5-James Webb Space Telescope- $8.8 billion
Number 5 on our list is a planned space observatory optimized for observations in the infrared.
Named after James E. Webb, the second administrator of NASA, this project is in panning since 1996.
The mission’s capabilities will enable a board range of investigations across many sub-fields of astronomy.
Its main reason is to observe some of the most distant objects in the Universe including the very first stars and the formation of the first galaxies, beyond the reach of current space based instruments.
It is known that the mission had major cost overruns in the past, which got it under review for cancellation by the United States Congress in 2011.
But in November the same year, Congress canceled the cancellation and instead added additional funding to complete the project at $8 billion.
