Heat Management & Radiators
Direct liquid cooling from AI chips to low-mass deployable radiators, rejecting ~1 MW of heat via high-emissivity panels pointed at deep space
Coolant Path & Direct Liquid Cooling
Direct Liquid Cooling from AI Chips to Space
Each H100-class accelerator stack is mounted on a cold plate inside the pod. A closed liquid loop (ammonia or advanced space-rated coolant) pulls heat off the cold plates, runs through pod manifolds, and feeds into the node-level radiator assemblies on the spine. The loop returns cooled fluid back into the pods, exactly like a terrestrial liquid-cooled rack, but scaled for zero-g and vacuum.
Low-Mass, Low-Cost Deployable Radiators
Radiators are thin, flexible panel assemblies that stow compactly for launch and deploy using a scissors-beam mechanism derived from ISS radiators.
Design targets:
- High area-to-mass ratio (m² per kg) to keep launch cost down
- Simple kinematics (one deployment degree of freedom + single rotary joint) to keep mechanisms cheap and reliable
- Panel construction optimized for mass-produced modules that can be swapped or added as thermal load grows
When deployed, panels are co-planar and gimballed so they present minimal cross section to the Sun, and maximal cross section to deep space, maximizing net infrared heat rejection.
Radiator Architecture (ISS-Derived Deployable Assemblies)
Architecture
2–4 deployable radiator assemblies mounted on short booms off the spine. Each assembly is analogous to ISS radiators (Oren & Howell style):
- Base / torque arm at the spine
- Rotary joint for pointing
- Long strip of flat, co-planar radiator panels deployed by a scissors-beam mechanism
Per Assembly Specs
• Deployed length: ~22–23 m (≈75 ft)
• Width: ~6–7 m
• Area: ~140–160 m² per assembly
• Total for node: scaled to ~1,700–2,000 m² effective radiator area for a 1 MW thermal load
Working Fluid & Operations
Working fluid: ammonia or advanced coolant loop; interpanel flex hoses with micrometeoroid/thermal shielding
Radiators gimbaled to stay edge-on to the Sun, normal to deep space. Panels are co-planar (do not face each other), maximizing view factor to cold space. Control modes coordinated with arrays so radiators avoid shadowing and back-heating.
Infrared Emission to Space
The radiator surface stack is tuned for high emissivity in the thermal IR band and low absorptivity in the visible / near-IR band. Almost all electrical input to the node ultimately leaves as IR photons from these panels, closing the energy balance for megawatt-class AI workloads.