A Submillimeter Level Relative Navigation Technology for Spacecraft Formation Flying in Highly Elliptical Orbit

Area of Science:

• Aerospace Engineering
• Orbital Mechanics
• Precision Measurement

Background:

• Spacecraft formation flying (SFF) in highly elliptical orbits (HEO) is vital for space exploration.
• Precise guidance, navigation, and control (GNC), especially ranging, are critical for SFF mission success.

Purpose of the Study:

• Introduce and validate a novel K band microwave ranging (MWR) equipment for submillimeter-level precise ranging.
• Enable on-orbit verification of precise ranging technology for future HEO SFF missions.

Main Methods:

• Developed a K band MWR equipment utilizing a synchronous dual one-way ranging (DOWR) microwave phase accumulation system.
• Analyzed ranging error sources and developed relative orbit dynamic models for HEO formations with perturbations.
• Implemented an adaptive Kalman filter algorithm for SFF relative navigation, accounting for process noise uncertainty.

Main Results:

• Achieved tens of microns of ranging accuracy in a laboratory environment.
• Hardware-in-the-loop (HIL) simulations demonstrated range estimation errors under 35 μm and range rate errors under 8.5 μm/s.
• Validated the MWR system's promising accuracy for HEO formation mission applications.

Conclusions:

• The developed K band MWR equipment and adaptive Kalman filter provide submillimeter-level ranging accuracy.
• The system is well-suited for precise relative navigation in HEO SFF missions.
• This technology paves the way for enhanced GNC capabilities in future space exploration endeavors.