- Earth-watching satellite
- IRS 1B
- NORAD 21688
- 1991-061A
- Low Earth orbit
Current orbit
View on live mapOrbit began over the Indian Ocean
Orbit ends over the Atlantic Ocean
In view from you
Nobody watches IRS-1B 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 IRS-1B, 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
- Close approach
On Saturday, Oct 24 at 2:16 AM UTC, a fragment of THOR Ablestar (NORAD 138) was to pass within 104 m of IRS 1B (NORAD 21688). The chance was about 1 in 3,000.
Summary
Over the Pacific Ocean LIVE
Where is IRS-1B?
At 5:39:18 PM UTC IRS-1B was over the Pacific Ocean (52.9° S, 179° E), 924 km up, moving at 7.39 km/s and in sunlight.
What is IRS-1B?
A satellite that watches the Earth in low Earth orbit, in space since Aug 29, 1991.
Can I see IRS-1B?
No, not with the naked eye: no brightness has been published for IRS-1B, and nothing here estimates one; what people use is its pictures and measurements of the Earth.
General
- Operator
- Indian Space Research Organization
- State
- India, Republic of
- Built by
- Indian Space Research Organization
- What it is
- Earth-watching satellite
- Launched
- Mass
- 990 kg
- Operating
- 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
- 5:39 PM UTC
- Station time (UTC)
- 5:39 PM UTC
- Latitude / longitude
- 52.9° S, 179° E
- Altitude
- 924 km
- Speed
- 7.39 km/s (26,593 km/h)
- Course
- south
- Light
- In sunlight
- Inclination
- 99.4°
- Orbital period
- 103 minutes
- Orbits per day
- 13.98
- This orbit
- 881 to 916 km
- In shadow
- None of this orbit
- In view from
- Within 2,300 km of the point below it
- Elements epoch
- Nov 8, 2026, 6:16 AM, 11 hours old
- Source
- Position from Space-Track orbital elements of Nov 8, 2026, 6:16 AM, 11 hours old.
No operator publishes an ephemeris for IRS-1B, so every position here comes from its orbital elements.
In orbit
- Close approaches
- 1 reported. No close approach to IRS-1B is reported for the next three 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
IRS-1B shares its launch, 1991-061, with one other body the catalogue lists in orbit.
| Body | What it is |
|---|---|
| SL-3 R/B | Rocket body |
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 |
|---|---|---|---|---|
| IRS-1B | 881 to 916 km | 103 minutes | 990 kg | 1991 |
| Sentinel-5P | 826 to 828 km | 101 minutes | 820 kg | 2017 |
| Suomi NPP | 825 to 829 km | 101 minutes | about 2.1 t | 2011 |
| MetOp-SG A1 | 820 to 821 km | 101 minutes | about 4 t | 2025 |
| Metop-B | 818 to 823 km | 101 minutes | about 4.1 t | 2012 |
| Metop-C | 820 to 821 km | 101 minutes | about 4.1 t | 2018 |
Data and API
The current elements from Space-Track as an OMM object, epoch Nov 8, 2026, 6:16 AM, 11 hours old.
{
"OBJECT_NAME": "IRS 1B",
"OBJECT_ID": "1991-061A",
"EPOCH": "2026-11-08T06:16:57.626976",
"MEAN_MOTION": 13.97893726,
"ECCENTRICITY": 0.00240192,
"INCLINATION": 99.4115,
"RA_OF_ASC_NODE": 323.8092,
"ARG_OF_PERICENTER": 334.0566,
"MEAN_ANOMALY": 36.5551,
"EPHEMERIS_TYPE": 0,
"CLASSIFICATION_TYPE": "U",
"NORAD_CAT_ID": 21688,
"ELEMENT_SET_NO": 999,
"REV_AT_EPOCH": 68862,
"BSTAR": 0.00019810489,
"MEAN_MOTION_DOT": 0.00000234,
"MEAN_MOTION_DDOT": 0
}