During the last two decades special interest developed to utilize computer network technologies to spacecraft service telecommunication links. Packet Switched Satellite Service Communication system has been proposed. ESA-Telecommand standard was the protocol employed in this work for data transfer on satellite communication links This protocol is-chosen because-it- provides reliable and flexible data transfer facility. The implemented system is subdivided into three layers. The Physical Layer is implemented using the RS-232C serial link. The Coding layer is implemented using the ESA protocol, which is responsible for error detection and correction. The Transfer layer is implemented using the ESA protocol, which is responsible for error detection, as well as flow control between the Earth Segment and Space Segment. The software was written in c-t+ language using its powerful technique known as Object Oriented Programming. This technique treats data as a critical element in the program and does not allow it to be accessed by functions outside the class. The communication protocol has been implemented by software and tested by connecting two PCs through their serial communication, where one of them emulates the Earth Segment and the other emulates the Space Segment. Error detection and correction are discussed and analyzed. Results indicate that this system is highly tolerant to noise where the probability of erroneous command to pass through the system is less than 10-19 for a BER of 10-5 , which is practically zero. This work represents a step towards implementing a complete satellite On-Board Data Handling system.