Radio Science (RS) using the Ultra Stable Oscillator (USO)
Objectives:
Atmosphere
- Determine Profiles of Refractive Index, Number Density,
Temperature and Pressure at up to 20 meters Vertical Resolution
for the Lowest Few Scale Heights at High Latitudes in Both
Hemispheres on a Daily Basis for a Martian Year
- Characterize the Small Scale Structure of the Atmosphere and
Ionosphere
Gravity
- Develop a Global, High-Resolution Model for the Gravitational
Field
- Determine Both Local and Broad Scale Density Structure and
Stress State of Martian Crust and Upper Mantle
Instrumentation:
Spacecraft Telecommunications subsystem supplemented with an
Ultrastable Oscillator and elements of the DSN tracking stations
Measurements:
- Signal Strength and Carrier Frequency
- Ultrastable Oscillator Provides Frequency Reference
- Frequency:
- 7164.624 MHz Uplink
- 8417.716 MHz Downlink (Closed Loop)
- 8416.368 MHz Downlink (In-Use Mode)
- Stability (Sq. Root of Allan Variance):
- 5X10-12 for 0.1 s Integration
- 1X10-12 for 1.0 s Integration
- 4X10-13 for 10 S to 1000 s Integration
- Electronics
- No Computer
- High Accuracy Clock Generator
Science Team
G.L. Tyler, Stanford U. - Team Leader
Team Members:
G. Balmino - BGI (France)
D. Hinson - Stanford U.
E. Sjogren - JPL
D. Smith - NASA/GSFC
R. Woo - JPL