The TOLIMAN mission: A low-cost space telescope for high precision narrow-angle astrometry

TL;DR

The TOLIMAN mission proposes a low-cost, compact space telescope with innovative optical design to perform high-precision narrow-angle astrometry for detecting terrestrial exoplanets around Alpha Centauri AB, overcoming traditional size constraints.

Contribution

It introduces a novel optical and signal encoding architecture enabling microarcsecond astrometric precision with a small 12.5cm aperture telescope within a CubeSat platform.

Findings

Design concepts for extreme-precision optics are outlined.

The mission architecture supports microarcsecond astrometry in a compact form.

Construction of the CubeSat payload is underway.

Abstract

The TOLIMAN project is engaged with the construction, launch and operation of a low-cost space telescope of unorthodox optical design. Its primary science goal targets an exhaustive search for temperate-orbit rocky planets around either star in the alpha Centauri AB binary within our nearest-neighbor star system. Despite their favorable proximity and brightness, the detection of terrestrial exoplanets around such nearby Sun-like stars remains problematic for contemporary instrumental approaches. By performing narrow-angle astrometric monitoring of binary stars at extreme precision, any exoplanets will betray their presence by way of gravitationally-induced perturbations on the binary orbit. Recovery of this signal is challenging for it amounts to only a few microarcseconds of angular deflection (at best), and so is normally thought to require a large (meter-class) instrument. By implementing an innovative optical and signal encoding architecture, the TOLIMAN space telescope aims to recover such signals with a telescope aperture of only 12.5cm. This paper gives an overview of key features of the mission; in particular the concepts underlying the optics to enable image registration at the extreme levels of precision required. An outline is also provided, sketching further mission components and systems incorporated into the 16U CubeSat spacecraft bus in which the science payload is housed - all of which are now under construction.