Rocket Burn Visibility

Ron Lee (ronlee@pcisys.net)
Fri, 09 Jul 1999 11:34:25 -0600

My recent posts on the Delta/Globalstar burn visibilities raises
issues about what such an event would look like.  Since I have 
never seen one, I have to rely on previous sightings as a guide.

I believe someone in the NE USA saw a Delta burn a year or two ago
and Mike McCants saw a Centaur burn in the recent past.  Both are
liquid propellants.

This seems to eliminate the concern about liquid versus solid.  My
initial thought was that solids would eject more particulates
making them easier to see (if sunlit).

Then there is the issue about when the cloud will appear relative
to the firing time.  Will the cloud expand slowly becoming more
visible perhaps a minute or two after the firing?   I will leave this
to others to provide answers so we can know what to expect when this
launch occurs.

As far as saying one or more of the burns is visible in the central
USA region, each observer will have to assess his twilight/darkness
conditions.  Two days ago I went out and was able to find suitable
guide stars even though it seemed too light.  My suggestion is to
try to observe this event if you are interested even if it might
appear questionable at first glance.  Of course each launch delay
improves the sky conditions for us east of the Rockies.

Ron Lee