DoD SBSS (Space-Based Surveillance System) Launch


Message posted by Matthew Ruch on July 05, 2010 at 16:12:13 PST:

The launch has been delayed, but the correct
date is July 17 2141-2155 PDT (July 18 0441-0455 UTC).

That would place the launch at roughly 85 to 100 minutes after sunset at the launch site. Like the Pegasus and Minotaur I boosters, the Minotaur IV uses
four stages with a long delay between stage 3 burnout and stage 4 ignition.

These facts had us wondering if the Minotaur IV would climb out of the Earth's shadow and allow the Sun to illuminate the stage 4 exhaust plume and
create an artificial comet visible over a very wide area
(http://www.spacearchive.info/minotaur-jawsat.htm).

However, a technical analysis by Rick B. indicates that for the Minotaur IV/SBSS launch, the vehicle will not be sunlit at any point during the boost phase (stage 1, 2, 3, or 4 burns).

Despite this, the launch should be easily visible to the naked eye for hundreds of miles and the Minotaur will probably look like a moving yellow or orange light or star. The Minotaur IV uses a Peacekeeper ICBM first stage. That particular rocket motor (which is also used by the Minotaur I), is fairly bright.

From a distance of 100 miles east-southeast of the launch site, the stage I burn will look like a point of light with a visual magnitude of about -0.2
to -0.5 (refer to http://www.spacearchive.info/peacekeeper-gt-28pa.htm and
http://www.spacearchive.info/peacekeeper-gt-33pa.htm).

From the same distance (100 miles), the second stage will have a visual magnitude of about +1.

Given the ground track of the Minotaur IV/SBSS launch, the event should be visible to the naked eye as far north as San Francisco and as far south as
mid-Baja California and inland as far as Reno and the California-Arizona border.

Regards,

Matt


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