The four-channel 64 kbps per channel terminal that manages the INMARSAT link is Block 6 - HSD 400. Where is this terminal located?

• A. Overhead Cargo Bay Equipment Shelf
• B. Starboard Cargo Bay Equipment Shelf
• C. Port Cargo Bay Equipment Shelf
• D. Mission Processor Rack

Answer: (A)

The main idea is where specific communication hardware is assigned in the system layout. Block 6 houses the HSD 400, a four-channel 64 kbps per channel terminal that handles the INMARSAT link. This type of terminal is designated to be installed on the Overhead Cargo Bay Equipment Shelf, not in the Mission Processor Rack or on the side cargo bay shelves. The overhead shelf placement keeps external communication hardware organized near its interface points and power/cooling paths while staying separate from central processing gear, which helps with maintenance access and reduces potential interference. The other locations are reserved for different equipment roles, so they don’t align with the INMARSAT terminal’s designated placement.