[AZ-Observing] Re: Thursday Photo Op

Here are some "tech" notes on the contrails from the Minotaur launch on Thurs. 
evening.
I have seen several launches from Vandenberg from Phoenix -- most notably the 
IRAS spacecraft launch years ago, when I was working for Lockheed at Luke AFB 
west of Phoenix.  A couple years ago many amateur astronomers saw a DOUBLE 
launch that occurred during the RTMC conference at Big Bear Lake, CA.

Evidently the upper stage plume expands and dissipates rapidly, presumably 
since it is at very high altitude and low pressure.  It is a little surprising 
to realize how high the booster is when we see the final burnout -- by then the 
satellite payload is nearly in orbit, clear of the atmosphere!

The booster stage contrail (water vapor, at lower altitude) typically gets all 
twisted up by the upper air shearing winds, thus the "corkscrew".  It does not 
dissipate so rapidly, and typically remains visible in the sunlight "over the 
horizon" for some time.

Note that thursday night's launch was presumably into a polar orbit, thus
the "left turn" to the south.  This is typical for military recon launches from
Vandenberg.  Polar orbit launches from there do not pass over any major 
population centers.  During the "Star Wars" interceptor missile series a few 
years ago, there were
frequent launches to the west, crossing the Pacific over Johnston Island
(from which the interceptor missile was launched), with descent and splashdown
on the Ronald Reagan Test Range in the Kwajalein Atoll, Marshall Islands, 2,500 
miles S-SW of Hawaii, or about 4,800 miles from Vandenberg!

The Minotaur is a rocket constructed at Orbital Sciences in Chandler, AZ.  Uses 
a Minuteman lower stage, plus a "Taurus" middle stage, evidently four stages in 
all.  The satellite was a DARPA Streak package. Here are more web resources:

Spaceflight Now news story on 09-22-05 Minotaur launch (good California 
photos) http://www.spaceflightnow.com/index.html

Brian Webb Space Archive web pages (Vandenberg AFB launch info)
http://www.spacearchive.info/index.htm

Info on Orbital Science Rockets (built in Chandler, AZ by Spectrum Astro)
http://www.orbital.com/SpaceLaunch/
Launch on 09-22-05 was a Minotaur ground-launched missile.
http://www.orbital.com/SpaceLaunch/Minotaur/index.html
http://www.orbital.com/SpaceLaunch/MinotaurIV/index.html

A little bit of info on the DARPA Streak payload
http://armscontrolwonk.com/

Gene Lucas(17250)

Jack Jones wrote:

>>From son Jeff in San Diego:
>It was awesome.  Very large in the sky here, it was actually west of me, over
>the ocean. People were pulling over and getting out of their cars to look at 
>it.  Pretty neat. After awhile the trail looked like it did a loop-de-loop, 
>which I thought was interesting... It was literally 'blasting across the sky' 
>for about 30
>seconds.
>
>Jack
>  
>

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