Optical Design Pathways to Fluidic Space-Assembled Reflectors & Dual-Configuration Spectrographs for Characterizing Exo-Earths
Fluidic Telescopes – We present a conceptual framework for optically designing space-assembled telescopes whose primary mirror is formed in situ via the enabling, scale-invariant technology of fluidic shaping.
In-space assembly of optical reflectors can solve light-gathering aperture scaling, which currently limits space-borne optical telescopes. Our compass reduces the top-level optical design trade to three types of avenues—a fluidic pathway, a legacy one building upon the James Webb Space Telescope, and hybrid solutions—with a focus on exo-Earths.
A primarily fluidic pathway leads, in the first place, to a post-prime-focus architecture. We apply this configuration to propose the tentative optical design for a ~1-m technology demonstrator and pathfinder for fluidic-telescope apertures scaling up to many tens of meters in diameter.
Dual-Configuration Spectrographs | The Habitable Worlds Observatory (HWO) will be the first mission equipped for the high-contrast direct imaging and remote spectral characterization, in reflected starlight, of exo-Earths in our galactic neighborhood. We present a novel concept for a compact, dual-configuration HWO spectrograph tailored for a broad wavelength range covering at least 600–1000 nm.
Our design can interchange dispersive elements via a slider mechanism while preserving the rest of the optical path, enabling both a spectral resolving power R~140 integral-field spectrograph and a single- or multi-object spectrograph with R on the order of 103.
Although R~140 is near-optimal for the O2 absorption A-band around 760 nm, higher values of R can be utilized with spectral cross-correlation matched-filter techniques to enhance, e.g., HWO’s atmospheric characterization capabilities.
Enrico Biancalani, Edward Balaban, Ruslan Belikov, Eduardo Bendek, Valeri Frumkin, Israel Gabay, Guangjun Gao, Qian Gong, Christine Gregg, Tyler Groff, Joseph Howard, Omer Luria, Michael McElwain, Lee Mundy, Rachel Ticknor, Sylvain Veilleux, Neil Zimmerman
Comments: Submitted for publication as part of the proceedings for the HWO25 symposium
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2510.02479 [astro-ph.IM] (or arXiv:2510.02479v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2510.02479
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Submission history
From: Enrico Biancalani
[v1] Thu, 2 Oct 2025 18:36:05 UTC (2,868 KB)
https://arxiv.org/abs/2510.02479
Astrobiology, Astronomy,
