🌪️ Spacecraft Disturbance Torque Calculator

Gravity gradient · aerodynamic · solar pressure · residual magnetic — worst-case sizing torques

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Orbit & Mass Properties

Aero & Solar Surfaces

Results

Gravity gradient
– N·m
Aerodynamic
– N·m
Solar pressure
– N·m
Residual magnetic
– N·m
Worst-case sum
– N·m
Dominant source
–
Field B used
– µT
Density ρ used
– kg/m³
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📖 How to use

  1. Enter the orbit and spacecraft properties — inertia difference for gravity gradient, areas and CP–CG offsets for aero/solar, residual dipole for magnetic.输入轨道与整星特性——重力梯度用惯量差，气动/光压用面积与压心-质心偏移，磁力矩用剩磁。
  2. The worst-case sum (all torques aligned) is the conservative sizing input; carry it into the Wheel Sizing tool.最恶劣合成（各力矩同向叠加）是保守的选型输入；请带入动量轮选型工具。
  3. Below ~600 km aero usually dominates deployable-heavy sats; magnetic dominates magnetically dirty smallsats; SRP dominates at GEO.约 600 km 以下大帆板卫星以气动为主；磁清洁差的小卫星以剩磁为主；GEO 以光压为主。
  4. Density uses a moderate-solar-activity table — check the high-activity case for VLEO.大气密度取中等太阳活动——超低轨请再核高活动工况。

Disturbance torque models (SMAD)

Gravity gradient: T_g = (3μ/2r³)·|I_max−I_min|·sin 2θ

Aerodynamic: T_a = ½·ρ·v²·C_d·A·(c_p−c_g) with v = √(μ/r)

Solar pressure: T_s = (S/c)·A_s·(1+q)·(c_ps−c_g), S/c = 4.5 µN/m²

Magnetic: T_m = m·B with B = M/r³ (equatorial) to 2M/r³ (polar), M = 7.96×10¹⁵ T·m³

These are worst-case magnitude estimates for actuator sizing — real torques vary over the orbit in direction and phase; cyclic components size momentum storage, secular components set dumping frequency.

All computation runs locally in your browser.

干扰力矩模型（SMAD）

重力梯度: T_g = (3μ/2r³)·|I_max−I_min|·sin 2θ

气动: T_a = ½·ρ·v²·C_d·A·(c_p−c_g)，v = √(μ/r)

太阳光压: T_s = (S/c)·A_s·(1+q)·(c_ps−c_g)，S/c = 4.5 µN/m²

剩磁: T_m = m·B，B = M/r³（赤道）至 2M/r³（极区），M = 7.96×10¹⁵ T·m³

以上为用于执行机构选型的最恶劣量级估计——真实力矩的方向与相位随轨道变化；周期分量决定角动量容量，长期分量决定卸载频度。

全部计算在你的浏览器本地完成。