Nasa is about to launch a space observatory that could help settle some of the biggest mysteries in modern astronomy. The Nancy Grace Roman space telescope will study how the universe began, what it is made of and how it has evolved over time.

The observatory is named after Nasa’s first chief of astronomy and its first female executive. Nancy Grace Roman, who died in 2018 aged 93, made important contributions to our understanding of stars and played a crucial role in shaping Nasa’s space-based astronomy programme.

The telescope is undergoing final preparations ahead of a launch set to take place from Florida’s Kennedy Space Center in late August. It is eight months ahead of its original schedule, and under budget – a rare feat for a Nasa flagship mission.

Unlike the James Webb space telescope, which is designed to look at individual objects in extraordinary detail, Roman is built to survey the sky at scale. It will take in vast areas of the cosmos, allowing astronomers to build up a much broader picture of the universe and how it changes.

Roman has an unusual history. It began life as a “spare” spy satellite, donated to Nasa by the US government agency responsible for gathering intelligence from space.

Roman carries two main instruments, added by Nasa. These are the wide field instrument and the coronagraph. The wide field instrument will detect infrared light coming from the universe. Infrared light has wavelengths that are slightly longer than those of visible light. This allows the instrument to see through cosmic dust and look deeper into the cosmos.

Its field of view – how much sky it sees when pointed in a given direction – is about 100 times that of the Hubble space........

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