The United Launch Alliance (ULA) launch of a Delta II rocket carrying two STSS-Demo satellites for the U.S. Missile Defense is now scheduled for Friday, September 25, with a one hour launch window of 8 - 9 a.m. EDT, from Space Launch Complex 17-B at Cape Canaveral AFS, Florida. The small leak in the fuel transfer system under the launch pad was fixed. Mission managers met at 9 a.m. EDT today and gave the official “Go for launch.”  The weather forecast calls for a 70 percent chance of acceptable weather during the launch window. Unless further launches are purchased, this will be the next to last launch of a Delta II from Cape Canaveral.

Launch Preview:
The Space Tracking and Surveillance System, or STSS, is a program that was originally proposed in the 1980s by the Strategic Defense Initiative Organization. Originally known as the Space Surveillance and Tracking System, it was envisioned as a system to track ballistic missiles from Low Earth orbit. It grew into a program named Brilliant Eyes, which later became the SBIRS-Low component of the US Air Force’s Space-Based Infrared System. In 2002 the Missile Defense Agency took over the program, and it became known as STSS.

The STSS-Demo satellites were originally built as demonstrators for Brilliant Eyes, and later SBIRS. After a decision was made to proceed with the operational programme without conducting test launches, the two demonstration satellites were stored. In 2002, this decision was reversed, and the demonstration satellites were revived as STSS Block 2006.

The two satellites were built by Northrop Grumman, with their sensors being produced by Raytheon. They have a combined mass of 2,244 kilograms, and are attached to each other, with the lower satellite, SV-2, being attached to a component designated as an “Orbital Insertion Stage”, which will function as a Payload Attachment Fitting.

The launch will use the Delta II 7920-10C configuration. At launch the first stage, an Extra-Extended Long Tank Thor, will augmented by nine GEM 40 solid rocket motors. Once the first stage has completed its burn, the second stage, a Delta-K, will ignite to complete the ascent and place the satellites into orbit.

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