DMSP Block 4B Satellite Bus
Data current as of 2026-07-20.
The DMSP Block 4B bus accounts for 3 cataloged objects, of which 3 are in orbit and 0 are active. Most are built by RCA. The largest operator on this bus is SAMSO. The first launched in 1968, the most recent in 1969.
3
In orbit
0
Active
3
Total launched
0
Reentered
DMSP Block 4B launched per year
Still in orbit Click a year to list its satellites.
Typical specifications
Most common values across cataloged DMSP Block 4B satellites.
| Manufacturer | RCA |
|---|---|
| Purpose | Meteorology |
| Launch mass | 79 kg |
| Dry mass | 79 kg |
| Length | 0.7 m |
| Diameter | 0.8 m |
| Span | 0.8 m |
| Shape | Oct Cyl |
| Power | Solar cells, batteries |
| Propulsion | ? |
| Equipment | ? |
| Typical orbit | 101 min period, 99° inclination |
Top operators
SAMSO 3
Top countries
US 3
DMSP Block 4B satellites
Track any of them live in KeepTrack.
| Name | NORAD | COSPAR | Owner | Launched | Orbit | Status | Track |
|---|---|---|---|---|---|---|---|
| OPS 1127 (DMSP 4B F3) OPS 1127 | 04047 | 1969-062A | SAMSO | Jul 23, 1969 | 101 min, 98.4° | Inactive | ◉ |
| OPS 4078 (DMSP 4B F2) OPS 4078 | 03510 | 1968-092A | SAMSO | Oct 23, 1968 | 101 min, 98.6° | Inactive | ◉ |
| OPS 7869 (DMSP 4B F1) OPS 7869 | 03266 | 1968-042A | SAMSO | May 23, 1968 | 102 min, 98.6° | Inactive | ◉ |
Frequently asked questions
How many DMSP Block 4B satellites are there?
The catalog lists 3 objects built on the DMSP Block 4B bus. 3 are in orbit and 0 have reentered.
How many DMSP Block 4B satellites are in orbit?
3 DMSP Block 4B objects are currently in orbit, of which 0 carry an active status.
Who builds the DMSP Block 4B bus?
The DMSP Block 4B bus is most commonly built by RCA.
When did the first DMSP Block 4B satellite launch?
The first cataloged DMSP Block 4B satellite launched in 1968, and the most recent in 1969.