MS-T Satellite Bus

Data current as of 2026-07-20.

The MS-T bus accounts for 3 cataloged objects, of which 1 are in orbit and 0 are active. 2 have reentered. Most are built by ISAS. The largest operator on this bus is JAXA. The first launched in 1974, the most recent in 1980.

1
In orbit
0
Active
3
Total launched
2
Reentered

MS-T launched per year

1 1974: 1 launched, 1 since reentered 1975: 0 objects launched 1976: 0 objects launched 1977: 1 object launched 1978: 0 objects launched 1979: 0 objects launched 1980: 1 launched, 1 since reentered 1974 1975 1976 1977 1978 1979 1980
Still in orbit Since reentered Click a year to list its satellites.

Typical specifications

Most common values across cataloged MS-T satellites.

Manufacturer ISAS
Purpose Technology
Launch mass 128 kg
Dry mass 128 kg
Length 0.5 m
Diameter 0.8 m
Span 0.9 m
Shape Cyl
Power Batteries
Typical orbit 134 min period, 66° inclination

Top operators

Top countries

J 3

MS-T satellites

Track any of them live in KeepTrack.

Name NORAD COSPAR Owner Launched Orbit Status Track
TANSEI-4 (MS-T4) Tansei-4 11706 1980-015A ISAS Feb 17, 1980 88 min, 38.7° Reentered
TANSEI-3 (MS-T3) Tansei-3 09841 1977-012A ISAS Feb 19, 1977 134 min, 65.8° Inactive
TANSEI-2 (MS-T2) Tansei-2 07122 1974-008A ISAS Feb 16, 1974 88 min, 31.2° Reentered

Frequently asked questions

How many MS-T satellites are there?

The catalog lists 3 objects built on the MS-T bus. 1 are in orbit and 2 have reentered.

How many MS-T satellites are in orbit?

1 MS-T objects are currently in orbit, of which 0 carry an active status.

Who builds the MS-T bus?

The MS-T bus is most commonly built by ISAS.

When did the first MS-T satellite launch?

The first cataloged MS-T satellite launched in 1974, and the most recent in 1980.

Satellite data compiled by KeepTrack from CelesTrak, Space-Track, and GCAT, provided under CC BY-NC 4.0.