- Earth-watching satellite
- SSTL S1-4
- NORAD 43618
- 2018-071A
- Low Earth orbit
Current orbit
View on live mapOrbit began over Russia
Orbit ends over Russia
Sunlit since
Enters the Earth’s shadow
In view from you
Nobody watches S1-4 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 S1-4, 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 the Pacific Ocean LIVE
Where is S1-4?
At 6:20:53 PM UTC S1-4 was over the Pacific Ocean (10.8° S, 143.3° W), 579 km up, moving at 7.57 km/s and in sunlight.
What is S1-4?
A satellite that watches the Earth in low Earth orbit, in space since Sep 16, 2018.
Can I see S1-4?
No, not with the naked eye: no brightness has been published for S1-4, and nothing here estimates one; what people use is its pictures and measurements of the Earth.
General
- Operator
- Surrey Satellite Technology Ltd/Astrium
- State
- United Kingdom of Great Britain and Northern Ireland
- Built by
- Surrey Satellite Technology Ltd/Astrium
- What it is
- Earth-watching satellite
- Launched
- Mass
- 444 kg
- Operating
- Yes
- 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, the launch day, the mass, and whether it is operating. The orbit class is read from its current elements.
Latest orbital data
- Position received
- 6:20 PM UTC
- Station time (UTC)
- 6:20 PM UTC
- Latitude / longitude
- 10.8° S, 143.3° W
- Altitude
- 579 km
- Speed
- 7.57 km/s (27,245 km/h)
- Course
- north
- Light
- In sunlight until 6:48 PM UTC
- Inclination
- 97.5°
- Orbital period
- 96 minutes
- Orbits per day
- 14.99
- This orbit
- 556 to 574 km
- In shadow
- 31 minutes of each orbit
- In view from
- Within 1,720 km of the point below it
- Elements epoch
- Nov 8, 2026, 7:11 AM, 11 hours old
- Source
- Position from Space-Track orbital elements of Nov 8, 2026, 7:11 AM, 11 hours old.
No operator publishes an ephemeris for S1-4, so every position here comes from its orbital elements.
In orbit
- Close approaches
- No close approach to S1-4 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
S1-4 shares its launch, 2018-071, with 2 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 |
|---|---|---|---|---|
| S1-4 | 556 to 574 km | 96 minutes | 444 kg | 2018 |
| WorldView-3 | 612 to 615 km | 97 minutes | about 2.8 t | 2014 |
| PAZ | 507 to 510 km | 95 minutes | about 1.4 t | 2018 |
| SAOCOM 1A | 622 to 624 km | 97 minutes | about 3 t | 2018 |
| ALOS-2 | 630 to 632 km | 97 minutes | about 2.1 t | 2014 |
| SMAP | 681 to 683 km | 98 minutes | 944 kg | 2015 |
Data and API
The current elements from Space-Track as an OMM object, epoch Nov 8, 2026, 7:11 AM, 11 hours old.
{
"OBJECT_NAME": "SSTL S1-4",
"OBJECT_ID": "2018-071A",
"EPOCH": "2026-11-08T07:11:08.333664",
"MEAN_MOTION": 14.99497438,
"ECCENTRICITY": 0.00129425,
"INCLINATION": 97.4752,
"RA_OF_ASC_NODE": 177.9706,
"ARG_OF_PERICENTER": 117.4687,
"MEAN_ANOMALY": 242.7855,
"EPHEMERIS_TYPE": 0,
"CLASSIFICATION_TYPE": "U",
"NORAD_CAT_ID": 43618,
"ELEMENT_SET_NO": 999,
"REV_AT_EPOCH": 44450,
"BSTAR": 0.000085343731,
"MEAN_MOTION_DOT": 0.00000992,
"MEAN_MOTION_DDOT": 0
}