Set to launch on Sunday, Aug. 30, NASA’s Nancy Grace Roman Space Telescope will empower astronomers to explore vast regions of the cosmos and settle essential questions in the areas of dark energy, dark matter, planets outside our solar system, and the formation and growth of galaxies over cosmic time. Key contributions to Roman’s mission made by researchers at NASA’s Ames Research Center in California’s Silicon Valley will advance Roman’s science using the center’s facilities, expertise, and innovations.

Tools to predict, remove glare

Roman’s main camera, the Wide Field Instrument, will capture expansive high-resolution pictures of the universe in optical and near-infrared light. These unprecedented images will enable astronomers to decode some of the deepest mysteries of the cosmos.

Forms of glare that Roman’s camera collects diminish image quality and thereby reduce the ability of astronomers to characterize certain cosmic structures. Innovative software developed by a team at NASA Ames, with collaborators at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and IPAC/Caltech in Pasadena, California, will improve Roman’s images and optimize observing plans. Called ROSALIA (Roman Sky Analyst for Low Surface Brightness Imaging and Astronomy), the software predicts and removes unwanted light from astronomical images captured by Roman’s Wide Field Instrument.

Contaminating stray light occurs when photons scatter inside the telescope’s optical system. Resulting light glints can produce deceptive image artifacts that mimic the appearance of real planets or nebulae. The ROSALIA software will allow astronomers to adjust their observation plans to limit glints from contaminating science targets in Roman’s images.

In addition to bright glints, stray light can also appear as a diffuse background. This form of stray light interferes with observations of the darkest regions of the universe, which is critical to understanding how large structures in the universe were formed.

Another major contributor to obscuring background light is produced by nature itself: zodiacal light. Zodiacal emission originates from the scattering of sunlight by interplanetary dust particles in our solar system. The ROSALIA software predicts and strips away background contamination, including zodiacal and stray light from images, exposing the faint, diffuse emissions at galaxy edges where cosmic evolutionary histories are hidden.

New ‘multi-star’ tech to see exoplanets

The Roman Coronagraph Instrument is one of two instruments flying on Roman. It will demonstrate the most advanced technologies ever flown in space for directly imaging planets around other stars. The Roman Coronagraph uses a series of masks and mirrors, including two deformable mirrors, to suppress starlight. By precisely controlling the shape of the deformable mirrors, it creates a “dark zone” around the star where observers can see the faint reflected light from orbiting planets.

The baseline operating mode of the Roman Coronagraph Instrument supports observation of exoplanets only in single star systems, as current coronagraph instruments cannot typically suppress the additional contaminating starlight in multi-star systems, such as binary star systems.

Our solar system has a single star, the Sun. But roughly half of Sun-like stars are in multi-star systems. Having the ability to directly image exoplanets in multi-star systems will increase the likelihood of detecting life beyond our solar system and will expand our knowledge about how exoplanets form and evolve, since there are major differences in how those processes unfold in single star versus multi-star systems. Eliminating overlapping glares from multiple stars is the key challenge that must be overcome to image planets in such systems.

Researchers at NASA Ames are meeting that challenge with an innovative technology called Multi-Star Wavefront Control (MSWC). This technology includes custom light-blocking masks and accompanying software designed to suppress the light from multiple stars and reveal hidden exoplanets. Through a collaboration with NASA’s Jet Propulsion Laboratory in Southern California, the MSWC masks are included on the Roman Coronagraph’s flight instrument as an added capability beyond Roman’s baseline observation modes. They could be used if additional observation time is granted to the coronagraph team after the primary technology demonstration phase is completed. 

The nearest star system to our solar system, Alpha Centauri, is one of the nearest multi-star systems to Earth,  at only four light-years away. This triple-star system contains a binary of Sun-like stars – Alpha Centauri AB – orbited by a much smaller and dimmer star – Proxima Centauri. Although no exoplanets are confirmed around the Sun-like stars in this system, a planet candidate has been identified by NASA’s James Webb Space Telescope in the habitable zone of Alpha Centauri A. Researchers, including the Ames MSWC team, are working to develop the capabilities needed to observe this system.  

NASA Ames also provides leadership and support for the hardware working group as part of the Roman Coronagraph Participation Program. This program allows international teams of researchers to enable additional capabilities to the Roman Coronagraph beyond its baseline modes; this includes the multi-star modes being developed at NASA Ames that use different masks beyond the baseline or new wavefront control and sensing algorithms.

Close-up view of four of the Roman Coronagraph’s optical masks. The bottom-right mask, shaped like a six-petaled flower, is designed to suppress the light from multiple stars and reveal hidden exoplanets.

NASA JPL/Chris Gunn

Advanced supercomputing

Experts at NASA’s Advanced Supercomputing Division at Ames are advancing Roman’s science by bringing extensive experience in data pipelines and mission operations to provide advice and guidance to the Roman project through key mission development phases. This ensures reliable performance of ground-based systems and operations so that science data processing is efficient and the quality and integrity of the resulting science data products is high.

NASA Advanced Supercomputing researchers collaborated with the Ames MSWC team to develop high-performance computing tools for multi-star wavefront control simulations and to conduct studies to assess the feasibility of the MSWC technique.

Quelle: NASA

+++

9 Things to Know About NASA’s Nancy Grace Roman Space Telescope

NASA’s Nancy Grace Roman Space Telescope is set to launch at 7:26 a.m. EDT on Sunday, Aug. 30. While you wait to watch the launch, brush up on some key facts about this wide-view mission.

• 01

  The mission is named after NASA’s first chief astronomer, Dr. Nancy Grace Roman.

  Roman is named after Dr. Nancy Grace Roman (1925–2018), NASA’s first chief of astronomy. She championed space-based observatories that could study the universe above Earth’s hazy atmosphere while making their data broadly available to the scientific community.
   
  While she’s known as the “mother” of the Hubble Space Telescope, Roman played an even broader role as the driving force behind NASA’s entire Great Observatories program, which included Hubble along with the Chandra X-ray Observatory and the retired Compton Gamma Ray Observatory and Spitzer Space Telescope.
   
  Her vision and leadership helped establish NASA as a world-class scientific institution and laid the foundation for generations of space telescopes that continue to expand humanity’s understanding of the cosmos.

• 02

  Roman will transform our view of the cosmos by showing us the bigger picture.

  Roman will pair a large field of view with crisp infrared vision to scan vast, deep swaths of sky. This flagship mission is designed to help astronomers explore dark matter, dark energy, and planets outside our solar system, called exoplanets.
   
  Since each of Roman’s surveys will sample such a large volume of the cosmos, the mission will also offer practically limitless opportunities for astronomers to conduct a broad range of additional science. From objects in our outer solar system and exploding stars to growing black holes and galaxies by the billions, very little will be beyond Roman’s reach. Roman’s data will be made public as soon as it’s processed, allowing many teams to analyze it simultaneously.

• 03

  The observatory will journey a million miles to join Webb at Lagrange point 2.

  Roman will orbit 1 million miles away at the second Sun-Earth Lagrange point (L2), the same location as NASA’s James Webb Space Telescope. At L2, gravity from the Sun and Earth works together with an object’s motion around the Sun to hold it roughly in place. This balance will give Roman a relatively steady orbit without using much fuel.
   
  Like Webb, Roman will trace out a large orbit around the actual L2 point — much larger than the Moon’s orbit around Earth — and the two will easily be kept far apart.

• 04

  The spacecraft carries the names of more than a million people.

  This summer, everyone was invited to submit their name to be added to a memory card attached to a plaque on the Roman spacecraft. More than 1.3 million people did so and will have their names carried all the way to L2.

• 05

  Roman will scan the skies for at least five years.

  Roman will have a primary mission lifetime of five years and is designed to support an additional five-year extended mission. Fuel is expected to be the mission’s life-limiting resource, and while NASA does not currently have an ability to service observatories at L2, Roman is designed to be refuelable.

• 06

  Two instruments will enable myriad discoveries.

  The observatory’s Wide Field Instrument is a 300-megapixel infrared camera that will give Roman the same sharpness (angular resolution) as Hubble but with a field of view at least 100 times larger. Using this instrument, each Roman image will capture a patch of the sky about 1.5 times bigger than the apparent size of a full Moon.
   
  Roman’s Coronagraph Instrument is designed to demonstrate the most advanced technologies ever flown in space for directly imaging planets around other stars. It will block the glare from stars and make it possible for scientists to see the faint reflected light from planets in orbit around them, revealing giant worlds that are older, colder, and in closer orbits than the hot, young super-Jupiters direct imaging has mainly revealed so far.

• 07

  Roman joins an international cohort of teamworking telescopes.

  Roman will work in tandem with many other NASA-led and international missions to provide the most complete view of our universe yet. Roman’s large panoramas will uncover interesting targets that Hubble could follow up on using infrared, visible, and ultraviolet light to offer a more comprehensive view. NASA’s James Webb Space Telescope can then use its larger mirror and more powerful vision to deliver even more detailed, ultra-sharp observations. And Roman can view regions around objects Hubble or Webb observe to offer context.
   
  Euclid, an ESA (European Space Agency) mission with key contributions from NASA, will observe a larger area of the sky than Roman, though with less detail. Since their survey areas will overlap, scientists can use Roman’s higher-quality data to apply corrections to Euclid’s, then extend these refinements over Euclid’s much larger area.
   
  Scientists can also pair Roman’s infrared data with visible-light observations from the ground-based Vera C. Rubin Observatory, a National Science Foundation–Department of Energy collaboration. That will allow astronomers to inch closer to achieving Roman-like quality over Rubin’s much greater sky coverage.
   
  By showcasing technology to directly photograph Jupiter-like exoplanets, Roman will also provide a crucial stepping stone for NASA’s Habitable Worlds Observatory concept, a flagship space telescope that would be designed to photograph Earth-like planets in other solar systems for the first time ever.

• 08

  Watch the Roman launch live from anywhere.

  NASA will stream this event live through a variety of platforms. Learn where to watch online: nasa.gov/live. The launch broadcast will continue until approximately one hour past launch to follow the first several critical milestones post-launch.

•