Communications & Radioamateurs

+++ NEW FREQUENCY +++

Due to an unscheduled factory reset of the radio, ABCS is now transmitting at 437.425 MHz with a reduced power level.

We are working to take it back to the original configuration. In the meantime, please tune into the new frequency.

ABCS TLE

1 53107U 22080C 22196.31595537 -.00000003 00000+0 00000+0 0 9998

2 53107 70.1247 76.7799 0016951 257.6053 272.3612 6.42318967 14

(updated on July 16, 2022)

This new TLE have been calculated according to radio amateurs observations. ASTROBIO is probably object 2022-80C, NORAD ID 53107

Where is ABCS now

Ground Station Operations

ABCS will communicate with the Ground Station at the School of Aerospace Engineering in Rome, which receives telemetry and data and send uplink commands, and will be open to the radioamateurs net. The ground station registered ID is IU0SIA.

ABCS has been registered to Space Assigned Numbers Authority (SANA) with the following ID:

• Oid: 1.3.112.4.7.1388

• Name: AstroBio CubeSat

• Abbreviation: ABC

• Aliases: ['AstroBio']

• Operating Location: Near Earth

• Simulator: False

• Family: Cubesat (OID only)

• Protocols: Other

• Other Protocols: ['AX25']

All the data sent by the satellite will be clear and public and the instructions for the interpretation of the raw telemetry data will be given to the radio-amateur community thus each radio-amateur will be able to autonomously decode the data he received.

ABCS mission will actively involve the radio-amateur community in order to provide an efficient download of the data.

To download the ABCS GUI, click the following button:

Astro Bio Cube Satellite Communications

ABCS orbit will be at about 5900 km of altitude with 70° of inclination, which means that ABCS will spend most of the time inside the inner Van Allen Belt, with deadly radiation levels (mostly protons). As a consequence, the expected mission lifetime is pretty short and also error-free operation would be not very likely.

For this reason, we are trying to involve as many people as possible to try to receive the signal of ABCS. The satellite operates on the amateur radio frequencies in the UHF band at the IARU coordinated frequency of 435.600 MHz.

ABCS hosts a ham digipeater which is active by default and can be accessed by any radioamateur. Instructions for the use of the digipeater are reported below.

In addition, any radio amateur is invited to receive the satellite telemetry and share it at his will. Instructions for decoding the telemetry data packets are reported below. Data received by the radio-amateur community around the world will be collected and sorted along with data downloaded by the Ground Station of the School of Aerospace Engineering. All the data will be available for free consultation online and all the contributors will be acknowledged.

Radio Link

• Radio Frequency Band: UHF

• Downlink Frequency: 435.600MHz

• Uplink Frequency: 435.600 MHz

• Modulation:9600 baud FSK

• Encoding: G3RUH

• Protocol: ax.25

ABCS Beacon

ABCS sends periodic beacon messages containing status and telemetry information as well as payload data.

There are three types of beacon messages with the same length of 235 bytes. The three beacons are sent cyclically. The beacon interval is 10s by default but can vary from 5s to 15s according to the satellite operational mode and status.

The beacon type (00, 01, 02) is reported in the tenth byte of the message (after the ax.25 header).

All the beacons contain a common time reference, the current op-mode and the mission phase.

Beacon type 00 - Memory and Payload-1

Beacon type 00 contains the information about the status of the on-board computer, the status of the storage and the execution state of the main payload (lab-on-chip) experiments.

The last part of the beacon contains a data packet (first half) of the executed lab-on-chip experiments.

Beacon type 01 - Sensors

Beacon type 01 contains most of the sensors’ telemetry and the information about on-board power system. The last part of the beacon contains a data packet (second half) of the executed lab-on-chip experiments.

Beacon type 02 - Electric Power System and Payload-2

Beacon type 02 contains detailed information about the on-board power system and radioamateur data. The last part of the beacon contains a data packet of the secondary payload experiments.

In Figure: ABCS complete beacon (link also here).

ABCS Digipeater

The satellite will reply to an incoming radioamateur packet by resending it to ground.

The last callsign of the last radioamateur that contacted the satellite is reported in the beacon message of the satellite (type 02).

Using the digipeater is extremely simple: To use the digipeater one just needs to send a valid ax.25 data packet starting with the keyword “HAM” followed by the message.

Example: "HAMHello world!!!"

ABCS will transmit: "CQHello world!!!"

The message length is limited to 140 characters to avoid overloading the satellite radio and cope with the limited power budget. For the same reason, a dead time of about 10 seconds is then applied before the next digipeater action is enabled. However, any contact in this time window will be counted and the callsign stored onboard and reported in the beacon.

The ABCS GUI allows to decode the demodulated packages and display relevant telemetry information in real-time. In addition, it allows to easily access the radioham digipeater.

The software can be interfaced with the radio/TNC hardware as well as to other softwares (gnuradio, HS_Soundmodem,...) using both serial and TCP interfaces.

The ABCS GUI runs under Windows (tested on Windows 7, Windows 10, Windows 11) and under Linux using Wine (tested on Ubuntu 20.4 LTS).

The GUI contains 4 main areas:

1. The values and widget area where the decoded beacon data are reported. Three beacons (one per each beacon type) are needed to display all the data

2. A graphs window where relevant information are plotted over time as soon as more data is available

3. Raw data and event messages window

4. Digipeater window

The zoomed area shows:

1. Folder icon to load the workspace

2. Setting icon to select the radio input

3. Start / stop button

GUI Initial Set-up

Steps to be followed when running the GUI for the first time. Note that there are two different inputs available in the GUI: user needs to select one the two inputs (Serial/TCP) and enter the right parameters in the settings and save it.

Step 1 - Load The Workspace File

Open the file “ABCS_HAM_workspace.gsiw” as shown in the image below. This file contains the various fields used to display the decode data.

In Figure: Loading the workspace for the first time.

STEP 2 - Connect the Radio/TNC/SDR

1. Settings can be opened by clicking the settings icon in the left side ribbon. Settings icon is disabled when the GUI is running.

2. In the connection mode there are two different types of connection that can be selected. Users can use either Serial Com or TCP according to their Radio connection.

In Figure: General settings tab.

STEP 2.a - Serial Connection Settings

Open the serial connection tab.

The various fields in the Serial Settings tab need to be verified to match the user's hardware. This is the most common configuration when using a TNC: in this case both normal TNC operation and KISS mode are supported, selecting the appropriate configuration in the Serial Mode drop down menu.

In KISS mode, the AX25 header is processed by the GUI and data are extracted from the packet payload. Without KISS mode, only the AX.25 payload data must be passed to the GUI discarding the AX25 header before doing that.

Please note that the serial baud rate refers to the connection with the Radio/TNC which may differ from the RF baud rate of 9600 baud.

Hit save when the configuration has been selected.

In Figure: Serial settings tab.

STEP 2.b - TCP Connection Settings

This configuration can be adopted when using an SDR and a gnuradio flowgraph for demodulating the message or similarly if SDR, SDR software (SDR Console, SDR#, HDSDR) and a sound modem (HS_Soundmodem) are used.

The following are the various fields available in TCP Settings.

1. 1. TCP Server address

   2. TCP Server port

   3. TCP Server maximum size (bytes)

Hit save when the configuration has been selected.

In Figure: TCP settings tab.

STEP 3 - Start the ABCS GUI

The user needs to click on the START/STOP button to open the connection to the radio using the configuration stored in the settings.

Please note that the selection of the serial COM port is done here: the list of the available COM ports appears close to the START button when clicking it, allowing to select the desired one.

Example - Using ABCS GUI with a SDR setup

In this section a practical usage example is reported using a SDR and conventional freeware software.

In Figure: example of using the ABCS GUI.

1. SDR CONSOLE Output Settings

SDR Console is a free Software Defined Radio Based software used to tune, perform doppler correction, receive the signal and demodulate the satellite signal.

In Figure: SDR Console.

Virtual Audio Cable is a software which creates a virtual audio cable that is used here to connect the output of the SDR Console to the Input of High Speed sound modem. VB-Cable software needs to be installed and the link to download the software can be found in the last page of this document

In Figure: SDR Console Output Setting.

2. High Speed Sound Modem Settings

1. In the input device drop down select “CABLE Output ( VB_Audio Virtual

2. High speed sound modem is used to decode ax.25 Packets and pass them in KISS mode to the AstroBio CubeSatellite GUI

3. The connection from the HS_Sound Modem is done through TCP Server which needs to be enabled as show in the above image

In Figure: Setting Tab in the High speed sound modem.

3. TCP Settings in ABCS GUI

In the TCP settings window configure the client by using the conventional localhost address (127.0.0.1) and the same port number selected in the HS_Soundmodem KISS output configuration.

In Figure: TCP Settings on the ABCS GUI.

Useful Links

SDR Console v3.1

VB-audio cable Downloads

High-Speed Sound Modem