What is a Proliferated Low Earth Orbit (pLEO) Constellation?

A Proliferated Low Earth Orbit (pLEO) constellation is a large-scale collection of hundreds or potentially thousands of small LEO satellites. These LEO satellites orbit at altitudes of less than 2000 km. pLEO constellations were developed for resilient global network coverage by providing network capabilities even if some of the satellites in the network malfunctioned or were damaged.

The advancement of satellite technology over recent years has enabled satellites to get more compact while improving performance specifications. New-gen satellites can support multiple wireless technologies like GNSS, cellular etc. more efficiently which eliminates the need to launch multiple types of satellites for each type of network. Moreover, the compactness of these satellites allows the deployment of multiple satellites in a single trip to space which would reduce the cost of launching satellites significantly. These factors combined with the increasing demand for global connectivity has reduced the cost of development of large-scale satellite networks and have made pLEO constellations feasible and more accessible.

When a constellation of hundreds or thousands of pLEO satellites would be deployed, it would provide coverage across the earth. Several satellites of such constellations would orbit close to each other which would result in multiple satellites covering the same area. Hence, pLEO constellations would provide access to network connectivity anywhere on the Earth’s surface creating a truly global connectivity solution. Coverage from multiple satellites also ensures that connectivity is not hindered even if some satellites malfunction or are damaged, thus providing robustness to the network. Being made of LEO satellites orbiting close to the earth’s surface, these constellations would be able to provide fast data transfer rates with minimal latency compared to other types of constellations (MEO, GEO etc) and hence cater to the growing demand for global high-speed cellular and internet connectivity. Such network capabilities will be very useful in a variety of applications like remote tracking and management, live streaming services, providing global internet connectivity, military and defense communication scenarios etc. 

pLEO constellations also present unique challenges like the requirement of a complex mesh network able to dynamically recover from active counter space, cyber-security, and environmental threats while providing uninterrupted data-center-like processing. Management of resource utilization, task migration, data fusion, software and firmware updates and distribution of intelligence across the constellation requires complex integration and autonomy. Mission execution requires secure communication between the pLEO constellation and all consumers. pLEO constellations also pose the problem of congesting the Earth’s atmosphere. The large numbers of pLEO satellites will exponentially increase the number of collisions in space and as a result, increase the amount of space debris too.

OneWeb, SpaceX’s Starlink, Lightspeed from Telesat, Amazon’s Kuiper and Blackjack program of the Department of Defense, SDA and DARPA are all working on pLEO constellations. The Starlink constellation currently has around 2000 satellites in orbit and aims to launch over 11,000 satellites in total. Starlink has been developed to provide global internet connectivity for exceptionally cheap prices aiming to make the internet accessible to as many people as possible. Amazon has plans to deploy around 3236 Kuiper satellites and Telesat’s Lightspeed is planned to have around 300 satellites. OneWeb also aims to provide global internet connectivity and also serve as a military & defense communication network.