How Does the Launch Window Affect Our Mission Planning?

A long launch window gives us the greatest flexibility to checkout possible problems and verify that the STS is ready to launch safely, so we design them to be as long as possible.

Because every minute spent on-orbit is a precious resource, and many of the experiments have complex operating procedures, we plan the mission "timeline" of events far in advance of the launch. By using MET for our timeline, we minimize the changes resulting from the exact time of launch.

There are three categories of mission events:

Launch time independent
Earth-fixed events
Ephemeris dependent

Our premission planning is done based on a launch at the very beginning of the launch window (the most common time we launch). If we launch sometime later in the window, we must adjust the timeline.

We have a team of engineers in the Payload Operations Control Center who update the timeline in 12-hour segments, which are then "faxed" up to the crew onboard.

Updated July 28, 1995. Contacts