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Amateur Operations

Phoenix pictured during deployment from the ISS. High resolution photos were captured by astronauts on board the ISS (credit: Nanoracks (top image) NASA (bottom images))  

Phoenix deployed from the ISS on February 19, 2020 at 9:35 UTC (2:35am MST). Due to an in-orbit anomaly, Phoenix’s health beacon is no longer active, and ASU has ceased operations with the spacecraft. As of August 2020, Phoenix was still operational and capable of two-way communication, but difficult to contact. If you are interested in communicating with Phoenix, please refer to the information provided below; however, note that attempts to contact the spacecraft may be unsuccessful.

If attempting to ping the spacecraft, success may be achieved if packets are sent frequently (~2 seconds apart) when the spacecraft is close to max elevation. If Phoenix receives a ping command, it will reply immediately. As such, if you are trying to validate your ground station, it may be more beneficial to reference the SatNOGS Database for currently active CubeSats, many of which have health beacons of their own that you can practice decoding. For any questions, please contact phoenix.cubesat@gmail.com. 

Following deployment, Phoenix's TLE was confirmed as NORAD ID: 45258, or international designator 1998-067RB, with the help of the SatNOGS database. Observations of Phoenix from its early days in orbit can be found on SatNOGS under ID #45258 - Phoenix (ASU) 

 

Phoenix Transceiver Characteristics 

Hardware Model: GomSpace AX-100 

Operating Frequency: 437.35 MHz

Baud rate: 9600 bps

Beacon Interval: 30 seconds

Bandwidth: 20 kHz

Modulation Type: GMSK (Mod Index: 0.5)

Mode: Narrow-FM

Protocol: AX-25 KISS packets with HDLC encapsulation

Encoding: NRZI G3RUH/K9NG scrambled

Spacecraft Callsign: WJ2XOY 

ASU Ground Station Setup (Hardware-Based)

The hardware below will be used at ASU to track and communicate with Phoenix. If you have a hardware-based ground station setup and would like to listen for Phoenix, please ensure you have a similar setup to what is described below. 

Radio: Icom IC-9100 (FM Data Mode)

Antenna/Yagi: High gain UHF Yagi/Antenna 

Rotator System: Antenna Rotor system to accurately point the antenna to the satellite. The ASU ground station uses the sattrack rotor with P/N: 05194

TNC: Kantronics Packet Communicator 9612 Plus (connected to the radio using the 9600 baud port and set to KISS Mode). The settings file for our TNC can be found here

In addition, GPredict and Hamlib can be used to predict when Phoenix flybys will occur as well as track it while the spacecraft is within range of the Ground Station.

  • GPredict can be downloaded here.
  • You can find hamlib here. 

 

Software-Based Ground Station Setup

You can also listen for Phoenix's packets using an SDR and the following software packages

Software-Based Radios

  • SDR# (software-based radio module ~ compatible with Windows platforms)
  • GQRX (software-based radio module ~ compatible with Linux and Raspberry Pi 3)

Decoding

  • Direwolf (AX.25 packet modem/TNC and APRS encoder/decoder~ compatible with Linux, Mac OSX, and Windows) Direwolf receives input audio from GQRX or SDR# via UDP to display incoming packets.

To use this with SDR#, you will need to download the Audio Stream plugin. More information on the plugin can be found here

For more information on using Direwolf with GQRX, please refer to the GQRX documentation here

 

Sample I/Q and Audio Files  

We have recorded audio files of a simple 'ping' command, which can be sent to Phoenix's AX100 transceiver by amateur operators interested in communicating with the spacecraft (see Simple Command section at the bottom of this page). These sample files along with supporting documentation can be found on our public GitHub repo. 

 

PhxSat Ground Software for Packet Decoding & Command Uplink

Another way to properly decode the messages that Phoenix is transmitting is to use the ground software developed by the Phoenix team. This is only available for Linux Operating Systems, but it allows the user to monitor incoming packets as well as transmit simple "ping" messages to the spacecraft as a way to encourage amateur participation. Please note that you must be a licensed amateur operator in order to transmit a command to Phoenix. You do not need to be licensed to simply receive telemetry, however. The ground software can be downloaded from our GitHub repo. For instructions on installation and usage, please refer to the README file.

Health Beacon Format

While this is no longer functional, following deployment, Phoenix transmitted a distinct health beacon every 30 seconds. This health beacon contained the most vital housekeeping telemetry on the spacecraft to allow mission operators to quickly assess the overall status of the spacecraft. The health beacon was transmitted in ascii to reduce processing on the ground and on the spacecraft. 

 Sample health beacon

hk:33,185,7.35,7.5M,3120347795,0.445,0.178,0.154,7.35,161,297,298,0,0,228,0,0

 

Health beacon interpretation

Position  

Example Value

Interpretation

1

33

Internal Communications Index

2

185

Number of total OBC resets

3

7.35

Current battery voltage

4

7.5M

Amount of disk space currently used on the OBC 

5

3120347795

Current time of the OBC clock. It is formatted as an RTC (Unix)  timestamp, which is the number of seconds since Jan 01, 1970

Keep in mind that this time is 7 hours ahead of the current time in AZ. Therefore, this should be taken into account before assessing clock drift

6

0.445

Current draw from everything getting 3.3V (in mA)

(Note: This is the nominal voltage draw when the GPS, OBC, and AX100 are all getting power) 

7

0.178

Current draw from everything getting 5V (in mA)

8

0.154

Current draw from power switch 7, the switch to the ADCS

9

7.35

Voltage the battery is being charged at via the EPS

10

161

Current the battery is being charged with (in mA) 

11

297

EPS temperature (in K)

12

298

Battery temperature (in K)

13

0

Number of Brownouts

14

0

AX-100 Received Signal Strength Index (RSSI) 

15

228

AX-100 board temperature 

16

0

Number of satellites used in the last GPS solution 

17

0

GPIO State (0 = switch is on the ADCS, 1 = switch is on the FLIR camera)

 

AX.25 Packet Addressing

If transmitting to the spacecraft, your destination address should be set to the spacecraft's callsign: WJ2OXY

If you receive Phoenix's housekeeping telemetry, you should expect to see the following callsigns: KIOO7Y and WJ2OXY

 

Simple Commands for Amateur Participation

In addition to listening for the spacecraft, the team also highly encourages amateur participation. The commands listed below are simple commands that anyone can send to Phoenix and the expected response. Please note that you will need to use our ground software to send the following command to Phoenix or transmit the audio file located on the GitHub repo. In addition, you must be a licensed amateur operator to transmit anything to the spacecraft, as mentioned above. A sample I/Q file and a sample audio file of the ping command can be found on our GitHub repo to assist with operations. 

 

NameCommand Typed in Software DescriptionExpected Response
Ping Command  ping 5‘Pings’ the satellite to ensure it is in range and that you are able to establish two-way communication with the spacecraft. The expected response is essentially a repeat of the packet you sent it.  

"00 01 02 03"

This is preceded by a 4-byte CSP header and followed by a 4 byte CRC

TLE Information

TLE data for all CubeSats deployed on Feb. 19th are now determined and can be found via the resources listed below. You can search for 'Phoenix' in the satellite catalog to obtain its TLE or NORAD ID: 45258. 

 

Sighting History

Any major updates on Phoenix sightings and relevant TLE information will be posted here to keep anyone interested in tracking Phoenix informed. 

2/19/2020: 10:07 UTC ~ First sighting of Phoenix's beacon over Indonesia! An immense thank you to Alfredos-Panagiotis Damkalis for capturing this! 

2/19/2020: 14:14 UTC ~ First sighting of Phoenix from the ASU Ground Station! First CubeSat operation ever performed by the universiity! 

2/19/2020: 19:37 UTC ~ First successful schedule uplink to Phoenix from the ASU Ground Station. 

We would like to extend an additional thank you to Christy (KB6LTY), Scott (K4KDR), Bob (N6RFM), Matjaz, and many others who helped us track Phoenix throughout the day post-deployment so that we could keep track of the spacecraft's health while it was not over ASU.