Object 100689 beside Sentinel-3A
An object Space-Track has not named yet moved up beside a satellite of European Commission DG-GROW Directorate I/2, Copernicus Unit, 59 km away at the nearest, and has stayed there for 5 days 18 h.
Beside right now · confirmed on October 28, 2026
- Nearest
- 58.8 km
- Oct 29 · 3:43 PM UTC
- Beside for
- 5 days 18 h
- since Oct 28, 6:04 AM UTC
- Took to come beside
- 21 days
- same plane Oct 7, same height Oct 7
- Orbit
- LEO
- low Earth orbit
The one it came up to
Sentinel-3A
European Commission DG-GROW Directorate I/2, Copernicus Unit, I-EU
41335 · 2016-011A · launched Feb 16, 2016
Whether either operator has said what this rendezvous was is not recorded yet. What others said is below; this page draws no conclusion.
The stages
Each step is one of Space-Track’s element sets, run through SGP4 and set against the other’s. A stage is raised by one set and confirmed when a later one agrees.
published 5:41 PM UTC
Same plane seen
Object 100689’s orbit was found in Sentinel-3A’s plane, 0.031° off, and 4.76 km higher.
Δa +4.76 km · θ 0.031°
published 5:41 PM UTC
Same height seen
Object 100689’s orbit had come to within 4.76 km of Sentinel-3A’s height.
1,282.14 km · Δa +4.76 km · θ 0.031°
published 7:01 PM UTC
Beside raised
A set placed Object 100689 beside Sentinel-3A. One set raises it; a later one must agree.
59.97 km · 59.5 km a day later · Δa +0.00 km · θ 0.029°
published 7:01 PM UTC
Beside confirmed
A later set agreed: Object 100689 stayed beside Sentinel-3A.
59.84 km · 59.4 km a day later · Δa +0.00 km · θ 0.028°
Reported elsewhere
No report elsewhere names this rendezvous yet.
Our Article about it: Sentinel-3C sends its first images of Earth two weeks after launch
Every verdict as numbers
| Stage | State | Set epoch (UTC) | Published (UTC) | Distance | A day later | Δa | θ | Exclusion |
|---|---|---|---|---|---|---|---|---|
| Same plane | seen | 2026-10-07 15:11:08 | 2026-10-07 17:41:50 | +4.76 km | 0.0308° | |||
| Same height | seen | 2026-10-07 15:11:08 | 2026-10-07 17:41:50 | 1,282.14 km | +4.76 km | 0.0308° | ||
| Beside | raised | 2026-10-28 06:04:00 | 2026-10-28 19:01:28 | 59.97 km | 59.49 km | +0.00 km | 0.0287° | |
| Beside | confirmed | 2026-10-28 14:29:04 | 2026-10-28 19:01:28 | 59.84 km | 59.42 km | +0.00 km | 0.0277° |
Δa is the semi-major axis of the one that moved less the other’s; θ is the angle between the two orbits’ planes. A day later is where the set puts the two 24 hours on, with no further manoeuvre. An exclusion tag on any of this rendezvous’s verdicts would keep it off the list; the pair’s other rendezvous are judged on their own.