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With respect to short carrier locking time from a transponder working in an LEO (Low Earth Orbit) satellite, details on constraints of carrier acquisition and tracking are discussed by analyzing the thermally sensitized characteristics of the transponder. A half-way carrier acquisition and tracking method is presented to cancel the frequency sweep process in the uplink. With low Doppler shifts and high signal power, the carrier can be rapidly acquired to extend the available telecommand window when the satellite is running over the zenith. The validated results have shown that the transponder temperature telemetry has an orbital period varies in which the temperature is low in the earth shadow and high in the sun, and has an annual period during which the temperature is low in summer and high in winter, and has a long term rise of 0.3°C each year. While the transponder temperature varies from 25.9°C to 26.2°C, the carrier locking time changes linearly between 30s and 0. With the presented method, more than 6s can be obtained to send orders in the uplink for emergent operations or anomalous event disposals to support the life extension of the payload.