What is the RS81S downlink frequency?

RS81S transmits on 435.650 MHz (FSK 38k4) and 435.200 MHz (FSK 38k4).

When does RS81S pass over my location?

Open RS81S on the live map and enter your Maidenhead locator or use GPS: the tracker lists the passes of the next 24 hours with AOS, maximum elevation and LOS, and shifts the frequencies for Doppler.

RS81S

HORS 3 · amateur radio satellite, NORAD 61753

Not heard today

Modes Digi Orbit LEO, 92 min

Track RS81S on the live map Find it in the sky

Next passes over your station

Pass times depend on where you are. Track RS81S on the live map to see its next passes over your station.

RS81S frequencies

Uplink	Downlink	Beacon	Mode
—	435.650 MHz	—	FSK 38k4
—	435.200 MHz	—	FSK 38k4

Nominal frequencies, without Doppler. The live map shifts them for your station during a pass. Frequencies: SatNOGS DB (modified: working amateur transmitters only, in MHz), CC BY-SA 4.0.

Status

Listed as working, but nobody reported hearing RS81S on AMSAT in the last 30 days.

From reports filed on AMSAT, last 30 days.

Orbit

Type	Low Earth orbit
Altitude	366–375 km
Inclination	97.3°
Period	92.0 min
TLE epoch	2026-10-28 15:31 UTC

Orbital elements: CelesTrak, checked every 3 hours.

Questions about RS81S

What is the RS81S downlink frequency?: RS81S transmits on 435.650 MHz (FSK 38k4) and 435.200 MHz (FSK 38k4).
Is RS81S active?: Listed as working, but nobody reported hearing RS81S on AMSAT in the last 30 days.
When does RS81S pass over my location?: Open RS81S on the live map and enter your Maidenhead locator or use GPS: the tracker lists the passes of the next 24 hours with AOS, maximum elevation and LOS, and shifts the frequencies for Doppler.