U of A to build instruments for new space telescope

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In a basement laboratory at Steward Observatory, astronomers don bunny suits and grounded gloves, slip behind translucent vinyl curtains, and approach a gleaming vacuum chamber. Inside, mirrors and sensors are arrayed on an optical bench, to be tested under space-like conditions – the same instruments that will someday be able to block starlight to reveal distant worlds that are nearly a billion times dimmer than the stars they orbit.

For years, this testbed served as a proving ground for technologies that could possibly go into space. Now, the University of Arizona will use it to  develop two of the three instruments aboard Lazuli, a three-meter space telescope that will push the boundaries of exoplanet imaging and join three ground-based observatories as part of the newly announced Eric and Wendy Schmidt Observatory System, a project of Schmidt Sciences, a philanthropic organization built by investor Wendy Schmidt and former Google CEO Eric Schmidt. The Schmidt Observatory System is designed to accelerate scientific discovery by expanding access to high-quality ground and space-based observational capabilities and uniting rapid development cycles with open data and shared scientific tools.

A rendering of the Lazuli Space Telescope observing from its orbit in space.

Schmidt Sciences, LLC

"We believe major discoveries happen when new capabilities are placed in the hands of creative scientists," said Arpita Roy, who leads the Astrophysics Center at Schmidt Sciences. "Our goal is to shorten the distance between technological possibility and scientific impact – and to create an ecosystem where ambitious ideas can move quickly from concept to collecting photons."

The Lazuli system is aiming to be completed by 2029. "This project represents a convergence of the U of A's decades of expertise in building space instruments and adaptive optics," said Ewan Douglas, associate professor at Steward Observatory and principal investigator of both instruments.

The two U of A-built instruments – the ExtraSolar Coronagraph (ESC) and the Widefield Context Camera (WCC) – will work in tandem aboard Lazuli to explore a range of astrophysical questions. The coronagraph will image giant planets and dust disks around nearby stars, providing improvements of several orders of magnitude over the Hubble Space Telescope's sensitivity. The WCC is a general-purpose astrophysics instrument with an array of sensors and filters for high-resolution astrophysics studies.

Taking adaptive optics to space

At the heart of the coronagraph, according to Douglas, is a simple but innovative concept: taking adaptive optics to space. 

"On the ground, adaptive optics systems use deformable mirrors to compensate for atmospheric turbulence – the 'twinkle' that blurs astronomical observations," he said. "In space, there's no atmosphere to contend with, but telescopes must contend with optical imperfections in their mirrors and changes caused by temperature changes."

By continuously correcting these nanometer-level errors, Douglas says the instrument will "dig dark holes" – regions where optical errors are eliminated, allowing astronomers to detect planets a billion times dimmer than their host stars.

This capability is expected to enable Lazuli to detect reflected light from Neptune-sized planets orbiting nearby stars.

"With Lazuli, we're also testing a lot of technologies the community is interested in, which may help speed up the development of missions like NASA's Nancy Grace Roman Space Telescope and the planned Habitable World Observatory," Douglas said. "The intention is for these upcoming missions all to inform each other, and for the science to be synergistic."

The project embodies a new philosophy in space instrumentation: building capable science instruments quickly by using commercial, off-the-shelf components rather than spending decades developing custom hardware. The WCC exemplifies this approach – it's an array of detectors with different filters, with no moving parts like the filter wheels common on space observatories like Hubble or the James Webb Space Telescope.

Advances in computing allow the instruments to perform real-time data analysis and wavefront control in orbit – a capability that will allow Lazuli to optimize observations in ways that weren't possible for more traditional space missions, which often must finalize decisions about computers as much as a decade before launch. 

"This approach allows us to use software already developed by scientists and students at U of A for similar ground-based instruments," said Jared Males, associate astronomer at Steward Observatory, "letting us move quickly with well-proven software."

Commitment to open science

The team is committed to open science, planning to share all software and data publicly so that future projects can benefit from lessons learned. This openness, Douglas emphasized, will help accelerate the pace of innovation for future missions.

The testbed facility in the U of A Space Astrophysics Lab and Steward's Center for Adaptive Optics – one of the few places in the world where coronagraphs can be tested in vacuum conditions – has enabled the team to speed up research and development, studying and publishing new approaches that will now help optimize the Lazuli Space Telescope. The instruments are being built by a team spanning multiple colleges at U of A, including Wyant College of Optical Sciences, College of Engineering and College of Science. Elizabeth Fucetola and Catherine Merrill, Steward Observatory's team of Space Telescope Program Directors, manage the ESC and WCC, respectively, while Douglas coordinates the overall instrumentation project.

"We're bringing in a very distributed team, working with folks from all different stages of their careers, ranging from students through senior engineers," Fucetola said. "I think that sets us apart from projects that you see in industry."

Schmidt Sciences is funding the U of A team to deliver both instruments in under three years – a swift pace made possible by years of groundwork laid through the Technology and Research Initiative Fundsupport and private donations.

For Saraswathi Subramanian, an astronomy postdoctoral research fellow who is developing instrumentation for the project, Lazuli will be her first space-based project.

"In addition to working on an instrument that will actually fly in space, it's especially exciting that the mission is expected to launch within a couple of years and we'll get to see the results of our work," she said.