In May of 2019, SpaceX launched a batch of 60 satellites into low Earth orbit (LEO) in the first of a series of launches designed to populate a “megaconstellation” of satellites called Starlink. A new study now examines how the presence of these satellites — and those of future megaconstellations — will impact optical astronomy.
A Prominent Population
The number of objects (>100 kg) in lower LEO by year; click to enlarge. Before Starlink’s launch, there were fewer than 400 objects in this range. Now, Starlink (cyan) has begun to dominate this naked-eye-visible population. [Adapted from McDowell 2020]With the goal of providing global internet access, Starlink and similar satellite megaconstellations sound like they should be a good thing. But this project, which is proposed to expand into a network of thousands of LEO satellites, has a drawback: these satellites are both large and orbit at low altitudes — which means they’re visible.
Right now, Starlink consists of 358 satellites orbiting in lower LEO (that’s below an altitude of 600 km); each of these satellites is 260 kg in mass and several meters across. If SpaceX launches the proposed number of satellites, there will eventually be more than 12,000 Starlink satellites ...