| Name of Satellite, Alternate Names | Keyhole 4 (Advanced KH-11, Advanced Keyhole, Improved Crystal, EIS-2, 8X Enhanced Imaging System, NROL 14, USA 161) |
| Country of Operator/Owner | USA |
| Operator/Owner | National Reconnaissance Office (NRO) |
| Users | Military |
| Purpose | Reconnaissance |
| Class of Orbit | LEO |
| Type of Orbit | Sun-Synchronous |
| Longitude of GEO (degrees) | 0 |
| Perigee (km) | 202 |
| Apogee (km) | 1041 |
| Eccentricity | 0.0600014303082314 |
| Inclination (degrees) | 97.8 |
| Period (minutes) | 97.13 |
| Launch Mass (kg.) | 18000 |
| Dry Mass (kg.) | 10000 |
| Power (watts) | |
| Date of Launch | 05-10-2001 |
| Expected Lifetime | 5+ yrs. |
| Contractor | Lockheed Martin |
| Country of Contractor | USA |
| Launch Site | Vandenberg AFB |
| Launch Vehicle | Titan IV |
| COSPAR Number | 2001-044A |
| NORAD Number | 26934 |
| Comments | $1 billion satellite; high resolution surveillance; can resolve square or circular objects as small as 10 cm but linear structures of 5-8 cm can also be detected. Reported to have reduced capacity due to electrical problems. |