Iridium double flare source
MALEY, PAUL D. (paul.d.maley1@jsc.nasa.gov)
Mon, 29 Jun 1998 08:01:50 -0500
In a recent post, Ed Cannon wrote:
"Iridium 40 had two maxima of about equal magnitude; the second
was about 25 seconds after the predicted flare. I'm still
wondering about the cause of these double flares. Could they
arise somehow from the satellite reorienting itself or moving
its solar panels at the time of the unpredicted flare?"
I have been looking at these double flares which occur sometimes from
various IR spacecraft. They are not caused by the satellite reorienting
itself, though the solar panels cannot be completely ruled out. The time
between maxima seems to be about 22 seconds. There is a battery radiator
panel associated with each MMA whose physical alignment is slightly offset
from the MMA. This panel may be the source of the secondary flare. The two
specific events I have logged accurately have occurred before the time of
predicted flare maximum, however. The battery radiator panel has a constant
orientation relative to the MMA as opposed to the cross link antennas which
are much smaller and are offset at far larger angles. The battery radiator
panel is also flat and specular like the MMA's.
Paul
Paul D. Maley
United Space Alliance
DO5/Cargo Operations
NASA Johnson Space Center
Houston TX 77058 USA
tel. 281-244-0208; fax: 281-244-1140
email: paul.d.maley1@jsc.nasa.gov
latitude 29.6049 north, longitude 95.1086 west, elev 6m