The future of astronomy with small satellites

Abstract

The number of small satellites has grown dramatically in the past decade from tens of satellites per year in the mid-2010s to a projection of tens of thousands in orbit by the mid-2020s. This presents both problems and opportunities for observational astronomy. Small satellites offer complementary cost-effective capabilities to both ground-based astronomy and larger space missions. Compared to ground-based astronomy, these advantages are not just in the accessibility of wavelength ranges where the Earth's atmosphere is opaque, but also in stable, high precision photometry, long-term monitoring and improved areal coverage. Astronomy has a long history of new observational parameter spaces leading to major discoveries. Here we discuss the potential for small satellites to explore new parameter spaces in astrophysics, drawing on examples from current and proposed missions, and spanning a wide range of science goals from binary stars, exoplanets and solar system science to the early Universe and fundamental physics. Main Astronomers tend towards wanting ever larger telescopes to collect more light, so the utility of small satellites is not always intuitive. Compared to ground facilities, space has many advantages. In the past the main deterrent to build more space instrumentation has been the prohibitive cost. However, over the past two decades the cost per kg of launches to low Earth orbit (LEO) has been dramatically reduced by factors of several with the entry of commercial operators (e.g. 1). Meanwhile, assembly lines offer the prospect of reducing costs associated with satellite design and manufacture for a fleet of identical or near-identical spacecraft. These developments create new opportunities for astronomers to exploit with creative approaches, despite their limitations of scale. The economic demand for internet bandwidth has led to commercial operators entering this domain, such as OneWeb and SpaceX. Can these developments also drive new mission concepts in astronomy and fundamental physics? This Perspective will mainly focus on 400-1500 km orbits, low masses (e.g. <50 kg), small physical sizes (e.g. 700x600x200 mm), and

The impact of satellite constellations on space as an ancestral global commons

“…The latest generation of low-cost small satellites, especially the picosatellites or CubeSats (mass ~0.1-1 kg), have already proven very useful for scientific research given how inexpensive and flexible they are (see ref. 1 in this issue). CubeSats have the added advantage of rapid construction with off-the-shelf components.…”

Feasibility study of an interferometric Small-Sat to study exoplanets

“…As described in the introduction, CubeSats are increasingly relevant for astronomy. 13,14,17 CubeSats are defined by their number of units. One unit, or 1U, corresponds to 0.1 × 0.1 × 0.1 m. In this article, we consider two Cubesat concepts, a 6U and a 12U.…”

“…12 With the cost-effective capabilities of small satellites (< 500 kg) and the emergence of CubeSats in the 2010's, it is now relevant to analyse this type of platform for astronomy. 13,14 In the exoplanet domain, CoRoT (Convection, Rotations et Transits planétaires), from CNES, was a pioneer in 2006 15 and opened the way to Kepler but these two missions were quite larger than S-class missions. TESS (Transiting Exoplanet Survey Satellite) or CHEOPS (CHaracterising ExOPlanets Satellite), both in duty, are smaller and can be considered as small satellites.…”

“…24,25 Astronomical CubeSats, smallsats, or projects will emerge more and more in the future. 13,14,17 In the present project, the idea is to focus first on a science case and then derive constraints on a small platform. The main goal is to know if a CubeSat or a slightly larger spacecraft can be both a scientific mission on its own and a precursor to a larger mission as LIFE.…”

In-orbit demonstration of an iodine electric propulsion system

“…We anticipate that these results will accelerate the adoption of alternative propellants within the space industry and demonstrate the potential of iodine for a wide range of space missions. For example, iodine enables substantial system miniaturization and simplification, which provides small satellites and satellite constellations with new capabilities for deployment, collision avoidance, end-of-life disposal and space exploration [10][11][12][13][14] .…”