Satellite is a part-space tech (it is researched before the "Space age"). It can be researched for 10.000.000 GC and can be launched for that same amount. It carries a small fuel tank and can be launched anywhere. It has a radium of 5 tiles and boosts your relationship with the nation above (+1 Relationship per city), or you can make your people happy (+1 Happiness per city). It can be merged with Space Platform to create a mega sattelite, and can be merged with a space platform, a mega satellite and 2 other satellites to create an Ultra Satellite.
Mega Satellite is a space tech, because it requires a space platform. It is formed when a space platform and a satellite mege and costs totally 11.000.000 GC. It can cover 10 tiles, instead of 5. It can be merged with 3 normal satellites and a space platform to create an Ultra Satellite.
Ultra Satellite is a space tech, too. It is formed when a mega satellite, a space platform and 3 normal satellites, which costs 42.000.000 GC. It covers 15 tiles. It can be merged with 99 other ultra satellites to create a global satellite, a space wonder.
Global satellite is a space wonder. It is formed when 99 ultra satellites merge, costing 42.000.000.000 GC. It gives bonus relation to all nations, plus the wonder relation. It will give negative relation to other nations who had satellites. Satellites will remain, but they won't have an use.