Re: Delta II Iridium launch
Fri, 6 Nov 1998 11:47:20 EST

I also saw it launch from 130 miles away east of VAFB.  It was still dark
here, in the western sky.  I watched with 8x56 binoculars and recorded it
with a camcorder mounted to the side of the binoculars.   It was slated to
launch at 5:37:52 AM PST with a 5 sec. window.  Having seen a few VAFB
Delta II launches from that same location in my neighborhood, I knew what
to expect.  But, I almost was faked out, thinking it had not launched because
it was about 45 sec. after the launch time before I saw the small bright
orange flame-streak rise over the top of a low tree on the horizon.  Its
trajectory curved it in the usual southerly direction.  After acquiring with
binoculars, I did not look at  the watch anymore but am using a published
launch sequence of events to tie in with my observations.  The orange flame-
streak continued until about 2:10 into the launch when the 3 air-lit SRM's
burned out.  Then it just became an orange point of light and flickering
were intermittently seen behind it for a few seconds.  These sparks were, of
course, the 3 SRM's after jettison.   The orange point of light (main rocket)
at first had no contrail but gradually showed a contrail which over the next
min. or so got brighter and thicker.  When the contrail (or plume) got the
thickest and brightest, the beginning of it had a proportion which reminds
me of the same curve and wideness as the shape of a blimp.  The plume
was being produced by the main engine, which at this time, was a bright white
point of light.  At main engine cutoff (MECO) the point of light suddenly
diminished in intensity and the plume production was suddenly halted.  This
happened at 4:20 into the launch.  At this time the rocket is about SW of my
viewpoint.  As it got farther away, what I saw were several points of white
grouped side-by-side flickering and then gradually fading from view.  Now, I
don't understand why it was several points instead of just one but that is
I saw. 

Referring back to the wide plume, I believe the sun was still just slightly
far below the horizon for the plume to catch direct sun rays.  The white plume
was high enough to receive scattered twilight only.  It is this wide, blimp-
plume (with a narrowing plume trailing behind) that will catch the attention
average folk and sometimes result in much media coverage after the event.
This is especially true if the launch occurs a bit after sunset and thus this
plume is backlit by sun rays from the just set sun in the evening when more
people are out in the much populated southern California area.  I recorded the
Boeing satellite launch feed on one VCR and the local KNBC-TV live news
program on another VCR.  In reviewing the KNBC tape, it was interesting that
they covered the launch, after it was under way, with a live telephoto shot
their news helicopter showing about 50 sec. before, and up to just after the 3
air-lit SRM's burnout and separation.

-- Jake Rees
   Burbank, California