Satellites are expensive, their access could be stolen. They needs protection to minimize threats effects. Imagine that your country decided to launch a mission to monitor their natural resources using Remote sensing satellite. What happen if the access of this satellite was taken and instead of its expected benefits it became a danger source that introduces a free images for your competitors, or by another word it could be spy satellite instead of remote sensing satellite. Imagine if your company decided to launch a satellite for business, the satellite captures the image upon paid request what will be done if this image available for free or even for less price. According to this level of danger the satellite should be protected. many directions should be studied. Is the security function implementation is by software or y hardware. Where is the location of the security function in he network model? What are the consequences of inserting security layer to the network model? What is the security protocol? What are the security services? What are the algorithms and how to update the system from broken one? How to change the key with which policy?