SB-Wass 3-8 (Intruder 12A & 12B)

USA

Int. spacecraft nº:

US spacecraft nº:

SB-WASS 3-8: Space Based Wide Area Surveillance System. - Also called: NOSS-3 8A & 8B, USA 274 & 274-P/L2, NROL 79)

Launch data:

Type	Intruder 12A	Intruder 12B
NORAD ID	42058	42065
Designation	17011A	17011B
Launch date	01 Mar 2017 - 17:49 UT
Launch site	Va, SLC-3E
Launch vehicle	Atlas V-401 (AV-068)
Mission	Mil: Earth observation
Non-Polaire inclined LEO orbit:
Perigee / Apogee	1009 x 1204 km	1009 x 1204 km
Eccentricity	1,30E-02
Inclination	63.4°	63.5°
Period	107.4 min	107.4 min
Decay

Spacecraft data:

Prime manufacturer	National Reconnaissance Laboratory (NRL)
Platform
Operator	National Reconnaissance Laboratory (NRL)
Mass at launch	kg
Dry Mass	6500 kg
Basic shape
Dimension (m)
Equipment
Solar array
Stabilization
Propulsion
DC power
Design lifetime

Description:

USA 274 is a military satellite that carries equipment to track ships and aircraft via their radio transmissions. Positions of the origin of the transmissions are determined by triangulation. Each launch consists of two satellites of similar size in the same orbit. Both satellites maneuver to stationkeep relative to one another.

Mission details:

ULA launched Atlas V serial AV-068 on Mar 1, 2017 from Vandenberg, carrying a National Reconnaissance Office payload to orbit on NRO launch NROL-79.
The payload is thought to be an NRO/Navy signals intelligence system code-named INTRUDER consisting of a pair of satellites in 1010 x 1200 km x 63 deg orbit. The Centaur second stage was deorbited south of Australia on the first orbit with impact around 1956 UTC.

External links:

Satellite tracking: Real time satellite tracking Intruder 12A
Satellite tracking: Real time satellite tracking Intruder 12B

Ref.: #7(JR736,737), #226, #228 - update: 12.12.17