Home › Other Active Satellites › SITRO-AIS 21
SITRO-AIS 21 — Live Satellite Tracking (NORAD 61739)
Track SITRO-AIS 21 (NORAD catalog number 61739) live on the WatchSat interactive 3D globe above. Its position is propagated in real time from the latest CelesTrak two-line element set using the SGP4/SDP4 orbital model — the same math professional trackers run. It is object E of 2024's 199th orbital launch (COSPAR designation 2024-199E). It went up together with 46 other satellites from that launch still in the active catalog. As of this element set it had completed roughly 14,400 revolutions of Earth.
Moving at about 7.58 km/s, SITRO-AIS 21 flies in low Earth orbit at an altitude of roughly 579 × 597 km, completing one revolution every 96.3 minutes — about 15.0 trips around Earth per day. The orbit is essentially circular (eccentricity 0.0013). Its 97.3° retrograde, near-polar inclination is characteristic of a Sun-synchronous orbit — the type Earth-imaging and weather satellites use to revisit each spot at the same local solar time. Its orbital plane crosses the equator northbound at right ascension 82.6°. Earth's equatorial bulge drifts that plane eastward about 0.94° per day.
Orbital elements
| Orbit regime | low Earth orbit (LEO) |
|---|---|
| Perigee × apogee altitude | ~579 km × 597 km |
| Inclination | 97.32° |
| Orbital period | 96.3 min (14.95 rev/day) |
| Eccentricity | 0.00133 |
| Element set epoch | 2026-09-07 |
| COSPAR designation | 2024-199E |
| NORAD catalog number | 61739 |
This page's orbital elements come from the CelesTrak catalog of 2026-09-08. The live 3D view above fetches its own current CelesTrak data when the page opens, through an edge cache that refreshes roughly every 30 minutes.
About the Other Active Satellites group
SITRO-AIS 21 is one of 4,471 active satellites in WatchSat's general catalog — the broad population of Earth-observation, communications, science, amateur-radio and technology spacecraft outside the giant broadband constellations. Browse all other active satellites live in 3D.
Can you see SITRO-AIS 21 from the ground?
Sometimes. Like most low-Earth-orbit spacecraft, SITRO-AIS 21 is visible only around dawn and dusk, when your sky is dark but the satellite is still sunlit — and whether you can spot it depends on its size and reflectivity. See pass predictions for your location for when it is above your horizon and sunlit.
Related satellites
Nearest catalog neighbors of SITRO-AIS 21 in the Other Active Satellites group — usually craft from the same or adjacent launches:
- SITRO-AIS 15 (NORAD 61738)
- SITRO-AIS 22 (NORAD 61740)
- SITRO-AIS 16 (NORAD 61737)
- SITRO-AIS 24 (NORAD 61741)
- IONOSFERA-M 2 (NORAD 61736)
- SITRO-AIS 23 (NORAD 61742)
Browse the Other Active Satellites directory or the full satellite directory · What is a TLE? · WatchSat live globe