- Earth-watching satellite
- Military
- TOPO 1
- NORAD 4363
- 1970-025B
- Low Earth orbit
Current orbit
View on live mapOrbit began over the Gulf of Mexico
Orbit ends over the Pacific Ocean
In the Earth’s shadow since
Back in sunlight
In view from you
Nobody watches TOPO I go over, but a receiver still asks whether it is above the horizon. Say where you are and this card answers.
Your position is rounded to about a kilometre and sent only to the Orbinauts API, to find the pass.
No brightness has been published for TOPO I, so it is not a naked-eye satellite and no city page carries pass times for it. Nothing here estimates one.
Seeing it
There is nothing to go outside for: it is too faint for the naked eye. What it is up there for reaches the ground as pictures and measurements, not as a light in the sky.
Timeline
- Launch
Launched, on the day GCAT records. Source
Summary
Over Russia LIVE
Where is TOPO I?
At 6:21:30 PM UTC TOPO I was over Russia (52.8° N, 94.5° E), 1,093 km up, moving at 7.31 km/s and in the Earth’s shadow.
What is TOPO I?
A satellite that watches the Earth in low Earth orbit, in space since Apr 8, 1970.
Can I see TOPO I?
No, not with the naked eye: no brightness has been published for TOPO I, and nothing here estimates one; what people use is its pictures and measurements of the Earth.
General
- Operator
- US Army Engineer Topographic Laboratories (TOPOCOM, later ACE)
- State
- United States of America
- Built by
- ITT Federal Laboratories
- What it is
- Earth-watching satellite
- Military
- Yes: a defence organisation flies it
- Launched
- Mass
- 18 kg
- Operating
- No: its regular operations have ended
- Orbit class
- Low Earth orbit
From GCAT, Jonathan McDowell’s general catalogue, licensed CC BY 4.0: the operator, the state, the manufacturer, what it is for, that a defence organisation flies it, the launch day, the mass, and whether it is operating. The orbit class is read from its current elements.
Latest orbital data
- Position received
- 6:21 PM UTC
- Station time (UTC)
- 6:21 PM UTC
- Latitude / longitude
- 52.8° N, 94.5° E
- Altitude
- 1,093 km
- Speed
- 7.31 km/s (26,316 km/h)
- Course
- south
- Light
- In the Earth’s shadow until 6:50 PM UTC
- Inclination
- 99.9°
- Orbital period
- 106.9 minutes
- Orbits per day
- 13.47
- This orbit
- 1,080 to 1,083 km
- In shadow
- 35 minutes of each orbit
- In view from
- Within 2,540 km of the point below it
- Elements epoch
- Nov 8, 2026, 6:00 AM, 12 hours old
- Source
- Position from Space-Track orbital elements of Nov 8, 2026, 6:00 AM, 12 hours old.
No operator publishes an ephemeris for TOPO I, so every position here comes from its orbital elements.
In orbit
- Close approaches
- No close approach to TOPO I has been reported publicly in the past thirty days.
From Space-Track’s public conjunction messages; the latest report was issued Nov 8, 2026, 1:11 PM, 3 hours old. Only approaches serious enough to be reported publicly are listed: within three days and, for two bodies near the Earth, closer than a kilometre with a chance of a collision above 1 in 10,000, the level at which NASA moves the ISS.
Launched with
TOPO I shares its launch, 1970-025, with 255 other bodies the catalogue lists in orbit.
Read from the international designators of the US catalogue: the year and the launch number every piece of one launch shares. A body that has come down is no longer listed.
Beside the others
| Satellite | Typical altitude | Orbital period | Mass | In space since |
|---|---|---|---|---|
| TOPO I | 1,080 to 1,083 km | 107 minutes | 18 kg | 1970 |
| Sentinel-5P | 826 to 828 km | 101 minutes | 820 kg | 2017 |
| Suomi NPP | 825 to 829 km | 101 minutes | about 2.1 t | 2011 |
| Sentinel-6MF | 1,332 to 1,344 km | 112 minutes | about 1.2 t | 2020 |
| Sentinel-6B | 1,332 to 1,344 km | 112 minutes | about 1.2 t | 2025 |
| MetOp-SG A1 | 820 to 821 km | 101 minutes | about 4 t | 2025 |
Data and API
The current elements from Space-Track as an OMM object, epoch Nov 8, 2026, 6:00 AM, 12 hours old.
{
"OBJECT_NAME": "TOPO 1",
"OBJECT_ID": "1970-025B",
"EPOCH": "2026-11-08T06:00:17.205696",
"MEAN_MOTION": 13.46704427,
"ECCENTRICITY": 0.00022044,
"INCLINATION": 99.8824,
"RA_OF_ASC_NODE": 224.112,
"ARG_OF_PERICENTER": 22.6856,
"MEAN_ANOMALY": 129.2189,
"EPHEMERIS_TYPE": 0,
"CLASSIFICATION_TYPE": "U",
"NORAD_CAT_ID": 4363,
"ELEMENT_SET_NO": 999,
"REV_AT_EPOCH": 78058,
"BSTAR": 0.000033772184,
"MEAN_MOTION_DOT": -2.4e-7,
"MEAN_MOTION_DDOT": 0
}