This paper proposes a high temperature (HT) and radiation tolerant silicon carbide (SiC) technology that is comprised of integrated circuits and complementary power devices for use in power applications such as spacecraft motor drive modules for robotic science probes. This work evaluates the capability of SiC power semiconductor devices, in particular 4H-SiC DMOSFETs (double-implanted metal oxide semiconductor field effect transistors) and Schottky barrier diodes (SBD) for applications in >400°C harsh environment power electronics. Novel structures for the 4H-SiC DMOS and SBD are proposed and the temperature dependent characterization of relevant device parameters such as: channel resistance, device junction capacitances are performed through simulating device models. In this work, a complete proof-of-concept of HT non-inverting buck-boost (NIBB) DC-DC converter using the proposed MOS electronics is designed and fabricated, which is demonstrated to operate at ambient temperatures as high as 600°C. For verification of the proposed semiconductor modeling, a simulation study is performed in LTSpice on a NIBB converter that incorporates the developed SiC device models and converts 20V-80V input to 60V-100V output at an efficiency over 92% with rated power of 200W for stepper motor driver application.