Simulation studies were performed to estimate the Total Ionizing Dose (TID) on the radiation detector (MURaD) designed by TUBITAK UZAY. MURaD contains 3 sensors. NurFET is the first sensor on MURaD and it is a p-channel MOSFET manufactured by the Nuclear Radiation Detectors Application and Research Center (NURDAM-Turkey). The second sensor is RADFET VT01 and it is a p-channel MOSFET manufactured by Varadis (Ireland). The third sensor of MURaD is Floating Gate Dosimeter (FGDOS) manufactured by IC-Malaga. This study presents the first TID analysis results to be utilized in the design phase. In this study, TID levels for different shielding materials and different thicknesses were calculated for a satellite orbiting at an altitude of 800km. Polymethyl methacrylate (PMMA), SiO2 (alpha-quartz), Aluminum (Al), and Lead (Pb) were chosen as shielding materials. For each shielding material, TID levels were calculated with FASTRAD software for corresponding thicknesses, i.e. 0.5, 1, 2, 3, 4, and 5 mm. Thirteen (13) Silicon (Si) point detectors were created for conceptual CubeSat (3U class), and TID levels were observed for each point detector. These detectors are located and defined such that each inner and outer face of the geometry includes one (1) point detector. In addition, one (1) point detector is located at the center of the CubeSat.