1. Communication and Navigation System Doro Gracia Kazuya Suzuki Patrick Zeitouni

2. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture Mission Requirements  Provide adequate communication between: Rovers Emergency transfer vehicles Bases and waypoints  Provide adequate navigation capability for: lunar landers rovers along race route  Establish: communications and navigation infrastructure.

3. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture Comm Requirements & Issues  High data rates from rovers: 4 active HDTV channels 12 Mbps per rover  Continuous Rover coverage From lunar equator to pole trek  Rovers Limitations : Power limited, Earth-Moon distance at that data rate cannot be achieved Antenna Pointing accuracy a problem during race (bounce) Complex antennas like phased arrays can solve pointing problem, but are expensive, bulky, and are even more power inefficient

4. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture Lunar Com Options Trade Study  Looked at laser and radio frequencies (RF) communication Straight to Earth / Earth orbiting satellites Through Lunar orbiting satellites  Looked at surface towers  Chose LC to Earth Orbit for Bases & Waypoints  Chose RF to Lunar Orbit for Rovers

5. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture LC RF GEO Rover Com System GEO satellites either advanced TDRSS or commercial satellite equipped with optical head

6. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture  Rovers have a 0.3m antenna  Rovers communicate to Lunar orbit Adequate link margin Relaxed pointing requirement  Satellite Constellation 0.6m Antenna to Lunar surface, LC back to Earth 4 satellites in 2 repeating ground track orbits  Inclined (85~90) to service poles  Eccentric (0.6) to dwell longer in south pole  Satellite pairs spaced 180° apart in same orbit to provide handoff Rover Com System Details

7. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture Satellite Orbits

8. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture Rover Coverage

9. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture LCRF GEO Base & Waypoint Com System  Given their fixed locations, bases and waypoints communicate directly to Earth orbit using LC  GEO satellites either advanced TDRSS or commercial satellite equipped with optical head

10. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture Earth-Moon Phase Transport Com  Satellite based system with RF com capabilities for: Communications  between crew transport and Earth  between crew transport and L1 station depending on proximity < 55,000km. Use a 1m antenna (adequate dB margin) L1 Station

11. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture TV Programming  TV studios from Earth gateways provide live rover race feed (via satellites)  Continuous 24 hours a day coverage  Daily summaries with highlights of events  Pay-per-view provides: In-depth analysis behind the scenes And more

12. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture Navigation Mission Requirements  Provide navigation capabilities for the following: Lunar landings (manned & unmanned) Rovers Rescue missions

13. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture Available Options  Satellites  Towers  Beacons  Inertial systems  Image Terrain Navigation (landmarks)

14. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture  Landing navigation at bases Beacons (like existing airports)  Rover navigation Image terrain navigation for rovers  Backup guidance for rovers Inertial systems, recalibrated at waypoints Earth assistance Proposed Systems

15. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture  Emergency vehicle navigation Track the beacons on rovers  Beacons at Waypoints Assist in emergency or other landings  RF Buoys dropped by rovers Establish a route that future rovers can follow Assist in emergency landings Proposed Systems

16. 2-Dec-04 USC 2004 AME 557 Space Exploration Architecture Communication Link Budget