❄️ Spacecraft Radiator Sizing Calculator

Required area from rejected heat & temperature · net flux · cold-case heater check

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Hot Case (sizing)

Cold Case (check)

Results

Blackbody emission @ T
– W/m²
Net rejection flux
– W/m²
Required area (with margin)
– m²
Cold-case equilibrium T
– °C
Heater to hold T_min
– W
–
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📖 How to use

  1. Size in the hot case: max heat to reject at the max allowed radiator temperature, with the hot-case absorbed flux from the Environment tool.按热工况定面积：最大排热量 + 允许的最高散热面温度 + 环境工具给出的热工况吸收热流。
  2. Prefer anti-sun / deep-space facing placement — absorbed flux near zero doubles the effective capacity vs a sun-viewing face.散热面尽量背阳/朝深空布置——吸收热流接近零时，有效排热能力比对日面高得多。
  3. Then check the cold case: the same area with little internal heat gets cold; the tool reports the equilibrium temperature and the heater power needed to hold T_min — carry that into the Heater tool and the EPS power budget.再校核冷工况：同样的面积在小内热时会过冷；工具给出平衡温度与维持 T_min 所需加热功率——请带入加热器工具与电源功率预算。
  4. Use EOL optical properties (ε stays, α degrades up) — sizing at EOL hot case is conservative for area.采用寿命末期光学特性（ε 基本不变，α 退化升高）——按末期热工况定面积偏保守、安全。

Radiator sizing relations

Area: A = Q·(1+margin) / (η·(ε·σ·T⁴ − q_abs)) — emission minus the absorbed environment flux, derated by fin/coupling efficiency η.

Cold case: with the sized area fixed, T_cold = [(Q_cold/(η·A) + q_abs,cold)/(ε·σ)]^0.25; if below the minimum allowed temperature, heaters make up Q_htr = η·A·(ε·σ·T_min⁴ − q_abs,cold) − Q_cold.

Typical net capacities: an OSR radiator at 40 °C facing deep space rejects ~400 W/m²; a white-painted face seeing albedo/IR nets far less. Louvers or heat switches can cut the cold-case heater penalty.

All computation runs locally in your browser.

散热面设计关系式

面积: A = Q·(1+余量) / (η·(ε·σ·T⁴ − q_吸收)) —— 辐射减去吸收的环境热流，再按翅片/耦合效率 η 折减。

冷工况: 面积确定后，T_冷 = [(Q_冷/(η·A) + q_吸收,冷)/(ε·σ)]^0.25；若低于允许最低温度，需加热器补偿 Q_加热 = η·A·(ε·σ·T_min⁴ − q_吸收,冷) − Q_冷。

典型净排热能力：40 °C 的 OSR 面朝深空约 400 W/m²；看得到反照/红外的白漆面远低于此。百叶窗或热开关可降低冷工况加热代价。

全部计算在你的浏览器本地完成。