Once a satellite is on station in LEO, what is the most efficient way to move it to GEO?

• A. This cannot be done. A satellite cannot be moved from LEO to GEO without a rocket booster.
• B. By firing the satellite's coarse thrusters to generate a delta-V, thereby thrusting it into an elliptical orbit, then firing the coarse thrusters again to generate a second delta-V, thereby thrusting the satellite into a circular orbit.
• C. By increasing the speed of the momentum wheel to swing the satellite into the higher orbit.
• D. By pulsing the reaction wheel to swing the satellite into the higher orbit.

Answer: (A)

Raising from LEO to GEO requires adding orbital energy through external impulse, not just reorienting the satellite. The efficient way to do this is a two-impulse transfer using the spacecraft’s propulsion system. First, fire the thrusters to push the spacecraft onto an elliptical transfer orbit that reaches GEO altitude at its far end. Then, at the transfer orbit’s apogee near GEO, fire the thrusters again to circularize at geostationary altitude. This is the classic Hohmann-type transfer, which minimizes total delta-V for two coplanar circular orbits.

Internal attitude devices like momentum wheels or reaction wheels can only change orientation or rotate internal masses; they do not provide a net external thrust to raise orbital energy. So they cannot accomplish the orbital change required to reach GEO. The two-burn maneuver using the satellite’s propulsion is the method that actually moves the spacecraft from LEO to GEO.