Exoplanet detection yield of a space-based Bracewell interferometer from small to medium satellites

Abstract

Space-based nulling interferometry is one of the most promising solutions to spectrally characterize the atmosphere of rocky exoplanets in the mid-infrared (3 to 20 μm). It provides both high angular resolution and starlight mitigation. This observing capability depends on several technologies. A CubeSat (up to 20 kg) or a medium satellite (up to a few hundreds of kg), using a Bracewell architecture on a single spacecraft could be an adequate technological precursor to a larger, flagship mission. Beyond technical challenges, the scientific return of such a small-scale mission needs to be assessed. We explore the exoplanet science cases for various missions (several satellite configurations and sizes). Based on physical parameters (diameter and wavelength) and thanks to a state-of-the-art planet population synthesis tool, the performance and the possible exoplanet detection yield of these configurations are presented. Without considering platform stability constraints, a CubeSat (baseline of b ≃ 1 m and pupils diameter of D ≃ 0.1 m) could detect ≃7 Jovian exoplanets, a small satellite (b ≃ 5 m∕D ≃ 0.25 m) ≃120 exoplanets, whereas a medium satellite (b ≃ 12.5 m∕D ≃ 0.5 m) could detect ∼250 exoplanets including 51 rocky planets within 20 pc. To complete our study, an analysis of the platform stability constraints (tip/tilt and optical path difference) is performed. Exoplanet studies impose very stringent requirements on both tip/tilt and OPD control.

Review and scientific prospects of high-contrast optical stellar interferometry

“…Another project to demonstrate a linear formation-flying astronomical interferometer in low Earth orbit is also currently under study. 77 To detect exoplanets, larger platforms are required as recently studied by Dandumont et al (2020). 78 Figure 4 shows the exoplanet yield analysis assuming the Kepler occurrence rate and assuming four different space-based nulling interferometer concepts (2-aperture fibered Bracewell).…”

“…77 To detect exoplanets, larger platforms are required as recently studied by Dandumont et al (2020). 78 Figure 4 shows the exoplanet yield analysis assuming the Kepler occurrence rate and assuming four different space-based nulling interferometer concepts (2-aperture fibered Bracewell). Two CubeSats (baseline: 0.5m/1.0m and apertures: 0.08m), an ESA PROBA-like mission (baseline: 5.0m and apertures: 0.25m), and the FKSI concept (baseline: 12.5m and apertures: 0.5m) were considered.…”

Performance study of interferometric small-sats to detect exoplanets: updated exoplanet yield and application to nearby exoplanets

“…11,12 In Ref. 13, our previous work, four configurations were considered, from small to medium satellites. The main objective was to develop our tools and present our first analyzes.…”

“…One of our conclusions is that small platforms are well suited to test and validate critical technological components needed for a larger mission as well as perform scientific observations. 13 In this paper, only small missions from Ref. 13 are considered: two CubeSats and one larger spacecraft of the size of the ESA PROBA-class family.…”

“…13 In this paper, only small missions from Ref. 13 are considered: two CubeSats and one larger spacecraft of the size of the ESA PROBA-class family. All of them are in a Bracewell configuration, e.g.…”