Sea Launch User's Guide

Spacecraft adapters
(SCA)
The SCA mechanical interface with the spacecraft can be either a bolted
or a typical clampband (Marmon-type) interface. The specific spacecraft
interface information for the bolted and clampband based adapters is
provided in section 7. Spacecraft separation is achieved by redundant
initiation, which causes the separation of the retaining bolts or clampbands.
Payload structure
(PS)
The PS acts as a physical support for the spacecraft during horizontal and
vertical operations and functions as an environmental barrier. It is a
graphite-epoxy composite structure.
One-way valves in the PS allow airflow out of the payload unit, and prevents
backflow of air from the Block DM-SL cavity. The closeout membrane,
located at the upper diameter of the payload structure, provides a
barrier that limits thermal and contamination exchange between the
Block DM-SL and the spacecraft.
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