Synopsis:
Navigation on the Moon or any foreign planet requires a land-based system that requires no backbone or infrastructure. Earth systems such as GPS are not available and are far too costly to implement. The dusthound company has created a phase 1 design for a lunar positioning system that can support multiple astronauts on a moon walk using an antenna array for direction of arrival estimation and programmable RFID tags in a breadcrumb trail. A continual wireless data link of 1 Mb/s between the lunar lander and each astronaut has also been incorporated into the design.
Design Overview:
An astronaut walking on the moon will have two sources of location information: RFID tags and a data stream from the lander. An array of 8 antennas on the lander will use phase offset and an iterative algorithm to estimate the angle of arrival of data coming from the astronaut. This location information will then be broadcast back to the astronaut through a 1Mb/sec wireless data link. RFID tags will also be dropped by the astronaut while they are walking. A tag reader/writer will write the astronaut's current location to a tag before it is dropped so that if an astronaut gets lost, they can interrogate the area for RFID tags and retrieve their current location. Tags will also send a unique identification number that will be recorded as they are dropped. This will allow past moon walks to be repeated and also allow for RFIDs to be left on the moon for future missions to reuse.
Project Summary:
| RFID | ||
|---|---|---|
| Range | 2.5 m | |
| Turn-On Power | -19 dB | |
| DOA Estimation | ||
| Accuracy | 0.05°/1.8 m | |
| Algorithm | Iterative Beamforming | |
| Astronaut Power | ||
| Consumption | 20 W maximum | |
| 1 W minimum | ||
| Source | 400 watt-hour EMU Battery | |
| Data Link | ||
| Carrier Frequency | 2.52 GHz | |
| Data Rate | 1 Mb/s | |
| Range | 2 km | |
| Modulation | 64-QAM | |
| Error Correction | Turbocoding | |
| Multiple Access | Code Division, Spread Spectrum | |
| Total Cost | $530,000.00 |