Roman’s planetary imaging system, the Coronagraph Instrument, also completed early checkout of its digital, electronic and mechanical systems after becoming operational earlier this month.

The tests are part of a multi-month commissioning process taking place as Roman travels approximately 1 million miles toward its destination, the second Lagrangian point, or L2.

Roman’s 300-megapixel camera is now operating in space

The Wide Field Instrument combines a very wide view of the sky with the sharp detail associated with space telescopes such as NASA’s Hubble Space Telescope. A single WFI image covers an area of the sky larger than the apparent size of the full Moon.

This combination of a wide field of view and high resolution will allow Roman to conduct extensive surveys of the universe. Scientists plan to use the observations to study planets beyond our solar system, investigate mysteries such as dark energy, and examine how matter is distributed throughout the universe.

Roman’s large, detailed data sets are also expected to support many additional scientific studies.

“After years of efforts to build and test the device on the ground, we can now confirm that it works in space,” said Josh Schrieder, wide-field instrument scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This is a major milestone for the Goddard team, the industry teams at BAE Systems and Teledyne, and the science center. There is much work to do, but we are on the path to breakthrough science.”

Cooling Roman’s infrared detectors

The equipment took 10 days to dry and undergo decontamination before engineers powered up the WFI. During that period, the detector was kept at a relatively warm temperature of -85 degrees Fahrenheit (-65 degrees Celsius) compared with its final operating temperature.

On the morning of September 11, the team turned off the instrument’s heater, allowing the WFI to cool to -225 degrees Fahrenheit (-143 degrees Celsius). At that temperature, engineers activated Roman’s 18 infrared detectors. Together, the detectors have a photosensitive area roughly the size of a laptop screen.

Later that night, the team turned on the instrument’s calibration system. The next morning, engineers began transmitting test data through the WFI and sending it back to Earth.

Engineers test Roman’s filters and focus

On Saturday evening, engineers focused on the element wheel, which contains filters, prisms, and other optical components. The system controls the wavelengths of light reaching the detector and can separate light from space objects into individual colors. This was the first time the mechanism had been tested without gravity.

By Sunday morning, the team was testing the WFI’s focusing mechanism. The system is critical for ensuring proper focus across the hundreds of thousands of images Roman is expected to take.

Throughout these tests, the detector continued cooling toward its final operating temperature of -300 degrees Fahrenheit (-183 degrees Celsius).

The results showed that the wide-field instrument was working as expected. Roman remains on track to release its first scientific images by early 2027.

Roman’s coronagraph completes initial testing

Roman’s Coronagraph Instrument is designed to demonstrate some of the most advanced technology ever sent into space to directly image planets orbiting other stars.

The instrument combines optics, masks, self-bending mirrors, and sensors designed to reduce the overwhelming glare of a star. By blocking that light, coronagraphs could allow scientists to detect the much weaker light reflected from nearby orbiting planets.

Scientists and engineers at Caltech/IPAC’s Coronagraph Command Center in Pasadena, California, verified that they could communicate with all major parts of the instrument. These systems include the software, thermal controls, mechanisms, cameras, and avionics that operate the coronagraph.

The test also confirmed that the ground team could remotely control various systems, including the movable mechanisms used to position masks, color filters, lenses, and prisms.

Preparing Roman’s coronagraph for science

Engineers also verified that the coronagraph’s thermal system was working properly and could warm the hardware to a relatively comfortable operating temperature of 72 degrees Fahrenheit (22 degrees Celsius).

With the exception of the detector, coronagraphs are designed to operate near room temperature. This approach makes the system easier to test while helping maintain the material properties required for a deformable mirror.

“Now that the test is complete, we’re decontaminating it,” said Eric Cady, an optical engineer leading the Roman Coronagraph commissioning effort at NASA’s Jet Propulsion Laboratory in Southern California. “We’re leaving the detector warm, so anything that gets on the surface, like water or trace chemicals, tends to move away from the surface. This will last 30 days, with occasional outages to perform other initial adjustment activities.”