Standalone GPS L1 C/A Receiver for Lunar Missions

Area of Science:

• Spacecraft Navigation
• Satellite Systems Engineering
• Deep Space Communications

Background:

• Global Navigation Satellite Systems (GNSS) are crucial for Earth-based positioning and timing.
• Spacecraft increasingly utilize GNSS for navigation in various Earth orbits (LEO, MEO, GEO) and beyond.
• The Earth-Moon transfer environment presents significant challenges for GNSS signal reception due to weaker signals and high dynamics.

Purpose of the Study:

• To introduce and validate the "WeakHEO" receiver, a proof-of-concept GPS L1 C/A receiver engineered for lunar missions.
• To assess the performance of the WeakHEO receiver in simulated segments of an Earth-Moon Transfer Orbit (MTO).
• To demonstrate the practical application of current technology for GNSS-based navigation in MTO environments.

Main Methods:

• Development of the "WeakHEO" receiver, a specialized GPS L1 C/A receiver.
• Hardware-in-the-loop simulation using a GNSS Spirent simulator to collect real-time observations.
• Processing of collected GNSS data through a navigation module to evaluate performance.

Main Results:

• The WeakHEO receiver successfully collected hardware-in-the-loop observations in simulated MTO conditions.
• Navigation module processing confirmed the feasibility of utilizing GNSS signals within these challenging orbital segments.
• The study validates the potential for GNSS to support lunar mission navigation.

Conclusions:

• The "WeakHEO" receiver represents a viable technological solution for GNSS-based navigation during lunar missions.
• Current technology is sufficient to exploit GNSS signals effectively for navigation in Earth-Moon Transfer Orbits.
• This research paves the way for enhanced spacecraft autonomy and navigation capabilities in deep space.