Enabling the emergence of mega-constellations
Constellations of hundreds of small, interconnected satellites are increasingly being deployed by defence bodies to provide real-time threat detection with global coverage, and by commercial entities to provide internet connectivity to remote and rural areas, environmental monitoring services and asset tracking. This report, which is the third in our sequence of three on mega-constellations, explores how the space industry is adapting to this challenge by adopting nimble, lower-cost design and manufacturing methodologies and reducing the cost of launching satellites into space. It also discusses why mega-constellations such as SpaceX’s Starlink are deploying optical communications links between satellites.
Proliferation of satellites
The shift from using a handful of complex satellites to constellations of hundreds of small, much less expensive satellites is driving a rapid increase in the number of satellites being launched each year. Until SpaceX started to launch its Starlink satellites into low Earth orbit (LEO) in 2019, the highest number of satellites launched in a single year was 143 in 1967. However, nearly 1,200 satellites were launched in 2020, with 1,778 satellites and spacecraft in 2021. This accelerated rate of satellite launches is expected to continue over the next decade. For this to happen, the cost of building and launching satellite platforms and their payloads needs to be substantially reduced so providing services via mega-constellations of LEO satellites is economically viable.
Interconnecting satellites with lasers
Constellations including SpaceX’s Starlink, Telesat’s Lightspeed and the US Space Defense Agency’s (SDA’s) system are deploying optical communications to connect satellites. These links enable data to pass between satellites at speeds comparable to fibre broadband connections and substantially improve the versatility and resilience of constellations. The report explores why intersatellite links are useful, the advantages of optical links over microwave ones and why the SDA is developing a standard to ensure interoperability between optical communications terminals from different vendors.
