Measured data from experiments (payload) are available in this section:

The detailed analysis revealed the problem in the software code that caused the communication failure. Unfortunately, we are not able to restore it remotely. For this reason, we decided to launch the backup BDSAT-2 in SPACEX’s Transporter 6 mission in autumn 2022.
After that, all measurements and also functions for radio amateurs will be restored.

This project is implemented with financial support from the state budget through the Ministry of Industry and Trade in TRIO program.

Nanosatellite supporting the world radio amateur community

BDSAT project aims to support the radio amateur community with several HAM services and activities. Secondary goal is a verification of a prototype of pressure measuring equipment and to verify the functionality of this technology in open space conditions. The function of the measurement itself, its feasibility and suitability for use in satellites in space conditions will be verified. The second part of the technological experiment is to verify use of supercapacitors as a modern approach to energy storage in satellites.

BDSAT is a satellite built for radio amateurs. Creators and supporters of BDSat project have great passion for space radio amateur activities and are already involved in two radio amateur mission from the region, skCUBE and GRBAlpha. Both of them very successful and popular in the community.

so-called the Cubesat

BDSAT is the nanosatellite, so-called the Cubesat, sized 10x10x10 cm. Nanosatellite space technology is a major technological trend.

Despite their small size and weight, Cubesats are taking over some roles of the larger satellites as it is a low-cost option for developing and testing new technologies in space.

The BDSAT project is divided into two parts. First at all, it will test BD SENSORS pressure transmitters in open space conditions. These transmitters have to meet very demanding requirements both in terms of survival in harsh space conditions and in terms of maintaining accuracy and other technical parameters. The reliability of the technology is essential to the future space applications.

A base station for communication with the satellite will be located at the co-investigator CEITEC VUT, which will provide the command and data collection from the satellite.

The experiment also includes verifying the function of the supercapacitor bank. It is a powerful source for storing electricity for satellite systems. In the future, a supercapacitor bank can replace conventional battery power systems. The system will be charged with energy from solar panels during the flight phase facing the Sun. During the second phase of the flight without the power from the solar panels, the energy from this source will be discharged to an artificial load.

The long-awaited launch of the BDSAT satellite will take place in April! We will inform you about the details of this event in time. The time until the satellite is launched into orbit on this page is only indicative.

Photo: interior of the rocket with attached BDSAT

After launching the nanosatellite into an orbit, regular monitoring and data collection will take place to check the proper functioning of the pressure sensor and the supercapacitor´s bank, their temperature dependence, and degradation influenced by the time and radiation.

The supercapacitor’s bank will also be assessed for the ability to maintain energy in space. In addition to data from verification experiments, operational data of nanosatellite will be monitored.

Printed circuit boards for the Engineering model (EM) are currently being installed. On this model of the BDSAT cubesat, all the functionality of the proposed satellite concept will be tested. In this phase of development, we are able to detect possible errors before building your own satellite flying into the universe.

EM is built according to the same procedures as the resulting flight model (so-called Flight model – FM), but it is not intended to be launched into space. This model serves only as a training unit, which is used for testing, for example, the assembly of individual components into the final unit, the functionality of HW and many other things that are better to be tested just before launching an expensive flight model. It will also be very important to test the software of the on-board computer controlling and coordinating all satellite activity.

For radio-amateurs

BDSat HAM info

HAM services provided by BDSAT

  • AX25 telemetry
  • CW beacon
  • Digipeater
  • Anniversary/special occasions AX.25 & CW messages for community engagement
  • SATNOGS integration, decoder, dashboard

We would like to express our gratitude to the Czech Telecommunication Office and International Amateur Radio Union for making this mission possible.

The satellite carries a set of two Murgas transceivers from Spacemanic.

Basic information for satellite reception

  • Callsign: OK0BDS
  • UHF Downlink frequency: 436.025 MHz +/- Doppler shift
  • VHF Downlink frequency: 145.850 MHz +/- Doppler shift
  • Modulation: GFSK, CW
  • Encoding: G3RUH 9k6 bd
  • Protocol: AX.25
  • Transmitting power: 1 W (30dBm)
  • Onboard antenna: Dipole
  • Antenna polarization: Linear



MYCALL [Your call sign]

UNPROTO CQ (or callsign)

Orbital parameters / Preliminary TLE

Orbit: 500km SSO, 11:00 LTDN

1 12345U 22999A 22091.73697910 .00000000 00000-0 00000-0 0 00005 
2 12345 97.4200 174.2485 0018409 214.8262 199.3703 15.24239762000000

SATNOGS Integration

Satnogs DB Link: SatNOGS DB – BDSat

Satnogs Network Observations: SatNOGS Network – Observations

Satnogs Dashboard: Satellite Telemetries – Grafana (

Message types

  1. AX.25 TRX beacon packet
  2. AX.25 OBC beacon packet
  3. AX.25 message
  4. CW data beacon
  5. CW message beacon
  6. Ground Station communication

Transmission interval

The packet and CW transmission intervals are following:

  • obc ax25 beacon every 90s (uhf)
  • trx uhf ax25 beacon every 60s
  • trx uhf ax25 message every 300s
  • trx vhf ax25 beacon every 180s
  • trx uhf morse beacon every 180s

There are offsets applied between transmissions.

Example of decoded AX.25 TRX beacon packets

Data in AX.25 TRX beacon packet values are comma-separated.

1:Fm OK0BDS To CQ  [02:32:31R] [AA] [+++++++] 
1:Fm OK0BDS To CQ  [02:32:36R] [AA] [++++++-] 
1:Fm OK0BDS To CQ  [02:32:56R] [AA] [+++++++] 


  1. uptime since reset [in seconds]
  2. uptime total [in seconds]
  3. Radio DL resets [count]
  4. Radio DL MCU act. temperature [0.01°C]
  5. RF chip act. temperature [0.01°C]
  6. RF power amplifier act. temperature [0.01°C]
  7. digipeater forwarded message count
  8. last digipeater user sender’s callsign [ASCII, 6 spaces means nobody yet]
  9. RX data packets (AX25 with CRC matched, includes CSP and digipeater packets)
  10. TX data packets (includes CSP and digipeater packets)
  11. actual RSSI, ((value / 2) – 134)[dBm]
  12. Value of RSSI when carrier detected – after preamble ((value / 2) – 134)[dBm]

Note: [0.01C] means e.g. -1234 -> -12.34C

Example of decoded AX.25 OBC beacon packets

OBC packet is created by Spacemanic Eddie Onboard Computer including selected interesting values from BDSat onboard subsystems. Values are comma-separated.

1:Fm OK0BDS To CQ  [13:10:39R] [AA] [+++++++]



  1. OBC – Packet identification
  2. rst – OBC reset number
  3. uptime – Current uptime since last reset [s]
  4. bat – Measured battery voltage [mV]
  5. temp – OBC temperature [0.01°C]
  6. tempZn – Solar panel Z- temperature [0.01°C]
  7. tempXp – Solar panel X+ temperature [0.01°C]
  8. tempYp – Solar panel Y+ temperature [0.01°C]
  9. tempYn – Solar panel Y- temperature [0.01°C]
  10. tempXn – Solar panel X- temperature [0.01°C]
  11. freemem – OBC free memory [512B]
  12. pldState – Payload state
  13. pldProg – Payload program number
  14. pldHwState – Payload hardware state
  15. psuUptime – Uptime of Power Supply Unit [s]
  16. CRC code

Example of decoded AX.25 message beacon packet

1:Fm OK0BDS To CQ  [02:32:33R] [AA] [+++++++]
BDSAT AX.25 test message for radio amateurs: Hello Space!

Example of CW data beacon

According to radio amateur standards, every CW beacon (no matter if data or message beacon) starts with "DE ok0bds = " and ends with "ar".

de ok0bds = u5433r126t29p30 ar


  1. Total uptime [minutes]
  2. DL resets
  3. Temp MCU [*C]
  4. Temp DL Radio PA [*C]

u5433 = Uptime 5433 minutes
r126 = 126 resets of downlink radio
t29 = 29 degree of Celsius on DL radio MCU
p30 = 30 degree of Celsium on DL radio PA

Example of CW message beacon

de ok0bds = morse test from earth ar

Link for sending of your reports