EXPLORER 4
| Launched | 25 July 1958 |
| Flight ended | 22 October 1959 |
| Status | Decayed |
| Launch site | Air Force Eastern Test Range, Florida, USA |
| Owner | United States |
| NORAD ID | 9 |
| COSPAR ID | 1958-005A |
| Observing |
EXPLORER 4
| Launched | 25 July 1958 |
| Flight ended | 22 October 1959 |
| Status | Decayed |
| Launch site | Air Force Eastern Test Range, Florida, USA |
| Owner | United States |
| NORAD ID | 9 |
| COSPAR ID | 1958-005A |
| Observing |