[Launch Alert] Friday Vandenberg Launch

Wed Dec 9 23:08:22 EST 2009

                             LAUNCH ALERT

                              Brian Webb
                     Ventura County, California
		             kd6nrp at earthlink.net
                     http://www.spacearchive.info

                             2009 December 9 (Wednesday) 19:59 PST
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                            TWILIGHT EFFECT

Regarding Friday's Vandenberg launch, space analyst Rick Baldridge
wrote:

"From my calculations, the rocket gets into sunlight 3 minutes 15
seconds after launch (if launched about 6:09:33 am PST Dec. 11th) --
with MECO about 1 minute 10 seconds after entering sunlight."

Rick has been very accurate in the past, so it's likely that since
Friday's launch occurs at dawn, we will see a Twilight Effect as the
first stage's exhaust plume is illuminated by the Sun after the
Delta II climbs out of the Earth's shadow.

However, since the sunlight will be reflecting off of the plume
rather than shining through it (as would occur during a dusk launch),
the display will probably be interesting, but not spectacular.

Refer to the following page for a photo of a similar Delta launch
during dawn from several years ago:

  www.spacearchive.info/delta-ii-iridium-ms-11.htm

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                           LAUNCH SUMMARY

Launch: Delta II/Widefield Infrared Survey Explorer (WISE)

Date: 2009 December 11

Launch Window: 06:09:33-06:23:51 PST (14:09:33-14:23:51 UTC)

Launch Site: Pad SLC-2W, Vandenberg AFB

Vehicle: Boeing Delta II with three strap-on solid rocket motors

Launch Heading: Toward the south (196° flight azimuth)

The following table is a listing of flight events for this launch:

 Time                                                    Altitude
(mm:ss)                       Event                    (nautical mi)
-------     -------------------------------------      -------------

00:00       Liftoff 
00:36       Mach 1 
00:50       Maximum Dynamic Pressure 
01:04       Solid Rocket Motors Burnout                    8.8
01:39       Jettison Solid Rocket Motors                  16.9
01:40       Begin Dog-Leg Maneuver 
02:20       End Dog-Leg Maneuver
03:15       Vehicle Emerges from Earth's Shadow
            (probable Twilight Effect)
04:24       First Stage Main Engine Cutoff (MECO)         56.9
04:32       Staging
04:38       Second Stage Ignition                         62.7
04:56       Payload Fairing Jettison                      69.7

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                              RESOURCES

Please consult the following sources for information related to
Friday's Delta II/WISE launch.

Launch Viewing Locations and Information

  www.vandenberg.af.mil/questions/topic.asp?id=745

  www.spacearchive.info/vafbview.htm

Launch Photography

  www.spacearchive.info/vafbphoto.htm

Mission Background

  www.nasa.gov/wise

Launch/Countdown Status

  www.nasa.gov/wise

  www.spaceflightnow.com

Launch Webcasts

  www.nasa.gov/wise

  www.nasa.gov/ntv (NASA TV)

NASA TV is reportedly available on Dish TV channel 213 and Direct TV
channel 376.

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