UNNE-1B

News · 13 Oct

UNNE-1B is transmitting

The community is receiving its first packets, including the Nebrija game ones.

Report · 1 Oct

Successful launch

Falcon 9 puts 130 payloads into orbit, including the first Spanish OTV.

The challenge

Mission Space Cowboy II

A lost spacecraft, an encrypted message and a knowledge pill every week.

The mission

From the rocket to orbit

UNNE-1B does not leave the rocket directly: it travels inside OSSIE-D, the first Spanish orbital transfer vehicle (OTV), which released it in early October.

1

1 Oct · 20:32 ✓

Launch

Successful lift-off of a SpaceX Falcon 9 from Vandenberg (California) on the Transporter-18 mission.

2

1 Oct · ~21:32 ✓

OTV deployment

One hour after lift-off, Falcon 9 releases OSSIE-D, built by the Galician company UARX, with UNNE-1B and HADES-L inside. It is already transmitting.

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First signals · 4 Oct ✓

Release and deployment

OSSIE-D releases the satellite, which deploys its antenna and starts sending telemetry on 436.888 MHz.

4

After testing · in progress

Repeater on

AMSAT-EA switches the repeater on by telecommand. From then on it will be permanently available.

How the launch went

Times in Spanish mainland time (CEST, UTC+2). Lift-off took place 14 minutes after the originally planned time (20:18).

Read the report →

Date: Thursday 1 October 2026
Lift-off: 20:32 Spain · 11:32 California · 18:32 UTC
Result: Successful launch; OSSIE-D in orbit and transmitting
Launch site: SLC-4E, Vandenberg Space Force Base (California, USA)
On board: 130 payloads: cubesats, microsats and 4 orbital transfer vehicles, including OSSIE-D
First stage: B1082, 25th flight; landed at Vandenberg's Landing Zone 4

T−0 · 20:32Falcon 9 lift-off
T+1 minMaximum aerodynamic pressure (Max Q)
T+2 min · 20:34First and second stage separation
T+3 minFairing separation: the payload is exposed
T+7 min · 20:39First stage lands at Vandenberg
T+8 min · 20:40Second stage reaches orbit
T+54 min · 21:26Satellite deployment begins, 520 km up
T+1 h 00 min · 21:32OSSIE-D separates, with UNNE-1B inside
4 OctFirst UNNE-1B receptions in the registry

Sources: SpaceX · Transporter-18 Mission (event sequence) and Next Spaceflight (actual lift-off time). Times after lift-off are approximate.

UNNE-1B is a satellite operated by AMSAT-EA carrying a payload developed at Nebrija University in Madrid.

It shares the ride with HADES-L, another AMSAT-EA satellite with an HF-to-UHF voice repeater and a materials experiment. Because of power limits, the HADES-L repeater only works 4 minutes out of every 12; the UNNE-1B repeater will always be on once enabled.

After launch the transponder is off (mode 0) and is switched on by telecommand when the satellite is ready.

A deduction game in orbit

On board there is an Arduino board running a deduction game programmed by the ARIES group at Nebrija University. The satellite regularly sends its own telemetry packet (type 10) with the game status and the number of weeks since it was released.

Receiving and decoding those packets from the ground is the starting point of the Space Cowboy II challenge.

Frequencies

How to listen to UNNE-1B

All you need to listen is an inexpensive SDR receiver and a 70 cm antenna. Talking through the repeater requires an amateur radio licence.

Downlink · satellite → ground

436.888 MHz

UHF · 70 cm band · what you receive at home

FM voice FSK 200 bps (up to 2400) Telemetry

Uplink · ground → satellite

145.925 MHz

VHF · 2 m band · licence required

FM voice, no subtone FSK 200 bps AFSK · AX.25 APRS 1200 / 2400

Transponder modes

0

Off

Default state after launch. Only the satellite telemetry is transmitted.

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FM repeater

Relays FM voice and FSK / AFSK data (AX.25, APRS) up to 2400 bps. Carrier-activated, no subtone.

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Regenerative digital repeater

Receives FSK packets, rebuilds them digitally and retransmits them clean, from 50 to 2400 bps.

First time? The Radio module explains step by step how to receive a satellite with an RTL-SDR, and the Signals module explains FSK modulation.

Transmissions

What the satellite transmits

UNNE-1B sends FSK packets in 30-second slots that tell how it is doing: power, temperatures, sun sensors, position… and the Nebrija game.

01 Power

02 Temperatures

03 Satellite status

04 Power statistics

05 Temperature statistics

06 Sun sensors

08 Antenna deployment

09 Extended power

10 Nebrija University game

12 Ephemeris (position)

14 Time series (90 min)

15 CODEC2 digital voice

Link specifications

Modulation: FSK · 1125 Hz tone spacing
Data rate: 200 bps (up to 2400 bps)
Sync word: 0xBF35 · address «C»
Scrambler: G(x) = x¹⁷ + x¹² + 1
Error check: CRC-CCITT-FALSE (0x1021)
Bit order: MSB first

Full packet format: UNNE-1B transmissions overview (AMSAT-EA, PDF). Updates and ground station software at amsat-ea.org/proyectos.

Educational platform

Learn with UNNE-1B

Everything you need to understand how a satellite communicates, with no prior knowledge.

MODULE 01

Who makes it possible

The mission team

Payload

Nebrija University

The ARIES group of the Higher Polytechnic School, author of the game on board.

Operator

AMSAT-EA

Spanish amateur satellite association. Builds and operates UNNE-1B.

Orbital transfer

UARX

Spanish company behind the OSSIE OTV, which releases the satellite in orbit.

Launcher

SpaceX

Falcon 9, Transporter-18 rideshare mission.

UNNE-1B follows in the footsteps of UReSat-1 «Antonio de Nebrija» (SO-120), in orbit since 2023.