Communications satellites are now facing a challenge to meet the growing demand for connectivity and to handle large volume of data at very high speeds but they must be a profitable solution for operators and photonics-related technologies offer great promise. The increasing volume of information being transferred through the satellite puts more constraints on the payload electronics that has to transfer data at rates in excess of 10 Gigabit per second per lane (Gbps/lane). At those rates, electrical signal pre-compensation is done at a higher cost in terms of power consumption on standard copper-based RF electronic and switching to optical fiber medium become a preferable option. GEO and LEO satellites optical interconnect technical requirements are: mechanical ruggedness, low weight, low power consumption and radiation tolerance. If they integrate specific and advanced material and technologies, optical interconnect can meet space mission’s requirement. Constant temperature cycling, operation under vacuum and operation under radiation are just few of the environmental conditions that the optical modules must perform in. Lifetime expectancy for GEO mission has to exceed 15 years. In order to have reliable communication link over 15 years mission, the electro-optics parameters must be selected properly. The effect of the VCSELs bias on the communication performance at the beginning of life (BOL) has to be studied in order to maximize the end of life (EOL) communication link budget. We will show how those parameters have been obtained. Illustrations of hardware and description of the relevant qualification tests and results will be also be shown to explain how the challenges have been overcome.