NGC Aerospace has completed a European Space Agency study that changes how satellites navigate in very low-Earth orbit (VLEO). Instead of fighting the atmosphere, the RAVELO program proves spacecraft can use aerodynamic friction to control their flight.
Flying in VLEO provides major hardware benefits. Telecommunications and Earth observation satellites experience lower signal latency and capture sharper images while requiring less payload mass. The main problem is severe atmospheric drag. This friction usually forces operators to burn through propellant or rely on heavy reaction wheels just to keep the satellite stable and pointed in the right direction.
The RAVELO (Robust Attitude and Orbit Control System for Very Low Earth Orbit) study solves this by treating the atmosphere as a control mechanism rather than a barrier. NGC engineers developed flight software that uses physical external control surfaces to steer the satellite. This setup delivers full three-axis control without needing traditional attitude control actuators for low-altitude missions. The system also manages momentum by using atmospheric torque to unload reaction wheels instead of relying on standard magnetic hardware.
The design goes further by incorporating air-breathing electric propulsion. This architecture captures sparse atmospheric particles and feeds them directly into an electric thruster to counteract drag.
“These innovations redefine the architecture of spacecraft control systems in VLEO and introduce new design trades between conventional and unconventional actuators,” the company stated in its release.
To make this work, the updated Attitude and Orbit Control System software includes new guidance rules like wind-relative flight and sun roll-steering. The system monitors the orbit autonomously and commands propulsion corrections without any ground support. Meanwhile, on-board algorithms constantly calculate air density and flow in real time.
The next steps involve maturing the aerodynamic algorithms and refining the air-breathing propulsion models. This work aims to get the system ready for commercial satellite constellations looking to operate closer to Earth.