To carry out its mission ERS-2’s orbit must enable its instruments to scan along predetermined paths designed to give optimum coverage for a set number of orbits. To achieve this, ERS-2 is a three-axis-stabilised, Earth-pointing satellite in yaw steering mode (YSM). The elliptical orbit is sun-synchronous, near-polar, with a mean altitude of 785 km, an inclination of 98.5° and a local solar time at the descending node of 10:30 a.m.

orbit_ers2_1 orbit_ers2_2
orbit_ers2_3
ERS-2 orbit Heavens Above

 

Orbit parameters

35-day orbit

Orbital velocity7.45 km/s

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Main characteristics
Semi-major axis 7159.5 km
Eccentricity 0.0001042
Argument of perigee 92.4836°
Inclination (sun-synchronous) 98.55°
Auxiliary data
Reference altitude (equatorial) 799.8 km
Nodal period 50 min 25.5 s
Repeat cycle 35 days
Number of passes per cycle 1002
Ground track separation at Equator 80 km
Orbital velocity 7.45 km/s

 

Further information on ERS (ESA website)