Florian BIBOUD, Vinterstellar
Emil Vinterhav, Vinterstellar
Maria Hoflund, Vinterstellar
Florian BIBOUD, Flight Dynamicist, Vinterstellar AB
Geostationary satellites are indispensable for telecommunications, weather forecasting, and Earth observation due to their ability to maintain a fixed position relative to the Earth’s surface. However, sustaining this position requires constant station-keeping maneuvers to counteract perturbations caused by 3-body perturbation from the Moon and the Sun, gravitational irregularities, solar radiation pressure, and other environmental forces. Traditional station-keeping solutions rely heavily on adjustable thrusters and thrust-pointing mechanisms, which introduce significant complexity, cost, and mass, in addition to susceptibility to mechanical failures over time.
This research introduces a novel deterministic algorithm for fixed-thrust geostationary satellites that eliminate the need for adjustable thrusters while ensuring precise station-keeping performance. Although developed with electric propulsion in mind it be technically used for all kind of propulsion. The algorithm is also design-agnostic, meaning it can be implemented on a wide range of satellite platforms, making it particularly appealing for smallsat missions where simplicity and cost-efficiency are paramount.
The maneuver determination algorithm can be summarized as follows. The inputs to the algorithm are spacecraft design and required change in orbital elements and angular momentum. The design inputs build a system of equation based on thrusters direction and thrusters position with respect to the center of mass. This system of equations is completed by the required performance of the maneuver. By integrating the angular momentum into the system of equations we make a fully determine systems that enable us to have a deterministic solution and bypass thrusters orientation or pointing mechanism to take care of the angular momentum with requirement definition without any sacrifice in performance.
This algorithm is to be seen as a foundational building block in the maneuver planning scheme. It needs to be incorporated into a larger algorithm to be able to produce a full maneuvering scheme. An optimization layer could be added to insure fuel efficiency for the mission life time or a validation step could be added to ensure maneuvers avoid operational constraints such as avoiding burn during eclipse.
To demonstrate the algorithm’s effectiveness, a new maneuver scheme, named the “hopping maneuver,” has been developed. This strategy allows the satellite to remain within a geostationary box of 1.2*10-4 deg while keeping angular momentum below a 15 Nms threshold during the station-keeping cycle. The “hop” maneuver works by alternately adjusting eccentricity and angular momentum, balancing the effects of orbital perturbations. A typical cycle consists of two maneuvers: a “hop forth” and a “hop back,” both of which occur within a single day, ensuring that maneuvers do not overlap or interfere with each other. The size of the hop is a tunable parameter together with the spacecraft design, are customized to meet specific mission requirements, such as fuel constraints or mission lifetime.
The deterministic algorithm for fixed-thrust station-keeping offers a compelling alternative to traditional thruster pointing or thruster orientation based approaches. By simplifying satellite design, this approach aim to transform station-keeping strategies, particularly for smallsat missions where cost, mass, and operational simplicity are critical.
At the SmallSat 2025 Conference, attendees will gain insights into the development of this algorithm, its practical applications, and its potential to revolutionize station-keeping operations in the context of smallsat constellations. The algorithm’s ability to integrate seamlessly with existing and future propulsion technologies, as well as its scalability across diverse satellite platforms, makes it a compelling solution for a wide range of space mission scenarios.