Tansei 4

 1980-015A

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Tansei-4 (MS-T4) flew on the first Mu-3S launch. It tested the spin-stabilized attitude control mode for ASTRO-A and the momentum wheel stabilization needed for ASTRO-B and EXOS-C. It also carried an X-ray astronomy experiment.

Tansei-4 is 1.00 dia 0.81 high with a mass of 185 kg, octagonal cylinder plus 4 panels.

The M-3A₂ motor is 1.14m dia 2.50m long, with mass 1240 kg full 157 empty. Burn time was 45s, thrust 66.9 kN.

Tansei-4
Date	Time	Event	Orbit
1980 Feb 17	0040	Launch by Mu-3S-1	KASC
		T+0:08 SB burnout
		T+0:09 SB sep
		T+1:10 B1 burnout
		T+1:20 B1 sep
		T+1:26 B2 start
		T+2:38 B2 burnout
		T+2:42 Fairing sep (2 parts)
		T+3:11 B2 orbit epoch
		T+4:00 Spinup
	0047	T+7:37 B2 sep
	0047	T+7:42 B3 start	-5468 x 523 x 38.73
		T+8:09 B2 apogee
	0048	T+8:35 B3 burnout
	0049	T+9:32 B3 sep	95.7 517 x 602 x 38.7
	0049	T+9:34 B3 yo release
	0230?	Yo-yo despin, 2 masses released
1983 May 12		Reentered