U of A to build instruments for deep space telescope
Associate professor of aerospace and mechanical engineering Ewan Douglas leads an interdisciplinary group of researchers to build two out of three instruments for the Lazuli telescope.
Optical science postdoctoral researcher Hyukmo Kang (left) and graduate student Solvay Blomquist align space telescope optics in the U of A's Applied Research building.
Schmidt Sciences/Chris Gunn Photo
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 space-bound technologies. 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.
Lazuli will join three ground-based observatories as part of the Eric and Wendy Schmidt Observatory System, announced recently. Schmidt Sciences, a philanthropic organization founded by investor Wendy Schmidt and former Google CEO Eric Schmidt, runs the project.
A rendering of the Lazuli Space Telescope orbiting in space.
Schmidt Sciences, LLC
The Schmidt Observatory System is designed to accelerate scientific discovery by expanding access to high-quality ground and space-based observational capabilities.
"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 with a joint appointment in the Department of Aerospace and Mechanical Engineering.
Douglas, also an associate professor of astronomy, serves as principal investigator for both instruments.
Making discoveries at a distance
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, improving sensitivity by several orders of magnitude greater than the Hubble Space Telescope. The WCC is a general-purpose astrophysics instrument with an array of sensors and filters for high-resolution astrophysics studies.
At the heart of the coronagraph, according to Douglas, is a simple but novel concept: taking adaptive optics into 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."
The instrument will continuously correct these nanometer-level errors and "dig dark holes" – regions where optical errors are eliminated – allowing astronomers to detect planets a billion times dimmer than their host stars.
Thanks to this capability, Lazuli will 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 team is committed to open science, planning to share all software and data publicly so future projects can learn from the work.
This openness, Douglas said, will help accelerate the pace of development 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 – allowed the team to speed up research and development, studying and publishing new approaches that will now help optimize the Lazuli Space Telescope.
A team spanning multiple colleges at U of A is building the instruments, including Wyant College of Optical Sciences, the College of Engineering and the 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."
