[Launch Alert] Pegasus Rocket Launch

Tue Apr 24 08:53:03 EDT 2007

                             LAUNCH ALERT

			            Brian Webb
		         Ventura County, California
		         E-mail: kd6nrp at earthlink.net
	         Web Site: http://www.spacearchive.info

				             2007 April 24 (Tuesday) 04:47 PDT
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                    NASA TO LAUNCH AIM SPACECRAFT
                     Vandenberg AFB News Release

VANDENBERG AIR FORCE BASE, Calif. – Vandenberg is scheduled to launch
an Orbital Sciences Pegasus XL vehicle Wednesday, April 25 carrying
NASA’s Aeronomy of Ice in the Mesosphere (AIM) spacecraft. The Pegasus
launches from beneath an L-1011 carrier aircraft which will depart
Vandenberg’s runway before dropping its payload approximately 100
miles west-northwest of the base. The launch window extends from 1:23
to 1:30 p.m. The last Pegasus launch was March 22, 2006 carrying
NASA's Space Technology 5 spacecraft into orbit.

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			       MISSION BACKGROUND

Detailed information about the AIM mission is available on the
Internet at http://aim.hamptonu.edu.

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			        COUNTDOWN STATUS

A good source of countdown status for the Pegasus XL/AIM launch may be
the Spaceflight Now web site (www.spaceflightnow.com). On launch day,
search the site for a page with launch status. Once you find it, be
sure to regularly hit the refresh button on your browser to see the
latest information.

NASA TV may also provide coverage of the launch. To access NASA TV
over the Web, go to www.nasa.gov/ntv.

NASA TV is available on an MPEG-2 digital C-band signal accessed via
satellite AMC-6, at 72 degrees west longitude, transponder 17C, 4040
MHz, vertical polarization. In Alaska and Hawaii, they are on AMC-7 at
137 degrees west longitude, transponder 18C, at 4060 MHz, horizontal
polarization. For digital downlink information, visit
www.nasa.gov/ntv.

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

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                           LAUNCH VIEWING

Before I discuss the subject of launch visibility, it's first
necessary to describe the events leading up to the launch. On launch
day, a jumbo jet carrying the rocket will leave Vandenberg AFB about
an hour before launch. The L-1011 will likely be accompanied by one or
more smaller chase planes.

The aircraft will first head west over the water. They will then make
a series of three right turns. They will make their first turn and fly
north and parallel the coast. Before the formation reaches San Jose,
it will turn again and briefly head east towards shore. The planes
will execute a third turn and fly south as they follow the coast.

The L-1011 will release the Pegasus at 39,000 feet at 36.000 degrees
north, 123.000 west. This places the drop point above the ocean 75
statute miles southwest of downtown Monterey.

The contrails from the L-1011 and chase planes should be visible along
the coast from San Simeon to San Jose. The actual launch will be very
hard to see. Observers to the north will have the best view since they
will be looking up the back of the rocket. Under very good conditions,
a keen-eyed observer might see the tenuous smoke trail from the launch
as far south as Refugio Pass in the mountains north of Santa Barbara.

If you plan to photograph the contrails from the aircraft or the smoke
trail from the rocket, try to use a polarizing filter to darken the
sky background and make the contrails or smoke trail stand out.

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                        E-MAIL CONSIDERATIONS

In the days leading up to a launch, I'm often very busy and have a
hard time answering questions via e-mail. Many questions about launch
viewing and photography can be answered by reading the following
pages:

   www.spacearchive.info/vafbview.htm

   www.spacearchive.info/vafbphoto.htm

Following a launch, I receive anywhere from a handful to literally
hundreds of e-mails. I can be flooded with incoming launch
observations and photos and my e-mail access incapacitated.

To prevent any problems, I ask that you do the following:

   - Only send images that are of high quality

   - Send no more than three images

   - Do not send any photo, video, or other attachments larger than
     750 kB.

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