1) The International Space Station – $150 billion
This is the one of the most expensive space projects and missions as well as the most expensive science experiment.
It’s the thing you see sometimes from the Earth when the sky is clean. It’s called the International Space Station and it’s one of the costliest investments in the history of science.
The construction of the ISS began in 1998 and it has been continuously occupied by researchers since 2000. The total cost of the construction of the International Space Station is around $150 billion.
Basically, the astronauts go in the space station to research how to live in space and how future missions to Mars and the moon could be achieved most effectively.
cover via: dovemed
With all that being said, we end up our article about most expensive science experiments.