Space Station Thermal Control Subsystem

This package simulates the Active Thermal Control System (ATCS) of a space station. It models how heat is generated, accumulated in station nodes, transferred to coolant loops, and finally vented into space through radiators.

The system is built on ROS 2 using actions, services, and topic publishers/subscribers to mimic the real flow of thermal energy inside a space station.

🌍 How It Works

The thermal control simulation runs as a closed loop, with the following steps:

1. Solar Heating

   • The sun_vector node publishes the position of the Sun.
   • The solar_heat_node converts this into heat input for the station’s thermal nodes.

2. Thermal Nodes Heat Up

   • The thermals_solver node integrates heat flow across all nodes and links (defined in a YAML config).
   • It publishes each node’s temperature on /thermal/nodes/state.
   • If average temperature exceeds a threshold, it triggers cooling.
3. Coolant Loop Activated
4. • thermals_solver sends an action goal to /coolant_heat_transfer handled by cooling.cpp (CoolantActionServer).
   • The coolant absorbs heat based on:

   \(Q = m \cdot C_p \cdot \Delta T\) * Internal water loop temperature is updated and published on /tcs/internal_loop_heat.

5. Heat Transferred to Ammonia Loop

   • The coolant loop transfers heat to the ammonia loop with efficiency losses.
   • This is published on /tcs/external_loop_a/status.

6. Radiator Venting

   • If ammonia heat exceeds a threshold, the CoolantActionServer calls the /tcs/radiator_a/vent_heat service.
   • The radiators.cpp (RadiatorController) handles this by commanding solar joints (via /solar_controller/commands) to rotate and dump heat to space.

7. Water Recycling

   • After several cooling cycles, the coolant server automatically:

     • Requests fresh water (/wrs/product_water_request).
     • Dumps used water into /grey_water.

8. Diagnostics

   • Throughout the process, nodes publish to /thermals/diagnostics to flag overheating, failed cooling, or service issues.

Nodes Overview

• thermals_solver Core simulator: integrates node temps, detects overheat, triggers cooling.

• cooling (CoolantActionServer) Action server for cooling: absorbs heat, transfers to ammonia, vents via radiator.

• radiators (RadiatorController) Handles radiator venting: rotates panels if excess heat > threshold.

• sun_vector Publishes Sun position for orbital heating.

• solar_heat_node Converts Sun position into actual heat load on nodes.

• on_demand_publisher Diagnostic publisher for one-off checks.

Launch

All nodes can be started together:

ros2 launch space_station_thermal_control thermals.launch.py

This will bring up:

• Thermal solver
• Coolant action server
• Radiator controller
• Sun vector + solar heating

Key Interfaces

Topics

• /thermal/nodes/state → Node temperatures

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