BISONSAT
launched 2015low orbitNORAD 40974 · 2015-058L
- Height
- 571.2 km
- From center
- 6,945.4 km
- Sunlight
- Sunlit
- Speed
- 7.544 km/s
- Ground speed
- 6.736 km/s
- Over
- 25.773° N, 155.411° E
Passes
Known downlinks
- 437.376 MHz, Telemetry, FSK
From SatNOGS DB (CC BY-SA 4.0), contributed by listeners and not checked by SeekSat. Some may be off the air.
Elements are 13 hours old, from CelesTrak GP data (groups: active), fetched 3 h ago.
Technical details
Mean elements
Elements are 13 hours old, from CelesTrak GP data (groups: active), fetched 3 h ago.How accurate is this?
- Perigee
- 442 km
- Apogee
- 570 km
- Period
- 94.74 min
- Inclination
- 64.76°
- Eccentricity
- 0.0093506
- Semi-major axis
- 6,884.1 km
- Epoch
- 2026-11-15T10:33:51Z
Orbit check
The live speed and distance fit this orbit to within 0.062%.
Vis-viva: v²r/GM = 0.9917 and 2 − r/a = 0.9911
Raw elements
2LE
1 40974U 15058L 26319.44017536 .00013293 00000+0 56297-3 0 9993 2 40974 64.7573 43.3327 0093506 348.0450 11.8455 15.19486892138578
3LE
BISONSAT 1 40974U 15058L 26319.44017536 .00013293 00000+0 56297-3 0 9993 2 40974 64.7573 43.3327 0093506 348.0450 11.8455 15.19486892138578
OMM
{
"OBJECT_NAME": "BISONSAT",
"OBJECT_ID": "2015-058L",
"EPOCH": "2026-11-15T10:33:51.151104",
"MEAN_MOTION": 15.19486892,
"ECCENTRICITY": 0.0093506,
"INCLINATION": 64.7573,
"RA_OF_ASC_NODE": 43.3327,
"ARG_OF_PERICENTER": 348.045,
"MEAN_ANOMALY": 11.8455,
"EPHEMERIS_TYPE": 0,
"CLASSIFICATION_TYPE": "U",
"NORAD_CAT_ID": 40974,
"ELEMENT_SET_NO": 999,
"REV_AT_EPOCH": 13857,
"BSTAR": 0.00056297,
"MEAN_MOTION_DOT": 0.00013293,
"MEAN_MOTION_DDOT": 0
}How we compute these
- Altitude
- Height above the WGS84 ellipsoid, the standard model of Earth's shape, straight below the satellite.
- Speed
- The length of SGP4's velocity vector in the TEME frame: the inertial speed. It is not the speed over the ground.
- Ground speed
- How fast the point below the satellite moves across Earth's surface, with Earth's rotation taken out.
- From Earth's center
- Distance from Earth's center, from SGP4's position.
- Latitude and longitude
- The point on the WGS84 ellipsoid straight below the satellite, from SGP4's position turned into Earth-fixed coordinates.
- Sunlight
- How much sunlight reaches the satellite past Earth and its atmosphere. Light grazing Earth is dimmed by air and ozone, bent into the shadow by refraction, and blocked below 10 km (clouds and haze); the Sun's disc is darker at its edge. So the satellite fades over a few seconds in low orbit and a couple of minutes in geostationary orbit, reddening as it goes, rather than switching off. The atmosphere is a clear standard one: haze from a large volcanic eruption can make the real fade come a few seconds early.
- Orbit check (vis-viva)
- v²r/GM uses the live speed and distance above, with GM = 398,600.4418 km³/s². Vis-viva says it equals 2 − r/a, where a is the mean semi-major axis. They agree as closely as SGP4's mean elements allow, usually within 1%.
- Mean elements
- Perigee, apogee, period, eccentricity, inclination and semi-major axis are mean elements from the published set, not instantaneous values. Perigee and apogee heights are above Earth's equatorial radius (6,378 km).
- Epoch
- The epoch is the moment the element set describes. Positions get less accurate the further you are from it.
- How accurate is this?
- Positions are predictions from the published elements, not live tracking. Through SGP4 they are usually within a kilometre or two near the epoch and drift by a few km a day after it, more for low or manoeuvring satellites. The map shows ground positions, the point straight below the satellite, so dots that look close can be thousands of km apart in height. Good for passes and tracks; not for judging close approaches between objects.