12' Sphere Satellite Bus
Data current as of 2026-07-20.
The 12' Sphere bus accounts for 4 cataloged objects, of which 0 are in orbit and 0 are active. 4 have reentered. Most are built by SCHJ. The largest operator on this bus is NASA. The first launched in 1961, the most recent in 1968.
0
In orbit
0
Active
4
Total launched
4
Reentered
12' Sphere launched per year
Still in orbit Since reentered Click a year to list its satellites.
Typical specifications
Most common values across cataloged 12' Sphere satellites.
| Manufacturer | SCHJ |
|---|---|
| Launch mass | 8 kg |
| Dry mass | 8 kg |
| Length | 3.6 m |
| Diameter | 3.6 m |
| Span | 3.6 m |
| Shape | Sphere |
Top operators
Top countries
US 4
12' Sphere satellites
Track any of them live in KeepTrack.
| Name | NORAD | COSPAR | Owner | Launched | Orbit | Status | Track |
|---|---|---|---|---|---|---|---|
| EXPLORER 39 (ADI-3) Explorer 39 | 03337 | 1968-066A | LARCN | Aug 8, 1968 | 89 min, 80.5° | Reentered | ◉ |
| EXPLORER 24 (ADI-2) Explorer 24 | 00931 | 1964-076A | LARCN | Nov 21, 1964 | 92 min, 81.3° | Reentered | ◉ |
| EXPLORER 19 (ADI-1) Explorer 19 | 00714 | 1963-053A | LARCN | Dec 19, 1963 | 90 min, 78.7° | Reentered | ◉ |
| EXPLORER 9 Explorer 9 | 00081 | 1961-004A | LARCN | Feb 16, 1961 | 93 min, 38.8° | Reentered | ◉ |
Frequently asked questions
How many 12' Sphere satellites are there?
The catalog lists 4 objects built on the 12' Sphere bus. 0 are in orbit and 4 have reentered.
How many 12' Sphere satellites are in orbit?
0 12' Sphere objects are currently in orbit, of which 0 carry an active status.
Who builds the 12' Sphere bus?
The 12' Sphere bus is most commonly built by SCHJ.
When did the first 12' Sphere satellite launch?
The first cataloged 12' Sphere satellite launched in 1961, and the most recent in 1968.