| Name of Satellite, Alternate Names | TacSat 4 |
| Country of Operator/Owner | USA |
| Operator/Owner | Naval Research Laboratory |
| Users | Military |
| Purpose | Technology Development |
| Class of Orbit | Elliptical |
| Type of Orbit | |
| Longitude of GEO (degrees) | 0 |
| Perigee (km) | 658 |
| Apogee (km) | 11836 |
| Eccentricity | 0.442973765554411 |
| Inclination (degrees) | 63.64 |
| Period (minutes) | 235.16 |
| Launch Mass (kg.) | 450 |
| Dry Mass (kg.) | |
| Power (watts) | 1000 |
| Date of Launch | 27-09-2011 |
| Expected Lifetime | |
| Contractor | Naval Research Laboratory/Johns Hopkins University Applied Physics Laboratory |
| Country of Contractor | USA |
| Launch Site | Kodiak Launch Complex |
| Launch Vehicle | Minotaur 4 |
| COSPAR Number | 2011-052A |
| NORAD Number | 37818 |
| Comments | 10 Ultra High Frequency (UHF) channels; allows forward deployed troops to communicate using existing hand-held radios without the need to stop and point an antenna towards the satellite |