TDRS Satellite Bus
Data current as of 2026-07-20.
The TDRS bus accounts for 6 cataloged objects, of which 6 are in orbit and 4 are active. Most are built by TRW. The largest operator on this bus is NASA. The first launched in 1983, the most recent in 1995.
6
In orbit
4
Active
6
Total launched
0
Reentered
TDRS launched per year
Still in orbit Click a year to list its satellites.
Typical specifications
Most common values across cataloged TDRS satellites.
| Manufacturer | TRW |
|---|---|
| Purpose | Communication, data relay |
| Launch mass | 2534 kg |
| Dry mass | 1673 kg |
| Length | 1.3 m |
| Diameter | 2.4 m |
| Span | 17.4 m |
| Shape | Box + Dish + 2 Pan |
| Power | 2 deployable solar arrays, batteries |
| Propulsion | AOCS |
| Design life | 10 years (design) |
| Equipment | 4 (+2) 25W Ku-band TWTAs for LP (linearly polarized) zone coverage 2 (+2) 1.5W Ku-band TWTAs for CP (circularly polarized) spot coverage 2 (+4) 25W Ku-band TWTAs for LP zone coverage 2 (+2) 1.5W Ku-band TWTAs for CP spot coverage 12 5W TWTAs for LP C-Band up/down 2 (+2) 26W S-band SSPAs (used for intersatellite links) 8 (+4) 3.5W S-band SSPAs (used for intersatellite links) |
| Typical orbit | 1436 min period, 13° inclination |
Top operators
Top countries
US 6
TDRS satellites
Track any of them live in KeepTrack.
| Name | NORAD | COSPAR | Owner | Launched | Orbit | Status | Track |
|---|---|---|---|---|---|---|---|
| TDRS 7 TDRS 7 | 23613 | 1995-035B | GSFC | Jul 13, 1995 | 1436 min, 13.4° | Active | ◉ |
| TDRS 6 TDRS-6 | 22314 | 1993-003B | GSFC | Jan 13, 1993 | 1436 min, 14.2° | Active | ◉ |
| TDRS 5 TDRS 5 | 21639 | 1991-054B | GSFC | Aug 2, 1991 | 1436 min, 14.1° | Active | ◉ |
| TDRS 4 TDRS 4 | 19883 | 1989-021B | GSFC | Mar 13, 1989 | 1462 min, 12.8° | Inactive | ◉ |
| TDRS 3 TDRS 3 | 19548 | 1988-091B | GSFC | Sep 29, 1988 | 1436 min, 12.6° | Active | ◉ |
| TDRS 1 TDRS 1 | 13969 | 1983-026B | GSFC | Apr 4, 1983 | 1458 min, 8.6° | Inactive | ◉ |
Frequently asked questions
How many TDRS satellites are there?
The catalog lists 6 objects built on the TDRS bus. 6 are in orbit and 0 have reentered.
How many TDRS satellites are in orbit?
6 TDRS objects are currently in orbit, of which 4 carry an active status.
Who builds the TDRS bus?
The TDRS bus is most commonly built by TRW.
When did the first TDRS satellite launch?
The first cataloged TDRS satellite launched in 1983, and the most recent in 1995.