Balloon Payload - alanbjohnston/CubeSatSim GitHub Wiki

This article describes how the CubeSatSim can be used a balloon payload in a High Altitude Ballon (HAB) flight.

While the entire CubeSatSim, including the frame and solar panels, could be flown as a payload, there are some disadvantages such as:

  • The solar panels on the CubeSatSim aren't useful on a short balloon flight (such as a "popper balloon" that goes up, pops and comes back down again. And they aren't efficient enough for a "floater balloon" that flies for long distances in the stratosphere
  • The normal RF power output of the CubeSatSim isn't sufficient for a balloon payload
  • The NiMH batteries in the CubeSatSim don't have the highest power density.

Instead, the modifications described here make for a much better balloon payload.

  1. Minimal components.

Flying the CubeSatSim Lite or just the Main board with minimal components will minimize the weight of the payload.

  1. Bypassing the FM attenuator.

A simple modification can bypass the FM attenuator, which gives 500 mW of power, which is a reasonable amount for a balloon payload.

  1. Non-rechargable batteries.

Using high performance alkaline batteries or lithium batteries will give a longer payload lifetime. The Battery board could still be used, but with, for example, Energizer Max AA batteries, or AA Lithium batteries or another battery pack connected to the JST connector (make sure you double and triple check the polarity, as battery packs use different polarities).

  1. Use the software setting for Balloon Mode.

This is set with the command CubeSatSim/config -H In this mode, the battery low voltage shutdown is disabled. Also, the CW ID in APRS mode is disabled. In the future, this mode will also result in SSTV immediately starting with a camera image and not a stored image.

  1. GPS Module

You can add a serial GPS module to the CubeSatSim or Lite which provides tracking capability. Here's some discussion about how to do this: https://github.com/alanbjohnston/CubeSatSim/discussions/406 However, you shouldn't rely on this as the only tracker on your balloon - you should have another GPS tracker as well.

  1. Script to cycle between modes.

It is relatively easy to write a script that switches between multiple modes. For example, alternating between an SSTV image and several APRS packets that have telemetry data.

  1. VHF FM transceiver module.

The SR105V is a pin-compatible VHF version that could be programmed to use a standard APRS frequency. This allows digipeater and iGates to act as ground station for your payload. You can order it here: https://dwmzone.com/en/walkie-talkie-module/1131-sr105v-vhf-136m-174m-analog-walkie-talkie-transceiver-data-transfer-module.html

With these changes, the CubeSatSim can be a reasonable HAB payload.

If you try flying a CubeSatSim or a Lite on your balloon, let us know how it went by sharing your experiences on the Discussions Board https://github.com/alanbjohnston/CubeSatSim/discussions