1. United States
Agency: National Aeronautics and Space Administration (NASA)
Budget: $18 billion
Ever since Neil Armstrong set foot upon the Moon, NASA has been the leading space agency in the world. Even though its funding has shrank to just 0.50% of federal budget from its heyday in the 60s when it was 4.41%, various private investment in space exploration like Space Exploration Technologies Corporation or SpaceX more than supplant US space program, helping make America the most advanced country in space technology.
