EXPLORER 18
| Launched | 26 November 1963 |
| Flight ended | 29 December 1965 |
| Status | Decayed |
| Launch site | Air Force Eastern Test Range, Florida, USA |
| Owner | United States |
| NORAD ID | 693 |
| COSPAR ID | 1963-046A |
| Alternative names |
IMP-1 |
| Observing |
Launched alongside
ATLAS CENTAUR 2 ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB ATLAS CENTAUR 2 DEB