SUNSET2 was launched and recovered successfully a few weeks ago. This was my second attempt at a Propeller powered near-space balloon. You can read about the partially successful first attempt here.

The motivation for SUNSET2 came from a friendly guy named Mark Shepstone, who approached me through the university.  He had read about my previous near space attempt and wanted to help me try again.  Mark generously sponsored the project, allowing SUNSET2 to be a significant improvement over SUNSET1.

This time the payload contained the following (all housed in a styrofoam 6pack coolerbox):

  • My custom parallax propeller powered flight computer (more below)
  • A backup 5W 2m APRS tracker (SkyTracker) powered by 6 Energizer Lithium AAs
  • A GoPro camera with extended battery in its waterproof enclosure
  • An RF beacon for direction finding, usually used for hobby rockets

My second generation near space flight computer performed the following functions:

  • Inside and outside temperature measurements using Maxim DS1822 sensors
  • Transmit GPS and temperature data in APRS packets
  • Take 120×160 colour and BW images once a minute using a uCAM and transmit these to the ground using SSTV

The propeller board was powered by a 1500mAh LiPo battery pack. It transmitted using a 100mW UHF Radiometrix module.

This time the flight was a success! The payload was launched using a 350g balloon from the Cape Town International Airport with the help of the Weather Office. The balloon was tracked and recovered about 200km away in Robertson on a farm. To get there it flew over a fairly large mountain range, making the chase quite difficult! The backup tracker’s signal was picked up by the local APRS network and forwarded to for the duration of the flight. The Propeller board’s signals were picked up by a UHF mag mount omni antenna on the roof of our tracking vehicle. Unfortunately the Propeller’s GPS had trouble maintaining lock throughout the flight. I’m not sure why this was the case. However, beautiful SSTV images were received throughout the flight! I was amazed at how well this worked using only 100mW!