OTS Satellite Bus

Data current as of 2026-07-20.

The OTS bus accounts for 3 cataloged objects, of which 3 are in orbit and 0 are active. Most are built by BAES. The largest operator on this bus is European Space Agency. The first launched in 1978, the most recent in 1984.

3
In orbit
0
Active
3
Total launched
0
Reentered

OTS launched per year

1 1978: 1 object launched 1979: 0 objects launched 1980: 0 objects launched 1981: 1 object launched 1982: 0 objects launched 1983: 0 objects launched 1984: 1 object launched 1978 1979 1980 1981 1982 1983 1984
Still in orbit Click a year to list its satellites.

Typical specifications

Most common values across cataloged OTS satellites.

Manufacturer BAES
Purpose Communication
Launch mass 431 kg
Dry mass 365 kg
Length 2.5 m
Diameter 2 m
Span 13.8 m
Shape Box + 2 Pan
Power 2 deployable solar arrays, batteries
Propulsion Mage 2
Design life 7 years
Equipment 1 (+1) L-band, 1 (+1) C-band
Typical orbit 1452 min period, 8° inclination

Top operators

Top countries

I-ESA 3

OTS satellites

Track any of them live in KeepTrack.

Name NORAD COSPAR Owner Launched Orbit Status Track
MARECS-B2 Marecs 2 15386 1984-114B ESA Nov 10, 1984 1501 min, 13.5° Inactive
MARECS-A Marecs 1 13010 1981-122A ESA Dec 20, 1981 1515 min, 11.6° Inactive
OTS-2 OTS 2 10855 1978-044A ESA May 11, 1978 1452 min, 7.9° Inactive

Frequently asked questions

How many OTS satellites are there?

The catalog lists 3 objects built on the OTS bus. 3 are in orbit and 0 have reentered.

How many OTS satellites are in orbit?

3 OTS objects are currently in orbit, of which 0 carry an active status.

Who builds the OTS bus?

The OTS bus is most commonly built by BAES.

When did the first OTS satellite launch?

The first cataloged OTS satellite launched in 1978, and the most recent in 1984.

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