SJ 4 [CAST]
Official name SJ-4
Alternative name Shi Jian 4
Cospar ID 1994-010A
Norad ID 22996
Launch date 1994-02-08
Launch site XSC
Launch vehicle CZ-3A
Country/Organization China
Type application Technology
RCS size LARGE
Decay date ON ORBIT
Period (min) 310.89
Inclination (deg) 28.96
Perigee (km) 344
Apogee (km) 17304
Eccentricity 0.961015412511333
Mean motion (revs. per day) 4.63186336003088
Semi-Major axis (km) 15202.135
Raan (deg) 199.3394
Arg of perigee (deg) 283.9664
Shape Cyl
Mass (kg) 392.47
Diameter (m) 1.6
Height (m) 2.2
Span (m^2) 2.2
Lifetime 6 months
Contractors CAST
Power Solar cells, batteries

SJ 4 (Shi Jian 4) was a satellite to monitor the space radiation environment and its effects in an elliptical orbit.

SJ-4 was built by CAST. The spin stabilized spacecraft had a mass of 397 kg with a diameter of 1.6 m and a height of 2.1 m.

The satellite was equipped with six instruments:

  • EED (High Energy Electron Detector)
  • EPS (High Energetic Proton and Heavy Ion Detector)
  • ESA (Electrostatic Analyzer)
  • SEEM (Dynamic Single Event Effect Monitor)
  • SEUM (SRAM Single Event Upset Monitor)
  • SPM (Surface Potential Monitor)

The satellite was launched from Xichang on the maiden flight of the CZ-3A rocket and was put into a geosynchronous transfer orbit of 210 km × 36125 km with an inclination of 28.6º. It operated for about six months.

Satellite COSPAR Date LS Launch Vehicle Remarks
SJ-4 1994-010A 1994-02-08 XSC CZ-3A with KF 1