[Launch Alert] Rocket Launch Tuesday
Brian Webb
[email protected]
Mon, 11 Aug 2003 06:26:23 -0700
ASTRONOMY/SPACE ALERT FOR SOUTHERN CALIFORNIA
Brian Webb
Ventura County, California
E-mail: [email protected]
Web Site: http://home.earthlink.net/~kd6nrp
Reaching more than 2,190 e-mail addresses worldwide
2003 August 11 (Monday) 06:17 PDT
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ROCKET LAUNCH TOMORROW
A Pegasus XL rocket carrying Canada's SciSat-1 satellite is scheduled
for launch from California's Central Coast tomorrow evening. A
converted L-1011 airliner* will leave Vandenberg AFB at approximately
18:12 PDT and ferry the Pegasus to the launch point 74 miles southwest
of downtown Monterey.
The Pegasus is slated for release at 19:10 PDT during a launch
window that extends from 19:04:10 to 20:01:26 PDT. The vehicle will
free fall for five seconds before its first stage motor ignites.
The rocket will fly south down the Western Range. If things go as
planned, the vehicle will place the 330-pound spacecraft into a 400 NM
circular orbit inclined steeply to the equator.
After a brief checkout, SciSat-1 will begin studying the chemical
processes that control the distribution of ozone in Earth's
atmosphere.
*If my memory is correct, Orbital Sciences, the Pegasus launch
vehicle manufacturer and launch service provider, purchased the
aircraft from Air Canada.
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PEGASUS XL/SCISAT-1 COVERAGE
Spaceflight Now
The Spaceflight Now web site will provide SciSat-1 launch preparation,
countdown, and post-launch updates. Point your browser to:
http://www.spaceflightnow.com/pegasus/scisat1/status.html
Be sure to regularly hit the refresh button on your browser to see the
latest information.
NASA TV
NASA TV will cover the pre-launch press conference from Vandenberg
AFB today at 13:00 PDT and tomorrow's launch from 17:30 PDT through
spacecraft separation from the Pegasus.
NASA TV is broadcast on AMC-9, Transponder 9C, C-band, located at 85
degrees west longitude. The frequency is 3880.0 MHz. Polarization is
vertical, and audio is monaural at 6.80 MHz.
Click the "Watch NASA TV Now!" link for live Web cast at:
http://www.nasa.gov
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PEGASUS XL FLIGHT EVENTS
The following table is a generic listing of flight events for Pegasus
XL launches*. These parameters may vary for each mission, but should
be more or less correct for tomorrow evening's launch.
Time Velocity
mm:ss Event Altitude (fps)
----- ----------------------- --------- ---------
00:00 Release 38,000 ft 770
00:05 Stage 1 ignition 37,640 ft 1,450?
01:17 Stage 1 burnout 34.1 NM 8,269
01:35 Stage 2 ignition 47.5 NM 7,969
01:51 Payload fairing jettison 58.7 NM 8,892
02:48 Stage 2 burnout 116.7 NM 17,809
09:52 Stage 3 ignition 398.9 NM 14,864
10:57 Stage 3 burnout 400.0 NM 24,770
*Data from Figure 3-1 of the "Pegasus User's Guide", Orbital Sciences
Corporation, 2000 August. Flight events assume a Pegasus XL without
a Hydrazine Auxiliary Propulsion System launched from the Western
Range to place a 501-pound payload into a 90-degree inclination, 400
NM, circular orbit.
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LAUNCH VIEWING
If you're wondering if tomorrow's launch will be visible, the answer
is a qualified "yes", but you'll have to be at a good location and
know exactly where to look.
The L-1011 will depart Vandenberg AFB at about 18:12 PDT, make a right
turn, and fly up the coast. The jumbo jet will then make two right
turns and begin heading south.
When the L-1011, now flying at about 38,000 feet, arrives at 36.000
north/123.000 west, it will release the Pegasus. A few seconds later
the rocket's first stage motor should ignite. The first two stages
produce a white smoke trail, making the vehicle easier to acquire
visually.
Although daylight Pegasus launches are difficult to see, last June's
launch was seen along the coast from San Francisco to San Simeon. I
suspect it could have been seen much further south using tripod
mounted binoculars or an astronomical telescope.
The best strategy for observers along the coast north of San Simeon
would be to go to the coastal mountains above the haze and clouds and
use binoculars to scan along the jumbo jet's flight path. A chase
plane may accompany the L-1011. If you see contrails from two jets
flying in formation, you've probably found them.
If you're further south, locate the azimuth and elevation to the
launch point. Then aim tripod mounted binoculars or a telescope in the
right direction. Several minutes before the 19:10 PDT nominal drop
time, begin scanning the sky with your optics from the launch point to
several degrees to the south.
If you're using an astronomical telescope, use the finder scope to
acquire the vehicle and then look through the main optics for a
detailed view.
If you don't have a GPS set handy, use the following procedure to
determine the azimuth to the drop point:
1. Determine the coordinates of your observing location. Go to:
http://geonames.usgs.gov/pls/gnis/web_query.gnis_web_query_form
2. Calculate the bearing and distance to the launch point from your
observing site. Go to:
http://williams.best.vwh.net/gccalc.htm
3. Go to "Compute true course and distance between points".
4. Enter your location's coordinates the Lat1 and Lon1 fields.
5. Enter the launch point coordinates (36.000 or 36 00 00 north and
123.000 or 123 00 00 west) in the Lat2 and Lon2 fields.
6. Press Compute.
7. Read the bearing (azimuth) to the launch point from the Course 1-2
field. The range appears in the Distance field. Note that the
distance, by default, is given in nautical miles.
If you see anything, please send me a detailed report.
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CORRECTION
The previous issue of this newsletter contained an inconsistency
regarding the recent Minuteman III launch. It said the launch window
began at both 01:01 and 01:31 PDT.
It should have said the launch window was 01:31-07:31 PDT.
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GLOSSARY
ft Feet
fps Feet per second
mm:ss Minutes and seconds
NM Nautical miles. A nautical mile is 6,076.115 feet in length.
The statute mile used in everyday life is 5,280 feet long.
PDT Pacific Daylight Time