The cabin and its support systems

ISRO’s orbital-module architecture separates the habitable crew module from the service module. The crew module provides a pressurized space, crew interfaces and systems needed for descent. The service module supplies support such as power, propulsion and thermal functions while the vehicles are joined in orbit.

This separation is functional. A system can be essential during orbit without being the part designed to bring people through atmospheric entry. When examining a diagram, follow what each module must do during each phase rather than assuming every component returns together.

A cabin needs more than oxygen. Pressure, carbon dioxide, temperature and humidity must remain within the applicable limits. Sensors, control equipment and the people using them all belong to that problem. A functioning sensor does not by itself remove heat or replenish a consumable.

Consider a classroom power budget of 100 units: cabin support needs 35, avionics 20 and communications 15. Seventy units are committed, leaving 30. Adding a 40-unit experiment would exceed the available supply by 10; the total must be reconsidered. These numbers illustrate budgeting, not Gaganyaan specifications.

Budget the connected cabin

Equipment may have backup functions, but two devices can still share one vulnerable power source. A reviewer therefore asks how a failure could travel through the system and what the crew or controller would notice. Counting duplicate boxes is not the same as proving independence.

For a lesson exercise, trace a failed cooling fan through temperature rise, sensor detection and a response. The sequence clarifies why environmental performance, electrical supply and procedures need to be tested together. It is a reasoning exercise, not an emergency operating instruction.