Spacecraft and Instruments

Wide Field Instrument

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About The Wide Field Instrument

The Wide Field Instrument (WFI) is a 300-megapixel infrared camera that will allow scientists to look very far back in time. Seeing the universe in its early stages will help unravel how it has expanded throughout its history, which will hint at how it may continue to evolve.

Each Roman image will capture a patch of the sky bigger than the apparent size of a full Moon. Hubble’s widest exposures, taken with its Advanced Camera for Surveys, are nearly 100 times smaller. Over the first five years of observations, Roman will image over 50 times as much sky as Hubble covered in its first 30 years.

In order to know how the universe will end, we must know what has happened to it so far. This is just one mystery NASA's forthcoming Nancy Grace Roman Space Telescope will tackle as it explores the distant cosmos. The spacecraft's giant camera, the Wide Field Instrument (WFI), will be fundamental to this exploration.

The WFI has passed the preliminary design review, an important milestone for the mission. It means the WFI successfully met the design, schedule and budget requirements to advance to the next phase of development, where the team continues with the detailed design and fabrication of the flight hardware.

The team has flight-certified all of the 24 detectors for the WFI. These detectors will ultimately help provide the images Roman will take. With its large field of view, the WFI will provide a wealth of information in each image. This will dramatically reduce the amount of time needed to gather data, allowing scientists to conduct research that would otherwise be impractical.

The data gathered from the Wide Field Instrument will enable scientists to discover new and uniquely detailed information about planetary systems around other stars. It will map how matter is structured and distributed throughout the cosmos, which should ultimately allow scientists to discover the fate of the universe.

The WFI is designed to detect faint infrared light from across the universe. Infrared light is observed at wavelengths longer than the human eye can detect. The expansion of the universe stretches light emitted by distant galaxies, causing visible or ultraviolet light to appear as infrared by the time it reaches us. Such distant galaxies are difficult to observe from the ground because Earth’s atmosphere blocks some infrared wavelengths, and the upper atmosphere glows brightly enough to overwhelm light from these distant galaxies.

By going into space and using a Hubble-size telescope, the WFI will be sensitive enough to detect infrared light from farther than any previous telescope. This will help scientists capture a new view of the universe that could help solve some of its biggest mysteries, one of which is how the universe became the way it is now.

The WFI will allow scientists to peer very far back in time. Seeing the universe in its early stages will illuminate how the cosmos developed to its present condition, enabling scientists to predict how it will continue to evolve. Scientists will soon be able to explore some of the biggest mysteries in the cosmos thanks to the WFI’s wide field of view and precision optics.

Wide Field Surveys

The Wide Field Instrument will enable all of Roman’s surveys, which will explore:

Dark Energy

Dark Energy

Dark Energy

The Roman Space Telescope measurements will help illuminate the dark energy puzzle. With a better understanding of dark energy, we will have a better sense of the past and future evolution of the universe.

Dark Matter

Dark Matter

Dark Matter

Almost completely undetectable matter whose existence is implied to explain an excess of gravity measured in galaxies and galaxy clusters




Completing a census of Exoplanets to help answer new questions about the potential for life in the universe. This census makes use of a technique that can find exoplanets down to a mass only a few times that of the Moon.

Near Infrared

Near Infrared Surveys

Near Infrared

A vast astrophysics treasure trove allowing the exploration of everything from nearby stars to distant galaxies.

Roman’s surveys will also pinpoint large numbers of elusive cosmic objects, enhancing the science return from other observatories. While telescopes such as Hubble and the James Webb Space Telescope will provide excellent in-depth observations of some of the most intriguing objects in the cosmos, their narrow fields of view make it difficult to find many to study.

Roman will dramatically increase the sample size of objects like quasars – extremely bright cores of distant active galaxies – and supernova explosions by capturing hundreds of thousands of galaxies in each image. Scientists will be able to identify especially interesting regions and use other observatories to take a closer look.

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