Low-Earth-Orbit Constellation Phasing Using Miniaturized Low-Thrust Propulsion Systems

Many low-Earth-orbit constellations consist of multiple small satellites that are launched together in batches, and which make use of differential atmospheric drag for subsequent deployment and phasing. Depending on the initial altitude, this process can potentially take many months, or even years, to complete, and satellite altitudes can only ever be decreased, potentially affecting mission lifetimes. Miniaturized low-thrust propulsion systems are one option to achieve faster phasing and can additionally increase the constellation lifetime through drag compensation. Here, an analytical and numerical study comparing differential drag and low-thrust propulsion for constellation phasing is performed. Satellite electrical constraints associated with power generation and battery cycling life represent important factors that can decrease the performance of an onboard propulsion system. Despite these constraints, low-thrust propulsion can reduce total phasing times by an order of magnitude, or more, for altitudes in the range 300-700 km, while also increasing satellite flexibility and introducing a number of operational advantages. Remaining propellant can be used for drag compensation and collision avoidance maneuvers, while also reducing deorbiting times by many years.

Automated summary

This study compares differential drag and low-thrust propulsion for phasing in low-Earth-orbit constellations. Low-thrust propulsion can significantly reduce phasing times, increase constellation lifetime, and introduce operational advantages. Satellite electrical constraints may impact the performance of onboard propulsion systems and should be considered.