Pegasus Launch Alert: California & SW U.S.
Sun, 28 Feb 1999 16:51:25 EST

There is a scheduled Pegasus launch Monday evening (March 1, 1999) being
staged from Vandenberg AFB.  The launch
window begins at 6:51:50 PM PST and extends for 10 min.  Florida Today Space
Online reports that the expected drop time from the L-1011 is at 6:57 PM PST.
I haven't researched every detail so could be wrong to a degree but using the
previous Pegasus launch as reference, the Pegasus rocket carrying NASA's Wide
Field Infrared Explorer (WIRE)
satellite will be dropped from the L-1011 aircraft at about 39,000 ft.
altitude.  Once dropped, it ignites about 5 sec. later
and flies level briefly before adopting an upward attitude thus achieving many
thousands of feet additional altitude in the
following minute or two.  It is dropped from the L-1011 about 100 miles
southwest of Monterey, California.  It travels in a
southerly direction (polar orbit).  By the time it is due west of Los Angeles
it will be at a very high altitude and thus will
be rather high above the western horizon (30-40 degrees??), higher than the
Delta II rockets appear from Los Angeles
after launch from Vandenberg.  It will be evening twilight so with clear
weather (hopefully), should be worth looking out for.  

I saw the previous Pegasus launch from Burbank (Los Angeles area), which had
launched just after sunset.  When first
spotted in the northwest, it looked much like a normal jet contrail but moving
faster.  Then the contrail stopped (stage
burnout).  Then it had a short wedge shaped exhaust plume originating from a
very bright point of light as it approached
near due west high in the western sky.  By the time it was some past due west,
I could no longer see it even with binoculars, perhaps having achieved its
orbital altitude.  By happenstance, Dave Ransom, STS Plus tracking software
creator, saw it from central Arizona!  He had commented that it was beautiful.
Monday's launch could be visible from
much of Arizona and Nevada, maybe SW Utah as well as central California and
especially from southern California.
Don't miss it and be kicking yourself!  For those in Arizona or Utah, note
6:51 PM PST = 7:51 PM MST = 02:51 UTC. 

Concerning the previous Pegasus launch, see "Pegasus/SWAS Launch" SeeSat
thread below.  It was on Dec. 5, 1998.

In comparing the Dec. 5, 1998 launch with Monday's launch, if the launch point
and trajectory are not the same,
then Monday's launch path may not appear as high above the western horizon as
what I saw Dec. 5.  I remember reading about the Dec. 5 launch point being 70
miles off the coast, not 100, but the article referenced below indicates
100 miles off the coast.
Here's an article on Monday's Pegasus launch mission:

Florida Today Space Online is good for timely updates:

--  Jake Rees
    Burbank, California