How to Contact an Orbiting PROVES Satellite

Pleaides - Orpheus is currently in space and operationl as of December 25, 2024!

Pleiades - Orpheus

Parameter	Value
Operational?	Launch Planned Q4 2024
Frequency	437.4 Mhz
Modulation	LoRa & FSK
Spreading Factor	8
Callsign	K06AZM

Bandwagon-2

The Launch of Pleiades - Orpheus

Image Courtesy: SpaceX

Orpheus Radio Config Settings

These are the radio configuration settings defined in the pysquared.py file for the Orpheus satellite. Although it is possible to change these settings in flight, whenever the satellite reboots it will default back to these settings.

        self.radio_cfg = {
            "id": 0xFB,
            "gs": 0xFA,
            "freq": 437.4,
            "sf": 8,
            "bw": 125,
            "cr": 5,
            "pwr": 23,
            "st": 80000,
        }

Tracking Orpheus

You can view a live ground track of the Orpheus Satellite on its TinyGS Page.

Latest TLE

We are currently following this predicted TLE for the satellite. As of December 25th we were still able to get packets on this TLE from both partner stations in Europe and our own operators in the US.

1 99999U 1800100  24356.55210831  .00000000  00000-0  54728-3 0  9999
2 99999  44.9918   0.5192 0006321 333.9104 162.3426 15.19156729    15

This TLE was generated using open-source TLE Tailor Tool.

Pleiades - Orpheus was launched on December 21, 2024 on SpaceX Bandwagon-2! This satellite is jointly built by Bronco Space at Cal Poly Pomona and the Irvington High School Girls in STEM Club. On launch the satellite will beacon appoximately every 40 seconds and listen for 10 seconds after every ping for commands from ground.

Contacting Orpheus

At this time we are working through an on-orbit anomoly that is resulting in an expectedly low transmit power from the satellite (only 20 dBm instead of the planned 30 dBm). As a result, we have only seen sucessful links closed to very well tuned stations with good high gain antennas and low noise floors. This page will be updated with our progress in improving that link budget and openning Orpheus communications up to the world!

At this time, if you would like to make an attempt to hear from or contact Orpheus anyways, we provide the following scripts written in CircuitPython as a means of attempting to receive and transmit an up to 250 byte repeat request digitally to the satellite.

Note that both of these scripts are intended to work with HopeRF derived RFM9x modules that are tuned to the 433Mhz band. An example is provided at this link.

In these scripts, simply replace the mentions of cubesat and radio1 with your own instance of an adafruit_rfm or adafruit_rfm9x object. The scripts are designed to be used with our satellite's flight controller board, which automatically creates a radio1 object with based on the board's internal wiring.

Simple Receiver Script

This script will listen for potential packets and print out any candidates to the terminal. Note that because enable_crc is set to False it will also print out partially received and garbled packets! Because we do not bit pack our data, it is possible to still reconstruct information about the satellite from a partial packet.

import time
from pysquared import cubesat as c

print("=" * 70)
print("Initializing Simple Receiving Script")
print("=" * 70)

c.radio1.node = 0xFA
c.radio1.destination = 0xFB
c.radio1.enable_crc = False
c.radio1.spreading_factor = 8
c.radio1.coding_rate = 5

while True:

    print(f"Time[{time.monotonic()}] Received: {c.radio1.receive(keep_listening=True)} RSSI: {c.radio1.last_rssi}")

    time.sleep(1)

Simple Repeater Script

If you have a second radio module that you can use for transmit this script allows you to send a message (up to around 245 Bytes) that will be repeated by the satellite if it is received within the 10 second listen() window that follows every beacon!

import time
from pysquared import cubesat as c

print("=" * 70)
print("Initializing Simple Repeater Commanding Script")
print("=" * 70)

c.radio1.node = 0xFA
c.radio1.destination = 0xFB
c.radio1.tx_power = 20
c.radio1.spreading_factor = 8
c.radio1.coding_rate = 5
passcode = ""

while True:

    packet = (
            b"\x00\x00\x00\x00"
            + passcode.encode()
            + b"RP"
            + input("Message to Repeat: ")
        )

    c.radio1.send(packet, keep_listening=True)

    time.sleep(1)

    print(f"{c.radio1.receive(keep_listening=True)} RSSI: {c.radio1.last_rssi}")