The author outlines the theory and implementation of an uplink power control (UPC) technique for Ku -band VSATs (very small aperture satellite terminals). The proposed uplink power control algorithm uses a VSAT outlink signal for a pilot or 'beacon' reference; it requires no extra space segment for power-level monitoring. A control loop holds satellite EIRP (equivalent isotropically radiated power) constant by modifying the earth station EIRP to compensate for uplink rain attenuation. The C/N estimator technique can be extended to low-cost VSAT stations by sampling the I-channel and Q-channel of the PSK (phase-shift keying) data demodulator. Ultimately, UPC saves operational costs by reducing static power margins. >