MMS Satellite Bus

Data current as of 2026-07-20.

The MMS bus accounts for 6 cataloged objects, of which 2 are in orbit and 0 are active. 4 have reentered. Most are built by FAIR. The largest operator on this bus is NASA. The first launched in 1980, the most recent in 1992.

2
In orbit
0
Active
6
Total launched
4
Reentered

MMS launched per year

1 2 1980: 1 launched, 1 since reentered 1981: 0 objects launched 1982: 1 launched, 1 since reentered 1983: 0 objects launched 1984: 1 object launched 1985: 0 objects launched 1986: 0 objects launched 1987: 0 objects launched 1988: 0 objects launched 1989: 0 objects launched 1990: 0 objects launched 1991: 1 launched, 1 since reentered 1992: 2 launched, 1 since reentered 1980 1982 1984 1986 1988 1990 1992
Still in orbit Since reentered Click a year to list its satellites.

Typical specifications

Most common values across cataloged MMS satellites.

Manufacturer FAIR
Purpose Earth observation
Launch mass 1938 kg
Dry mass 1863 kg
Length 4 m
Diameter 2.1 m
Span 10 m
Shape Box + 2 Pan
Power Deployable solar array, batteries
Propulsion ?
Design life 3 years design; 28.8 years reached (#5)
Equipment TM, MSS
Typical orbit 96 min period, 66° inclination

Top operators

Top countries

US 6

MMS satellites

Track any of them live in KeepTrack.

Name NORAD COSPAR Owner Launched Orbit Status Track
TOPEX/POSEIDON Topex-Poseidon 22076 1992-052A JPL/CNES Aug 10, 1992 112 min, 66.0° Inactive
EUVE EUVE 21987 1992-031A GSFC Jun 7, 1992 87 min, 28.4° Reentered
UARS UARS 21701 1991-063B GSFC Sep 12, 1991 87 min, 56.9° Reentered
LANDSAT 5 Landsat 5 14780 1984-021A NOAA Mar 1, 1984 96 min, 98.1° Inactive
LANDSAT 4 Landsat 4 13367 1982-072A GSFC Jul 16, 1982 88 min, 98.2° Reentered
SMM Solar Maximum Mission 11703 1980-014A GSFC Feb 14, 1980 87 min, 28.5° Reentered

Frequently asked questions

How many MMS satellites are there?

The catalog lists 6 objects built on the MMS bus. 2 are in orbit and 4 have reentered.

How many MMS satellites are in orbit?

2 MMS objects are currently in orbit, of which 0 carry an active status.

Who builds the MMS bus?

The MMS bus is most commonly built by FAIR.

When did the first MMS satellite launch?

The first cataloged MMS satellite launched in 1980, and the most recent in 1992.

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