Subscribe with SteadyUSA 521, 522 (NROL 174 PL1, 2)
The NROL 174 launch carried two not yet identified payloads for the NRO to be launched on a Minotaur-4 rocket from Wallops Island. The target orbit is not known.
Amateur observers have found the satellites in 1100 km orbits with an iclination of 63.4. This is the same orbit as previous NOSS/Intruder duplets launches, as well as the Intruder Follow-On (NROL-85, 69 and 77) missions. This might hint to a SIGINT mission related to these programs.
Note: The NROL designations refer to the launch, not to the payload.
| Nation: | USA |
|---|---|
| Type / Application: | SIGINT ? |
| Operator: | NRO |
| Contractors: | ? |
| Equipment: | ? |
| Configuration: | ? |
| Propulsion: | ? |
| Power: | |
| Lifetime: | |
| Mass: | |
| Orbit: | 1100 km × 1100 km, 63.4 |
| Satellite | COSPAR | Date | LS | Launch Vehicle | Remarks | |
|---|---|---|---|---|---|---|
| USA 521 (NROL 174 PL1) | 2025-077A | 16.04.2025 | Va SLC-8 | Minotaur-4 | with USA 521 | |
| USA 522 (NROL 174 PL2) | 2025-077B | 16.04.2025 | Va SLC-8 | Minotaur-4 | with USA 521 |
Launch Sites:
- Va = Vandenberg Space Force Base, California, USA
