| Name of the satellite | IMP-B |
|---|---|
| Other name(s) | Explorer 21 IMP 2 00889 |
| COSPAR designation | 64-060A |
| Project(s) Manager(s) of the satellite | Paul Butler (retired) |
| Institute of the project(s) manager(s) | NASA-GSFC |
| Country or Space Agency | USA |
| Link(s) to Web site(s) | http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1964-060A |
| Launch date (dd-mm-yyyy) | 04-10-1964 |
| Termination date (dd-mm-yyyy) | 30-01-1966 |
| Lifetime of the satellite (month) | 15 |
| Type of the orbits | HEO |
| (Initial) Perigee (km) | 197 |
| (Initial) Apogee (km / Re) | 101940 / 16 |
| Orbital period (min / hour) | 2097 / 34.95 |
| Spin rate (rpm) | 14.6 |
| Eccentricity | 0.86478 |
| Inclination (°) | 33.5 |
| Observed regions | Magnetosphere, magnetosheath, magnetopause |
| Observed waves | ***** |
| Name of the experiment | Fluxgate Magnetometer |