Error correction codes are a means of including redundancy in a stream of information bits to allow the detection and correction of symbol errors during transmission. In Forward Error Correction (FEC) it is desirable to have low Bit Error Rates (BER) and low decoder complexity for reliable data transmission Turbo code is a great achievement in the field of communication system. Turbo code also consists of an interleaver unit and its BER performance also depends on interleaver size. This paper presents a low complexity turbo decoder for CCSDS (Consultative Committee for Space Data Systems) telemetry channel coding standard. Simulations are done in MATLAB to assess the BER performance of the design in an AWGN channel. Log-MAP decoding algorithm is less computationally complex with respect to MAP (maximum a posteriori) algorithm, without compromising its BER performance. A register transfer level (RTL) turbo encoder is designed and simulated using Hardware Description Language. Index Terms: Turbo decoder, CCSDS, Log-MAP