Sea Launch User's Guide

Launch rehearsals
Two rehearsals are conducted before the ACS arrives at the launch site,
including the mission dress rehearsal (MDR). Participation of customer
launch personnel on board the ACS, spacecraft tracking and
communication systems personnel, and the spacecraft control center is
encouraged.
The MDR simulates prelaunch and postlaunch operations up through
spacecraft separation and completion of the Block DM-SL CCAM.
During these rehearsals, launch vehicle operations are simulated and the
launch vehicle remains safely in the hangar.
Successful completion of the launch rehearsals is a prerequisite to
launch.
Launch platform
stability
At the launch site, the launch platform is lowered to its semi-submersible
launch draft position of 22.5 m. Platform positioning and orientation are
maintained using global positioning system (GPS) inputs to a dynamic
positioning system of thrusters on board the platform. Stability is
maintained by an active trim and heel system that compensates for mass
movements atop the platform.
Weather
conditions
The launch may be accomplished in significant wave heights up to 2.5 m;
most of the waves in the launch regions are of low period and small wave
height.
Year-round
launch capability
The combination of benign weather, inherent platform stability, and
active leveling systems makes it possible to launch the rocket year round
in most expected weather conditions (see fig. 8-22).
REV B D688-10009-1 8-19