<p>Satellite-based positioning navigation and timing (PNT) system is the most fundamental and convenient application system in PNT fields now and in the future, thus the satellite-based PNT service system should be more and more robust, reliable and easy to be applied. Aiming at the weak service performance of the existing BeiDou constellation in the Antarctic and Arctic regions and the possible discontinuous problems in the autonomous orbit determination using BeiDou terminals on board of low earth orbit (LEO) satellites, we propose a scheme to optimize the BeiDou constellation configuration. A relatively optimized deep space PNT service constellation is designed in order to overcome the weak service capability of the BeiDou navigation constellation in deep space. We find that more satellites in the same orbital plane have better positioning geometry than increasing the number of constellation orbital planes. Furthermore, the idea of resilient satellite-based PNT service mode combining deep, high, medium, and low earth orbit navigation constellations is proposed, in order to improve the service capability of multi navigation constellations. To strengthen the satellite PNT service ability, the resilient strategies of on-board phased array antenna, on-board atomic clocks and satellite signal generator are proposed, in which the adaptively possible adjustment of signal power, signal frequency, signal modulation waveform and information format are discussed. Some examples to demonstrate the resilient satellite-based PNT application modes are given.</p>