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View the JPL OSTM/Jason-2 Spacecraft Fact Sheet (PDF 1.4 MB).
View the NASA OSTM/Jason-2 Mission Fact Sheet (PDF 252 Kb).

JPL OSTM/Jason-2 Spacecraft Fact Sheet

Science Objectives

- Extend the time series of ocean surface topography measurements beyond TOPEX/Poseidon (T/P) and Jason to accomplish two decades of observations
- Provide a minimum of 3 years measurement of global ocean surface topography
- Determine the variability of ocean circulation at decadal time scales from combined data record with T/P and Jason
- Improve the measure of the time-averaged ocean circulation
- Improve the measure of global sea-level change
- Improve open ocean tide models

Engineering Objectives

- Launch into the same orbit as Jason
- Maintain the same measurement accuracy of Jason (3.3 cm) with a goal of achieving 2.5 cm
- Maintain the stability of the global mean sea level measurement with a drift less than 1 mm/year over the life of the mission
- Maintain the accuracy of significant waveheight to 50 cm or 10% of the value (whichever is greater)

Mission

- International Collaboration: NASA, NOAA, CNES, EUMETSAT
- Launch Date: June 15, 2008
- Launch Vehicle: United Launch Alliance Delta II 7320
- Launch Site: Vandenberg AFB, California
- Mission Operations: NOAA, EUMETSAT

Orbit

- Altitude: 1336 km
- Circular, non-sun-synchronous, 66° inclination
- Global data coverage between 66°N and 66°S latitude
- 10-day repeat of ground track (±1-km accuracy)
- Coverage of 95% of ice-free oceans every 10-days

Spacecraft

- Based on Alcatel's Proteus bus
- Total mass: 510 kg (1124 lbs)
- Power: 500W
- Communication through the NOAA Tracking Stations at Alaska, and Wallops Island, Virginia along with a EUMETSAT Station at Usingen, Germany
- Reaction wheels and magnetic torque rods maintain 3-axis stabilization and nadir-pointing
- Hydrazine propellant system provides orbital maintenance

Payload/Sensors

- CNES Poseidon-3 Altimeter (C- and Ku-band) measures height above sea surface
- NASA Advanced Microwave Radiometer (AMR) Three-frequency radiometer measures total water vapor along altimeter path to correct for pulse delay
- CNES Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) Doppler tracking antenna receives ground signals for precise orbit determination, satellite tracking, and ionospheric correction data for CNES altimeter
- NASA Global Positioning System Payload (GPSP) receiver provides precise orbit ephemeris data
- NASA Laser Retroreflector Array (LRA) works with ground stations to track satellite and calibrate the other satellite location systems, and verify altimeter measurements

Data Processing

- Data Processing, archive and distribution by CNES, EUMETSAT and NOAA depending on type of product