Conjunction Event Detail

    Medium Risk
    Monitor closely. Maneuver recommended for primary asset.
    1.221019E-5
    Collision Probability (Pc)
    Last Conjunction Event Update Time 2026-09-04T11:55:44+0800
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    1 Object 1

    Name USA 55
    AOE ID 20547
    NORAD ID 20547
    Object Type PAYLOAD
    Country
    US US
    VS

    2 Object 2

    AOE ID 52630
    NORAD ID 52630
    Object Type PAYLOAD
    Country
    US US

    Conjunction Constraints

    Parameter USA 55 STARLINK-3989
    Time of Closest Approach 2026-09-04T11:23:49+0000
    Collision Probability (Pc) 1.221019E-5
    Conjunction Distance (km) 1.033 km
    Relative Speed (km/s) 5.574 km/s
    Conjunction Risk Parameters R (Radial): 0.481 | I (In-track): 0.853 | C (Cross-track): -0.33
    Collision Risk Index (CRI) 0.57
    X Position (km) -6525.467 -6525.65
    Position Y (km) -799.432 -799.722
    Position Z (km) 1912.118 1913.092
    Velocity X (km/s) 2.052 2.242
    Velocity Y (km/s) 0.821 -4.526
    Velocity Z (km/s) 7.284 5.724

    Orbital Parameters 国际轨道数据源

    Parameter USA 55 STARLINK-3989
    Semimajor Axis (a) 6809.881 km 6848.869 km
    Eccentricity (e) 0.005379 0.000122
    Inclination (i) 94.0952° 53.1594°
    RAAN 187.8110° 180.7842°
    Perigee Argument 187.8301° 88.0144°
    Mean Anomaly (M) 172.2121° 272.0997°
    Apogee 468.378 km 471.571 km
    Perigee 395.110 km 469.893 km
    Orbit Epoch 2026-09-03T19:46:48+0000 2026-09-03T02:25:19+0000

    USA 55 & STARLINK-3989 Collision Probability (Pc) Trend

    USA 55 & STARLINK-3989 Collision Probability (Pc) TrendNot Available

    USA 55 & STARLINK-3989 Miss Distance (Miss Distance) Trend

    USA 55 & STARLINK-3989 Miss Distance (Miss Distance) TrendNot Available

    USA 55Miss Distance Trend with All Objects

    Object 1 Miss Distance TrendNot Available

    STARLINK-3989Miss Distance Trend with All Objects

    Object 2 Miss Distance TrendNot Available

    USA 55Collision Probability Trend

    Object 1 Probability TrendNot Available

    STARLINK-3989Collision Probability Trend

    Object 2 Probability TrendNot Available

    Nearby Objects with USA 55

    No nearby objects data