QB50 precursor amateur radio operator page

Welcome to the amateur radio operator page for the QB50 precursor missions. This mission is comprised of two satellites: QB50p1 and QB50p2

After deployment from the Quadpack, the satellite will be transmitting its CW beacon.

Contact information / reception reports

To get in touch with the operations team please use the following email This email address is being protected from spambots. You need JavaScript enabled to view it. and This email address is being protected from spambots. You need JavaScript enabled to view it. To upload the received data please follow this link: upload.qb50.eu

We would appreciate to receive reception reports or recordings of the downlink signal, please include the following information in your report:

  • Name and callsign
  • Location or Maidenhead gridsquare locator
  • Date and time of reception (UTC)
  • Frequency at which you have received a QB50 precursor satellite
  • Which of the two satellite you think you have heard
  • Satellite transmission mode (indicate whether you have received a CW beacon or AX.25 beacon or both)

 We will also be present in the #cubesat channel on the Freenode IRC network (irc.freenode.net)

Satellite downlink overview

  • QB50p1 downlink frequency: 145.815 MHz
  • QB50p2 downlink frequency: 145.880 MHz
  • Satellite antenna polarization: linear

CW / Morse beacon

  • Modulation: CW / Morse code
  • Speed: 15 words per minute
  • Beacon interval: 45 seconds
  • Beacon length: approx. 12 seconds

CW beacon content















  • ID: character to determine satellite ID
  • X: character in the range A-Z
  • Y: character in the range A-Z or number in the range 0-9

You can use the CW beacon content decoder to translate the CW beacon characters to engineering values. 

AX.25 beacon

  • Modulation: Binary Phase Shift Keying (BPSK)
  • Nominal data rate: 1200 bps (2400bps, 4800bps, 9600bps are possible upon ground command)
  • Protocol: AX.25 UI frames
  • Enoding: NRZI
  • Beacon interval: 10 seconds
  • QB50p1 AX.25 callsigns:
    • FROM: QB50P1-0
    • TO: QB50P1-0
  • QB50p2 AX.25 callsigns:
    • FROM: QB50P2-0
    • TO: QB50P2-0

You can use the AX.25 beacon content decoder to translate the nominal mode beacon content to engineering values. Please note that the a beacon consists of two AX.25 frames, both of which are defined in the content decoder.

Transponder information

The transponders will be activated after main mission completion


QB50p1 carries the FUNcube-3 400 mW inverting linear 435/145 MHz transponder provided by AMSAT-NL with support from AMSAT-UK.

    Uplink: 435.035-435.065 MHz LSB
    Downlink: 145.935-145.965 MHz USB


QB50p2 carries a 435/145 MHz FM transponder and FX25 data transmitter from AMSAT-Francophone.

    Uplink: To be announced
    Downlink: 145.840 MHz 9600 bps FSK FX25



The QB50 Precursor Flight

QB50p1 and QB50p2 are currently in orbit. If you wish helping downloading data and telemetry, please go to this web page.

A monumental highlight of the QB50 project is approaching very quickly. By June 2014, the first two satellites of the project will be launched into orbit. A large part of the consortium has contributed to the design and manufacturing of our Precursor satellites.




Developing and launching CubeSats into orbit typically involves higher risks compared to classical, commercial or governmental, missions. This is due to the use of cost-efficient components and often due to the educational character of such projects. This was not enough for QB50 and hence, we insisted that key subsystems of the mission are being tested, de-risked as we say, in orbit before we use them on the main mission. In addition, the campaign serves as an end-to-end rehearsal for the involved engineers and managers. All of this will enable the consortium to provide flight proven technology, optimally manage the main mission and to support QB50 community with hand-on experience.

For this purpose two 2-Unit CubeSats will be built, launched and operated by the QB50 consortium. As part of the precursor risk-reduction campaign, the newly developed deployment system will be qualified and used to deploy the two QB50 precursor satellites. The deployment system consist out of a 3-Unit QuadPack (that has a total of 12-Units of launch capacity in 4 individually controlled launch-tubes and the associated deployment sequencing electronics. This activity derisks: 

  • The QuadPack CubeSat deployer and its electronics, which form the main building blocks for launching the 50 QB50 satellites is an essential building block in the provision of affordable access to space. The ground qualification and subsequent demonstration during the precursor flight, will provide heritage for the deployment system and provides a flight tested system for the main flight.  
  • The launch campaign itself will allow the launch team and all other involved consortium members involved in the launching of the QB50 precursor satellites to gain experience from a modest launch campaign and draw valuable lessons from this activity for the main flight. 




The development of the two satellites is currently ongoing at the ISIS premises in Delft. The first satellite (QB50p1) will carry an INMS payload and the second satellite (QB50p2) will carry a FIPEX payload. Furthermore both satellites will carry a thermocouple experiment from VKI and an amateur radio payload provided by the AMSAT-ML and AMSAT-FR. These last payloads serve as a return favour to the satellite radio amateur community for the fact that the QB50 main mission can use the amateur bands during the full flight in 2016. Lastly, the satellites will fly the SSC provided ADCS system that is available for the QB50 flight. The satellites will be delivered for launch at the beginning of Q2 2014. 


 Flying these satellites allows the consortium to de-risk a number of elements including: 

  • The developed payloads as the payloads will be flown and tested on-orbit,
  • The ADCS system as its performance will be tested on orbit,
  • The satellite development as it provides proof and a reference to a QB50 capable satellite design.

The operations of the satellites will also be performed in a similar way as for the QB50 main flight operations, which means that payload tasking will be performed by MSSL and implemented by mission control. This will largely be representative of how a significant amount of QB50 teams will operate their satellites for the main flight. Furthermore, the option of implementing the EPFL SCS is planned to be tested later in the precursor mission, which would also validate the data path for the teams that use this system in their baseline QB50 mission. Performing operations like this de-risks:

  • The interface between the payload and the ground segment
  • The interface between a typical ground station and the central payload data server
  • The interface between an EPFL SCS ground station and the central payload data server

All in all, the precursor flight will provide everyone with a boost of confidence for the QB50 main flight!

The consortium has finalized the detailed design phase in December 2013 for two 2-unit cubesats. We have convened the 16th of January 2014 at ISIS premises to conclude that all hardware is available and to commence the assembly and testing activities. 

Ultimately, the Precursor satellites will be launched by a Russian Dnepr rocket into a near Sun Synchronous Orbit at 624 km altitude, now scheduled for 19th June 2014. For 6 months, we will then operate and test all subsystems. Afterwards, we will hand-over the satellites to the radio amateur community.

"The QB50 precursor satellites are designed with the help of ESATAN-TMS. The high-fidelity modelling allows confirming the compatibility to the thermal environment. ITP Engines UK is kindly supporting QB50 with the licenses for the thermal analysis and simulation software ESATAN-TMS."


 Edited by J. Rotteveel, J. Elstak and J. Thoemel