ORS Satellite Bus

Data current as of 2026-07-20.

The ORS bus accounts for 13 cataloged objects, of which 8 are in orbit and 0 are active. 5 have reentered. Most are built by TRW. The largest operator on this bus is AFSSD. The first launched in 1966, the most recent in 1971.

8
In orbit
0
Active
13
Total launched
5
Reentered

ORS launched per year

1 2 3 4 1966: 2 launched, 1 since reentered 1967: 4 launched, 1 since reentered 1968: 3 launched, 2 since reentered 1969: 3 objects launched 1970: 0 objects launched 1971: 1 launched, 1 since reentered 1966 1967 1968 1969 1970 1971
Still in orbit Since reentered Click a year to list its satellites.

Typical specifications

Most common values across cataloged ORS satellites.

Manufacturer TRW
Purpose Experimental
Launch mass 9 kg
Dry mass 9 kg
Length 0.3 m
Diameter 0.3 m
Span 0.3 m
Shape Oct Cyl
Power Solar cells
Propulsion None
Equipment various: see above
Typical orbit 2831 min period, 33° inclination

Top operators

AFSSD 5 SAMSO 5 NASA 3

Top countries

US 13

ORS satellites

Track any of them live in KeepTrack.

Name NORAD COSPAR Owner Launched Orbit Status Track
TETR 4 TETR 3 05492 1971-083B GSFC Sep 29, 1971 88 min, 33.1° Reentered
OV5-9 OV5-9 03952 1969-046C SAMSO May 23, 1969 3115 min, 32.9° Inactive
ERS 26 (OV5-6) ERS 26 03951 1969-046B SAMSO May 23, 1969 3115 min, 32.9° Inactive
ERS 29 (OV5-5) ERS 29 03950 1969-046A SAMSO May 23, 1969 3120 min, 34.0° Inactive
TETR 2 TETR 2 03534 1968-100B GSFC Nov 8, 1968 88 min, 32.8° Reentered
ERS 21 (OV5-4) ERS 21 03430 1968-081C SAMSO Sep 26, 1968 1436 min, 13.6° Inactive
ERS 28 (OV5-2) ERS 28 03429 1968-081B SAMSO Sep 26, 1968 346 min, 26.1° Reentered
TATS 1 (TETR-1) TTS 1 03067 1967-123B GSFC Dec 13, 1967 88 min, 32.9° Reentered
ERS 27 (OV5-1) ERS 27 02769 1967-040E AFSSD Apr 28, 1967 2827 min, 37.5° Inactive
ERS 20 (OV5-3) ERS 20 02768 1967-040D AFSSD Apr 28, 1967 2831 min, 35.1° Inactive
ERS 18 ERS 18 02767 1967-040C AFSSD Apr 28, 1967 2831 min, 35.2° Inactive
ERS 15 ORS 1 02412 1966-077C AFSSD Aug 19, 1966 168 min, 90.3° Inactive
ERS 16 ORS 2 02202 1966-051C AFSSD Jun 9, 1966 90 min, 89.9° Reentered

Frequently asked questions

How many ORS satellites are there?

The catalog lists 13 objects built on the ORS bus. 8 are in orbit and 5 have reentered.

How many ORS satellites are in orbit?

8 ORS objects are currently in orbit, of which 0 carry an active status.

Who builds the ORS bus?

The ORS bus is most commonly built by TRW.

When did the first ORS satellite launch?

The first cataloged ORS satellite launched in 1966, and the most recent in 1971.

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