CHESS will not have an amateur payload

CHESS CubeSat - Credit EPFL Spacecraft Team

CHESS CubeSat – Credit EPFL Spacecraft Team

Two CHESS CubeSats had been planned to carry amateur radio linear transponders, however, it was announced on June 10, 2021, there will not be any amateur payload on the satellites.

A translation of the press release reads:

The CHESS project management, due to funding constraints, had to move the project towards a commercial cubesat platform. Space is scarce on this new platform to accommodate another payload. Subsequently, there is no longer an opportunity to carry a ham radio transponder on board.

The CHESS project management has correctly decided not to use frequencies in the amateur satellite service and to use earth exploration or experimental UHF- and X- band frequencies.

The ham community, who assured the funding of the transponder, is very disappointed by this decision, but must accept it.

Such projects always carry risks of one partner changing its mind. That is what happened here.

Many thanks to all who have actively supported the transponder project, especially the AMSAT-UK and AMSAT-NL team.

AMSAT-HB announcement

January 2021 project announcement

CHESS CubeSat Constellation to carry FUNcube transponders

CHESS CubeSat - Credit EPFL Spacecraft Team

CHESS CubeSat – Credit EPFL Spacecraft Team

In 2020, a project between AMSAT-UK, AMSAT-NL and Swiss universities started with the aim of equipping two Swiss satellites with a linear transponder for amateur radio.

CHESS - Three Unit CubeSat

CHESS – Three Unit CubeSat

With a linear transponder, several QSOs can take place simultaneously. The satellites can be operated in CW/SSB with the simplest equipment. The satellites also include features for classroom demonstrations and experiments. In numerous teleconference discussions, the technical possibilities could be sounded out and the realisation prepared.

The CHESS [Constellation of High Energy Swiss Satellites] project includes two satellites, which will be built simultaneously and later launched as a constellation. Both will provide a linear transponder for amateur radio use. The first satellite will have a nearly circular orbit at an altitude of 400 km. The second will have an elliptical orbit with an altitude of 350×1000 km.

The satellites themselves are a project of the École polytechnique fédérale de Lausanne (EPFL) with support from the Lucerne University of Applied Sciences and Arts (HSLU – Institute of Electrical Engineering IET), the University of Bern, the Valais University of Applied Sciences and Arts (HES-SO), the Haute École Neuchâtel and the Swiss Federal Institute of Technology ETH Zurich. The amateur radio payload is a project of AMSAT-UK/-NL.

On 18 December 2020, the successful system requirements review took place. The project coordination between CHESS and AMSAT lies with the Amateur Radio Association of the Lucerne University of Applied Sciences and Arts – Technology & Architecture, Horw.

The Swiss AMSAT Operators provide information about the CHESS project at

EPFL Spacecraft Team

CHESS - Three Board Stack

CHESS – Three Board Stack