3. SLS and Orion
It is an American space shuttle which is super heavy that was launched to explore the surface of Mars. It is a two-stage program that is going to make its first flight in 2020. This mission costs $23bn in total.
Cost: $23bn (estimated)
4. Apollo Space Program
Also known as Project Apollo was launched by NASA as a third Human spaceflight program. It accomplished safe landing of humans in 1969-1972. This project costs $109bn.
5. Global Positioning System
It is a radio-navigation system owned by the U.N and the United Nation Air Force. It satellites in the 31st orbit of the earth. It was first launched in February 1978 and costs $12bn.
6. Hubble Space telescope
The Hubble Space Telescope is a low Earth orbit that was launched in 1990. It is the largest and the most versatile among the other conventional space telescopes. It costs $10bn in total.