| Name of Satellite, Alternate Names | Advanced Orion 2 (NROL 6, USA 139) |
| Country of Operator/Owner | USA |
| Operator/Owner | National Reconnaissance Office (NRO) |
| Users | Military |
| Purpose | Electronic Surveillance |
| Class of Orbit | GEO |
| Type of Orbit | |
| Longitude of GEO (degrees) | -14.5 |
| Perigee (km) | 35560 |
| Apogee (km) | 36013 |
| Eccentricity | 0.00537283692906195 |
| Inclination (degrees) | 7.72 |
| Period (minutes) | 1436.14 |
| Launch Mass (kg.) | 4500 |
| Dry Mass (kg.) | |
| Power (watts) | |
| Date of Launch | 09-05-1998 |
| Expected Lifetime | |
| Contractor | TRW Space and Electronics |
| Country of Contractor | USA |
| Launch Site | Cape Canaveral |
| Launch Vehicle | Titan IVA |
| COSPAR Number | 1998-029A |
| NORAD Number | 25336 |
| Comments | ELINT. |