33759 · IRIDIUM 33 DEB
debris — Iridium–Cosmos collision, 2009
Orbit
Apogee786km
Perigee604km
Inclination86.4°
RCS0.058m²
Characterization
- Object type
- debris
- Origin
- Iridium–Cosmos collision, 2009
- Radar cross-section
- 0.058 m²
- Active conjunctions
- 1
Derived elements
two-body · vis-viva
Semi-major axis7073.1km
Eccentricity0.01287
Period98.67min
Mean motion14.5943rev/day
Velocity at perigee7.604km/s
Velocity at apogee7.411km/s
LEO · computed from the catalogued apsides with μ = 398600.4418 km³/s² and R⊕ = 6378.137 km (WGS-84).
Secular perturbations
J2 oblateness
Nodal regression-0.4358deg/day
Apsidal rotation-3.4016deg/day
Ω̇ node · ω̇ argument of perigee, secular rates from the J2 term.
J2 is the dominant perturbation at this altitude. The plane precesses relative to the fleet's, so the encounter geometry walks through the catalogue rather than repeating.
Orbit determination
general perturbations
PropagatorSGP4
Epoch age6.2h
Observation arc7.2d
Inferred mass28.37kg
Ballistic coeff.222.3kg/m²
- Covariance delivered
- position only
General-perturbations fit — an SGP4 mean-element set. The analytic theory carries no formal covariance, so screening substitutes a modelled one and the resulting Pc is correspondingly softer.
Conjunctions against the fleet
1 active
| Event | Primary | TCA | Miss km | Rel vel km/s | Pc |
|---|---|---|---|---|---|
| CJ-4459 | OG-1Meridian-1 | T−52:12:00 | 1.710 | 12.07 | 5.0×10−5 |
Spacecraft: OG-1