A Thousand Earths: A Very Large Aperture, Ultralight Space Telescope Array for Atmospheric Biosignature Surveys

Abstract

An outstanding, multi-disciplinary goal of modern science is the study of the diversity of potentially Earth-like planets and the search for life in them. This goal requires a bold new generation of space telescopes, but even the most ambitious designs yet hope to characterize several dozen potentially habitable planets. Such a sample may be too small to truly understand the complexity of exo-earths. We describe here a notional concept for a novel space observatory designed to characterize 1,000 transiting exo-earth candidates. The Nautilus concept is based on an array of inflatable spacecraft carrying very large diameter (8.5m), very low-weight, multi-order diffractive optical elements (MODE lenses) as light-collecting elements. The mirrors typical to current space telescopes are replaced by MODE lenses with a 10 times lighter areal density that are 100 times less sensitive to misalignments, enabling light-weight structure. MODE lenses can be cost-effectively replicated through molding. The Nautilus mission concept has a potential to greatly reduce fabrication and launch costs, and mission risks compared to the current space telescope paradigm through replicated components and identical, light-weight unit telescopes. Nautilus is designed to survey transiting exo-earths for biosignatures up to a distance of 300 pc, enabling a rigorous statistical exploration of the frequency and properties of life-bearing planets and the diversity of exo-earths.

Disruptive space telescope concepts, designs, and developments: OASIS and Nautilus -INVITED

“…Due to the compact launch configuration, multiple Nautilus units could be launched simultaneously in next-generation rocket fairings (right). [3,4] 3 Technology developments…”

“…In visible and near-infrared astronomy, an outstanding goal is to study the diversity of potentially Earth-like planets. Nautilus is a space telescope concept that builds on an engineered material diffractive-transmissive optical element [3,4]. The primary mirrors typical of current space telescopes are replaced by an ~8.5-meter MODE (multi-order diffractive engineered) lens with 10 times lower areal density, thereby enabling a lightweight structure.…”

Vertically Resolved Magma Ocean–Protoatmosphere Evolution: H2, H2O, CO2, CH4, CO, O2, and N2as Primary Absorbers

“…For instance, astrochemical studies of ever‐higher precision deliver clues to the origins of major atmophile elements during the main planet formation era (Bergner et al., 2020; van ’t Hoff et al., 2020). Ongoing (Dreizler et al., 2020; Ricker et al., 2015) and future (Apai et al., 2019; Gaudi et al., 2020; Meixner et al., 2019; Quanz et al., 2019; The LUVOIR Team, 2019) exoplanet surveys will reveal statistically meaningful characteristics of Earth‐sized planets on temperate orbits. Having so far only glimpsed the richness and diversity of the exoplanet census, statistical evaluation of basic physical properties—such as mass, radius, and atmospheric features—teach us that individual rocky planets differ substantially from one another and from the terrestrial planets of the Solar System (Jontof‐Hutter, 2019; Owen, 2019; Pierrehumbert & Hammond, 2019).…”

Advances in optical engineering for future telescopes

“…A pinwheel aperture segmentation is a promising approach which obtains a point spread function (PSF) with enhanced axial symmetry. This is modeled using Fraunhofer diffraction theory with the Pythonbased POPPY simulation tool 14 .…”