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

## TL;DR

The paper proposes a novel large-scale space telescope array using lightweight, inflatable optical elements to survey 1,000 potentially habitable exoplanets for biosignatures, significantly advancing the scope of exoplanet characterization.

## Contribution

It introduces the Nautilus concept, a large array of inflatable spacecraft with lightweight MODE lenses for extensive exo-earth biosignature surveys, reducing costs and risks compared to traditional telescopes.

## Key findings

- Potential to characterize 1,000 exo-earth candidates.
- Significantly lighter and cost-effective design.
- Enables statistical analysis of life-bearing planets.

## 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.