Nancy Grace Roman, a renowned astronomer who led the drive to launch the Hubble Space Telescope, died on Dec. 25 at the age of 93, according to the Associated Press.

Roman was nicknamed “the mother of Hubble” for her work on the pioneering telescope, which launched in 1990. She joined NASA’s headquarters office soon after the agency’s founding in 1958. She was the first chief of astronomy, drawn to the offer of having the leeway to create such a pivotal department from scratch.