Engineering tools for spacecraft and mission sizing

Mission design & orbits

Radii, eccentricity, apsidal velocities, period, and eclipse duration from two altitudes.

Sun-synchronous inclination from altitude or altitude from inclination, with period and ground-track spacing.

Delta-v and transfer time between two circular orbits, with an optional plane change.

Propellant mass, wet and dry mass, Δv, and Isp from the Tsiolkovsky rocket equation.

EIRP, received power, and link margin for an RF downlink.

Array output at any Sun distance from panel area, cell efficiency, and incidence angle.

Required array power and battery capacity from orbit loads, eclipse, and conversion losses.

Steady-state spacecraft temperature from absorbed and emitted flux.

Wheel torque and momentum storage from worst-case disturbance torques and a slew requirement.