Heres what I found if it helps ya....
A launch window is the time or set of times during a given day that the Space Shuttle can launch and still meet mission objectives and stay within safety guidelines. For example, one important safety constraint is to have a daylit Trans-Atlantic Landing (TAL) site. If the Space Shuttle were to have engine trouble and have to land before it gets to space, it would use a TAL site.
For example, the MIR rendezvous mission (STS-71), had only a
five minute launch window. Another example would be a Shuttle mission deploying a satellite destined for another planet. Because the Earth and the other planet have to be in a certain alignment to accomplish the journey with the engine and the amount of fuel on board, the mission might have a launch window of only a few days in a specific month.
A sample chart is shown below with explanations of the colored arrows. All times are shown in
GMT.
A. The time at which the sun has risen at the Kennedy Space Center and Edwards Air Force Base for the nominal End of Mission (EOM), EOM + 1 day (potential extension day), and EOM + 2 (another potential extension day). The 2-2-2 means that there will be daylight for 2 potential landing opportunities at each site for each of the 3 days. This window opening is valid at the nominal mission altitude (superscript 1).
B. Same as above, except that the information is valid assuming an orbit altitude adjustment sometime during the mission (superscript 2).
C. Similar to A, except that there is only 1 daylight landing opportunity at KSC for EOM+2 (2-2-1), and 1 opportunity each day at Edwards (1-1-1).
D. This vertical bar represents September 21, 1995, the launch date for USML-2. In the event of a launch delay of days or more, this bar slides to the right to whatever new launch date is projected.
E. This is the time at which the sun sets at the TAL site Ben Guerir, Morocco. This represents a potential closing of a launch window.
F. Same as E, but for Moron, Spain.
G. Same as E, but for Zaragoza, Spain. Now that we know all the constraints, what is the launch window for this example? If we choose Case A (without an altitude adjustment) and Case F (Moron, Spain as the primary TAL site), the launch window will open at 15:01 and close at 17:57 GMT.
,
