Efficient and stable clock signal generation requirements at extreme temperatures (-180C to +450C)and radiation (>250 Krad TID) are not met with the current solutions.Chronos technology proposes to design and fabricate RTXO as a new, comprehensive and scalable solution that simultaneously addresses the attributes of a reliable clock source in extreme environments. RTXO offers very small form-factor 5X7mm surface mount device utilizing high-Q Quartz material and CMOS/SOI for the extreme cold temperatures of Mars surface up to +110C. For extreme high temperature (to +450C) it uses Silicon Carbide (SiC-4H) semiconductor technology, high quality Gallium Orthophisphate (GaPO4) piezo-electric resonator material in a non-adhesive configured innovative assembly. All the different elements and processes used in the RTXO technology have been investigated in phase I to comply with the intended performance. This includes the individual elements, packaging, interconnecting method and manufacturing processes. RTXO offers standard signal interface, wide operating voltage range, conventional microelectronic packaging, and industry standard and reliable metal to metal as well as glass to metal sealing processes. RTXO delivers its exceptional performance over a wide (application specific) frequency range to 100 MHz from a single supply voltage and requires very low power.