SERPENS CubeSat Deployed from ISS

Deployment of the SERPENS CubeSat from the ISS on September 17, 2015 - Credit JAXA

Deployment of the SERPENS CubeSat from the ISS on September 17, 2015 – Credit JAXA

On September 17, 2015 the Brazilian SERPENS CubeSat carrying an amateur radio payload, call sign PY0ESA, was deployed from the International Space Station (ISS).

SERPENS LogoSERPENS is a 3U CubeSat which was developed by students at the University of Brasilia and focuses on meteorological data collection.

The SERPENS Amateur Radio Page shows these downlink frequencies:

•  145.980 MHz using GFSK modulation at 9600 bps and AX.25 protocol transmiting two different beacons. The first occurs every 10 seconds with the message “SERPENS A”. This is implemented for easy identification of the satellite when searching for it. The second beacon is transmitted every 30 seconds and contains the main housekeeping data of the satellite. In addition to the beacons, a simple Store and Forward experiment has been implemented.

437.365 MHz using CW/MSK modulation at 1200 bps and CSP protocol.



There is a Store and Forward messaging system compatible with HUMSAT sensors on the frequency of 437.525 MHz, using GMSK modulation at 1200 bps. The HUMSAT transponder will collect data (e.g. wind, humidity, water levels, etc) from Earth based sensors operating on 437.525 MHz, store the data on-board and then transmit it to university ground stations. For more information visit

SERPENS carries a Pulsed Plasma Thruster for CUbesat Propulsion (PPTCUP) unit developed by UK companies Mars Space Ltd and Clyde Space Ltd in collaboration with the University of Southampton.

PPTCUP Board - Credit Mars Space Ltd

PPTCUP Board – Credit Mars Space Ltd

The PPTCUP consists of a thruster board and discharge chamber. Overall, the thruster assembly weighs 180 grams including 7g of Teflon fuel and delivers a thrust of 40 micronewtons at a power consumption of 2 Watts. The entire thruster assembly fits into a 90 by 90 by 27-millimeter envelope.The thruster operates at a specific impulse of 608 seconds and in its original version is certified for 1.5 million shots. For durability, the system uses copper-tungsten electrodes. All thruster functions are controlled by a PIC16 microcontroller.

Also deployed with SERPENS from the ISS was the CubeSat S-CUBE designed to observe the Ultraviolet (UV) spectrum during the Orionid meteor shower in October. It does not operate in the Amateur Satellite Service.

SERPENS Amateur Radio Page

SERPENS information in HTV-5 Cargo Overview

Artists impression of Kibo Robot Arm CubeSat Deployment

Artists impression of Kibo Robot Arm CubeSat Deployment