
orientation, is also in thruster attitude control mode and is expected to be
fully operational by mid June. In fact, by mid June all planes are expected
to be populated and cell phone testing by ground users is to start.  The
Iridium system should be online for commercial use by September.

Paul D. Maley
United Space Alliance
DO5/Cargo Operations
NASA Johnson Space Center
Houston TX 77058 USA

tel. 281-244-0208
latitude 29.6049 north, longitude 95.1086 west