Japan Aerospace Exploration Agency ISAS SitemapJAXA Sitemap

TOP > Our Enterprises > Rockets > Satellite Launch Vehicles > M-3SII

M-3SII Satellite Launch Vehicles

M-3SII Satellite Launch Vehicles

Targeting Halley's comet which had been predicted to reappear in 1985 after 76 years, ISAS started to develop the fourth generation Mu launch system, M-3SII, in 1981. It used the first stage of M-3S, and the rest of the stages were replaced by new ones to enhance its payload capability. The M-3SII-1 and -2, with an optional fourth kick stage, sent the first and second Japanese interplanetary probes, SAKIGAKE and SUISEI, into orbit in 1985 to encounter Halley's comet. Seven M-3SII launches out of eight were successful. It could send a 770 kg satellite into low earth orbit.

Mission by M-3SII Launch Vehicle

The vehicle M-3SII-1 is described as follows

    1st st. SOB 2nd st. 3rd st. 4th st.
Total length m 27.785 9.140 13.1235 4.6661 2.0084
Maximum diameter m 1.650 0.735 1.650 1.495 1.400
Weight (ig.) kg 51952.6*1 10248.1 17267.2*3 4208.8 605.65
Weight (b.o.) kg 24718.9*2 2225.1 6950.2*3 910.9 185.05
Propellant weight kg 27098.0 8023.0 10317.0 3297.9 420.60
Freon kg     271.46 87.6  
Hydrazine kg       40.0  
Specific Impulse sec 266*4 266*4 282.0*4 293.1*4 284.6*4
Center of gravity (ig.) % 63.3 61.7 55.1 49.5
Center of gravity (b.o.) % 44.5 47.0 36.2 29.4
Ix (ig.) kg.m.sec2 3537.7 472.5 93.98 6.286
Ix (b.o.) kg.m.sec2 919.2 206.0 13.04 3.536
Iy (ig.) kg.m.sec2 295110.0 11754.0 304.4 14.27
Iy (b.o.) kg.m.sec2 130310.0 5019.0 124.4 6.22
Net payload kg     247.4   SA 138.1
Nozzle expansion ratio   7.80 9.13 23.24 51.84 49.00
Nozzle exit diameter mm 1270.4 725.0 1349.8 1094.4 504.0

*1:including Freon(271.46kg)
*2:including Freon(135.73kg)
*3:including Freon(87.6kg) & Hydrazine(40.0kg)
*4:in vacuum