The test satellite “TANSEI” verified performance of M-4S rocket and, after insert into orbit, research on space environment and satellite performance test.

Name (pre-launch in parentheses) TANSEI (MS-T1)
International Designation code 1971-11A
Objectives Performance verification of M-4S rocket and, after insertion into orbit, research on space environment and satellite performance test.
Launch Date 13:00, February 16, 1971 (JST)
Launch Location Kagoshima Space Center (Uchinoura)
Launch Vehicle M-4S-2
Weight 63kg
Shape 26-hedron in a sphere with a 75cm diameter
Orbital Altitude Perigee 990 km, Apogee 1,100 km
Orbital Inclination 30°
Type of orbit Near-circular
Orbital Period 106 min
Scientific Instruments ・Telemetry transmitter
・Command receiver and decoder
・Magnetic tape-type data recorder, etc.
・Installed 6-reflection mirror on the satellite surface
・Carrying silver oxide–zinc battery as power supply
End of Operation February 23, 1971
Operation The signal of the first rotation after launch was received from 14:50:40 to 15:09:12, confirming that the satellite had entered into orbit. Thereafter, observation at Uchinoura continued until 15:00 on February 23 (96 rotations). During the period, all the onboard instruments, except for an instrument to check solar-battery performance, functioned normally. By replaying the data recorder 37 times, abundant data were retrieved including temperature of various parts of the satellite, power-supply voltage and current, satellite altitude and spin status, etc. Tests for telemetry and command systems were performed without problems. After analysis, it was confirmed that temperature and environment inside the satellite were properly maintained as expected and the attitude of the satellite was stable.