Twinkle: a small satellite spectroscopy mission for the next phase of exoplanet science

Abstract

With a focus on off-the-shelf components, Twinkle is the first in a series of cost competitive small satellites managed and financed by Blue Skies Space Ltd. The satellite is based on a high-heritage Airbus platform that will carry a 0.45 m telescope and a spectrometer which will provide simultaneous wavelength coverage from 0.5-4.5 𝜇m. The spacecraft prime is Airbus Stevenage while the telescope is being developed by Airbus Toulouse and the spectrometer by ABB Canada. Scheduled to begin scientific operations in 2025, Twinkle will sit in a thermally-stable, sun-synchronous, low-Earth orbit. The mission has a designed operation lifetime of at least seven years and, during the first three years of operation, will conduct two large-scale survey programmes: one focused on Solar System objects and the other dedicated to extrasolar targets. Here we present an overview of the architecture of the mission, refinements in the design approach, and some of the key science themes of the extrasolar survey.

ExoRad 2.0: The generic point source radiometric model

“…The software has been extensively validated against the Ariel radiometric model ArielRad (Mugnai et al, 2020), the time domain simulator ExoSim (Sarkar et al, 2021) and custom simulations performed by the Ariel consortium. ExoRad 2.0 is now used not only by the Ariel consortium but also by other missions, such as the balloon-borne NASA EXCITE mission (Nagler et al, 2022), the space telescope Twinkle (Stotesbury et al, 2022), and an adaptation for the James Webb Space Telescope (Gardner et al, 2006) is under preparation. Such JWST adaptation has been tested against the JWST Exposure Time Calculator (Pontoppidan et al, 2016) and returned consistent results, providing a validation of the code against a working system.…”