A Linear Formation Flying Astronomical Interferometer in Low Earth Orbit

TL;DR

This paper explores the feasibility of a small-scale formation flying interferometric array in Low Earth Orbit to advance space interferometry technology and enable detailed astrophysical measurements, especially of exoplanets.

Contribution

It proposes a novel system architecture and demonstrates through orbital simulations that such an array can be stable and capable of performing interferometry with minimal delta-v and simple thruster configurations.

Findings

Array stability with < 50m/s/year delta-v

Orbital configurations allow significant sky coverage

Feasibility of small-scale space interferometry demonstrated

Abstract

Space interferometry is the inevitable endpoint of high angular resolution astrophysics, and a key technology that can be leveraged to analyse exoplanet formation and atmospheres with exceptional detail. However, the anticipated cost of large missions such as Darwin and TPF-I, and inadequate technology readiness levels have resulted in limited developments since the late 2000s. Here, we present a feasibility study into a small scale formation flying interferometric array in Low Earth Orbit, that will aim to prove the technical concepts involved with space interferometry while still making unique astrophysical measurements. We will detail the proposed system architecture and metrology system, as well as present orbital simulations that show that the array should be stable enough to perform interferometry with < 50m/s/year delta-v and one thruster per spacecraft. We also conduct observability simulations to identify which parts of the sky are visible for a given orbital configuration. We conclude with optimism that this design is achievable, but a more detailed control simulation factoring in a demonstrated metrology system is the next step to demonstrate full mission feasibility.