Revolutionizing orbital reentry with regenerative cryogenic cooling for reusable upper stages.
Render: Plasma sheath forming as regeneratively-cooled shield dissipates hypersonic heat
Orbital Reentry Reimagined
Traditional reentry vehicles rely on ablative or ceramic tile shields that degrade or require intensive refurbishment.
Gatkul’s regenerative hydrogen-cooled heat shield is a next-generation solution designed for orbital-class reusable vehicles.
By actively circulating cryogenic hydrogen through shield-integrated microchannels, extreme heat is absorbed and diffused
before damaging the structure — enabling safe, repeatable reentry.
How It Works
🌀 Active Cooling: Supercooled liquid hydrogen flows through microchannel coils embedded in the heat shield surface
🔥 Thermal Absorption: Reentry heat (~1500–2000°C) is absorbed by the hydrogen via conduction and convection
💨 Phase Transition: Hydrogen evaporates, carrying heat away from structural elements
🌫️ Boundary Layer Control: Ejected hydrogen may form a cooling gas sheath reducing convective heat flux
🔁 Reusable Design: No burn-through or residue; shields survive multiple reentries with minimal inspection
Advantages Over Conventional Shields
♻️ Fully Reusable: No erosion, melting, or replacement needed after reentry
📉 Lower Maintenance: Eliminates the need for tile inspections or ablator layering
⚙️ Integrated System: Shares cooling loop with LOX/LH2 propulsion systems for efficiency
🚀 Higher Payload Ratio: Lightweight design reduces TPS mass and increases usable mass to orbit
Applications in Gatkul Vehicles
🔵 Trishul Upper Stage: Human-rated reentry with high-frequency reuse
🟠 PADMA Crew Return Stage: Deep space return with extended heat loading
🔄 Orbital Refuelers: Precise aerobraking and capture maneuver survivability
Engineering Considerations
🛡️ Shield Composition: Carbon-carbon with hydrogen channels milled via EDM
📏 Channel Geometry: Optimized for even temperature distribution and minimal flow impedance
⚠️ Control Systems: Redundant sensors and venting valves to maintain flow balance
🧊 Fuel Synergy: Draws from vehicle’s main hydrogen tank or an auxiliary boil-off buffer
Development Milestones
2023: Arc-jet testing of regenerative shield panels
2024: Subscale reentry demonstrator (high-alt balloon drop test)
2025: Full-scale shield on orbital testbed flight with Trishul
2026: Human-rated certification for crew return systems
Rethinking Reentry for the Reusable Era
Gatkul's regenerative hydrogen-cooled heat shield represents a leap forward in thermal protection system design.
It supports our vision of rapid, reliable, and reusable launch systems that can operate with aircraft-like efficiency.
As space becomes a place for habitation, industry, and exploration, reentry technology must rise to meet the challenge.
