Quantity
Value used
Solar constant at 1 AU
1,361 W/m²
Stefan, Boltzmann constant σ
5.670 × 10⁻⁸ W/m²K⁴
Standard gravity g
9.80665 m/s²
Earth gravitational parameter μ
3.986 × 10¹⁴ m³/s²
Orbital velocity at 650 km
≈ 7.53 km/s
Aluminium density
2,700 kg/m³
Multi-junction cell efficiency
30%
Radiator emissivity ε
0.85
Effective LEO sink temperature
200, 270 K
Radiator areal mass
5, 12 kg/m²
Array specific power
~150 W/kg
Rack convention
200 kW, 1.4 t, $3.5M
Formulas used throughout Rocket equation: Δv = I_sp · g · ln(m₀/m_f) Radiative heat rejection: q = ε σ (T⁴ − T_sink⁴) Plane change cost: Δv = 2 v sin(Δi/2) Drag deceleration: a = ½ ρ v² C_d (A/m) Beam divergence: θ ≈ λ / D