ADVANCE NOTICE – Horus 48 – Telemetry Test Flight & Test Transmission

On the weekend of the 10-12th of March (exact day TBD), Project Horus will be performing a small (not-so-)high-altitude balloon launch from Mt Barker. The flight will be a short one (~1.5 hrs), with a maximum expected altitude of only 13km. All the payloads have been custom-built to be very lightweight – the total payload mass for this launch is < 300 grams!

The aim of this flight is to evaluate the performance of a new telemetry payload, which uses ‘THOR16‘ modulation. While about half the speed of the current RTTY payload, the THOR modes utilise forward error correction and interleaving. This promises to reduce or remove issues with mobile flutter and multi-path fading that we encounter with RTTY. In short, while we may not be getting telemetry sentences quite as often, we will have a much higher chance of the telemetry that is received being useful to us!

THOR Receiver Tune & Test Day – Sunday 4th March ~10:30AM CDST

To help stations adapt to the new THOR16 signal, this coming Sunday (a week prior to the launch) there will be the opportunity for stations in the Adelaide metropolitan area to set up dl-fldigi as per the linked guide below and have a go receiving a higher-power version of the THOR16 signal. This will be broadcast from Mt Lofty Summit by Mark VK5QI. Mark will be on the VK5RSB 70cm repeater (439.900 -5MHz / 91.5Hz CTCSS) as ‘technical support’, to help assist setting up the software. The signal should be easily receivable from the Adelaide Metro area and some surrounds.

Look for the test signal on 434.640MHz

Horus 48 Launch Campaign – Tentative 10-12th March

For the actual launch the following weekend, the telemetry frequencies for the flight are as follows:

  • RTTY – ‘HORUS’ – 434.650 MHz
  • THOR16 – ‘THORUS’ – 434.640 MHz

Both payloads are running 10mW transmit power, and have essentially identical antennas.

DL-FLDIgi Setup for THOR16

As usual, use dl-fldigi to decode telemetry, but in the case of the THOR16 payload, you will have to manually select the operating mode from the drop-down list as follows:

If you have the capability of running two 70cm receivers, please consider running two instances of dl-fldigi to decode both payloads. This may require either multiple PCs, or multiple sound cards. If you can only run a single receiver, please try and alternate between the different telemetry payloads.

We would very much appreciate reports as to your experiences decoding the different telemetry payloads – please e-mail these through to

Tracking for the launch will be available on the HabHub online tracker. We hope to see you as part of the tracking nets!


73 de Mark VK5QI



Willunga High School Launch – Success!

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On the 7th of December 2017, members of Project Horus participated in the successful launch of the Willunga High School’s 2017 balloon launch. This year Willunga High School was participating in a ‘Balloons Without Borders’ exchange program with the United States ‘Near Space Systems’ – Near-Space Systems would launch Willunga High School’s payload, and the US payload would be launched here in Australia. The US payload contained cameras and various atmospheric sensors.

NearSys BalloonSat Payload

The chase team consisted of Mark Jessop VK5QI, and Matthew Scutter, the developer of, a weather prediction service that Project Horus has made use of many times for launch-day weather predictions. This was Matthew’s first balloon chase, and as is custom, he got thrown straight into the deep end acting as navigator and operator of the chase car software.
Mark describes the launch day as follows:
We launched right ahead of a cold front that was moving in, which threatened to make the flight challenging. During my drive to the launch site I encountered large areas of showers, however the Willunga area stayed clear for quite a while. 
The winds did start to pick up during launch preparations, but were not strong enough to make the launch difficult. We ended up with a total payload mass (combined across the 2x telemetry payloads, 1x Wenet imagery payload, and the BalloonSat) of approximately 1300g.
The flight proceeded pretty much as planned, with an average ascent rate of 5.2m/s. The payload’s ground speed was observed to reach 200kph at some points during the flight. The balloon was cut away at just under the predicted burst altitude of 30km, in an attempt to bring the landing site closer towards the Dukes Highway, a major highway running through the region. The maximum altitude was 29949m. 
The descent rate was faster than expected, around 10m/s on landing. This turned out to be due to one of the payloads tangling with the parachute, causing it to not open completely. This brought the landing location a bit further away from the highway, and made the descent portion of the flight too fast for the our lonesome chase team to get to the landing site in time to watch the landing. 
We arrived about 20 minutes after landing to find the payload in a large, recently cropped field, about 200m from a road. Shortly after we departed, the cold front arrived and the rain started – we had recovered just in time!
All the payloads were recovered in good condition, in spite of the faster-than-expected landing. Constructing the payloads from lightweight expanded polystyrene does have its advantages!
The live Wenet imagery didn’t perform too well, mainly due to lack of receivers. I had a receiver running in my chase car, and Graham VK5EU did a great job of receiving from home.
Thanks also go to VK5HS, VK5APR, and VK5NEX for decoding the RTTY telemetry throughout the flight!
 The flight profile and chase vehicle tracks can be seen here.
The flight statistics are:
Flight Designation:WHS-December 17
Launch Date:07/12/2017 00:11:45 UTC
Landing Date:07/12/2017 02:08:09 UTC (Approx)
Flight Duration:1 Hour 57 Minutes
Launch Site:-35.262946 138.555586
Landing Site:-35.755356 139.736493
Distance Traveled:124.8 km
Maximum Altitude:29,904 m
Thanks to everyone involved in yet another high altitude balloon flight!

SHSSP Horus 41/42 Flights GO for Sunday 22nd

UniSA Flights are GO for Sunday  
Matt and I have just called ‘GO’ for the launches on the weekend. We have enough control variables to play with to be able to make the flights viable with the current predictions. Liftoff will be 10:00am ACDT Sunday from both sites.
Now, onto the current predicted flight paths (with the proviso that things still have a chance of changing a bit between now and then).

McLaren Vale – Horus 41
Ascent Rate: 5m/s
Cutdown at: 32km
Descent Rate: 4m/s
Mt Barker – Horus 42
Ascent Rate: 5m/s
Burst/Cutdown at: 34km
Descent Rate: 4m/s

 How to get involved?
There will be many ways of getting involved in the flight. A live stream of the event will be available (details TBA). You can follow along the university project via their Facebook page as well!
They are also running a competition to name the two balloons. If you’re a primary school or high school student please fill out the form below to submit your idea for a name!  (click here).
Keep visiting our website for ongoing updates for this project!
Details of the payloads and how to track them are available here (click).

Horus 40 Launch imminent – Jan 2nd 2017

Weather conditions are now looking somewhat better for a launch on Monday the 2nd of January. Liftoff is planned for 10.00am ACDT.

Ground wind conditions at Mt Barker should be light, and the current prediction (with some tweaking of launch parameters), has us landing somewhere north-east of Palmer:

Launch Details

The team will be launching from the Mt Barker High School oval. Our NOTAM’d launch time is 10AM ACDT, so we will be on-site from about 8:30-9AM. It is expected that balloon filling will take a bit longer this time, as we really need to get the balloon fill spot-on to achieve the desired flight path. Given this is an AREG test launch, visitors from the Amateur Radio community are welcome!


There will be 5 payload boxes on this flight! (The most in a while)

  • RTTY Telemetry (434.650 MHz 8N1 ASCII 100baud) – The usual RTTY payload as has flown in the past.
  • Flight Control payload (TDMA) – we use this for telecommand to terminate the flight at the right altitude
  • Secondary Test Flight Control Payload (TDMA) – In-air test of new TDMA software updates.
  • Wenet Imagery Payload – 441.200 MHz 115Kbit/s Wideband FSK
  • GoPro HD Hero 3 Video Payload – 25fps 1080p video – to be collected after landing

As usual, you’ll be able to select the flight from a drop-down list in dl-fldigi to decode the RTTY.

Tracking will be available via habhublogo

Wenet SSDV imagery will be available via

Wenet Payload

For those club members involved in the Wenet payload data collection. you *should* be able to decode it using the software stack from last flight, however some Raspberry Pi firmware updates have slightly adjusted what ‘115200 baud’ actually means (115387 -> 115177 baud). Receivers running the old software are going to see a fairly large symbol rate error, and may experience a performance hit because of that. While the old software should work, the best preparation would be to upgrade your software.

As an upgrade, this flight will be sending ‘Full HD’ 1080p images, which should make nice desktop backgrounds! Note that this flight will be sending maybe 2x the number of images as the previous flight, due to some threading improvements made to the software.

As always, the Wenet ground-station software is available on Github at: with an install guide for Ubuntu Linux here. A RTLSDR and a 70cm preamplifier are required for reception.

Launch Site Map

For those who want to see the balloon filled and lift off, here is the venue:



Next Balloon Flight in Planning Stages

The Project Horus team through the Amateur Radio Experimenter’s Group is planning another balloon flight!

Well I’ve got NOTAM’s booked in for the 2nd, 4th, and 6th (Monday, Wednesday and Friday) 10AM, with the plan being to fly on Monday 2nd January. If the predictions are poor for the Monday (which is possible, given what’s coming towards SA weather wise over the next couple of days), then we may have to move to one of the other days, depending on personnel availability.

The flight is intended to have the following onboard:
  • Wenet SSDV payload (new box which I still need to build, new hardware), flying updated software. This will now have live GPS data overlaid on the image, as well as an AREG logo overlay. The images are now also full 1080p, so we’re effectively downlinking desktop backgrounds
  • RTTY Telemetry (the usual, 434.650 MHz)
  • Possibly a GoPro HD video camera We’ll evaluate that one closer to the date, and once I actually have a box made up for it.
Those running Wenet SSDV ground stations will need to update their software before this launch.

High Altitude Balloon Launch WEDNESDAY 27th July with Willunga High School


Andy VK5AKH and Mark VK5QI preping the balloon

Willunga High School undertook a high altitude (well, not so high this time…) balloon launch Wednesday the 27th July, with some tracking support provided by AREG’s Project Horus flight team.

Willunga Balloon Prediction July 2016

WHS Balloon Flightpath Prediction

This flight was organised mostly (gas + balloon + payload + CASA) by a science teacher from the high school, with assistance from myself (telemetry + recovery). The launch being mid-week certainly doesn’t make it easy from our side, so at the moment the tracking crew consists of myself, Gary, and the Adelaide division of IBM Ozlabs (Joel Stanley and Andrew Jeffery).

The flight carryed a GoPro plus the usual tracking & cutdown payloads, beneath a 300g balloon. We expected a burst altitude of around 20km, with a predicted landing zone to the east of Swan Reach:

This was a fairly long distance flight for the predicted altitude, but the predicted flight path holds the promise of some pretty good video of the Adelaide area (assuming the ‘partly cloudy’ prediction happens). The VK5QI chase crew was on the road to Swan Reach roughly 30-45 min prior to the launch time, to get in position to both cutdown (if required) and recover.


During the Chase and recovery

Update: The Flight was a Success!

The flight has been a success and the payload was recovered (albeit a little further away than planned, about 10-15km south of Waikerie). Here was the actual track route from the chase:

Flight Path

Flight Path

The AREG crew helped with filling the balloon as well at the School. Here are their ground crew efforts

The following gives you an idea of some of the frames collected by the camera for the school!

And the following is the recovery action

Thanks to Gary VK5FGRY, Mark VK5QI and Andy VK5AKH for the photos!

PicoHorus Launch and Recovery!

PicoHorus “N+2” was launched at 11AM CDT on Saturday the 2nd of Jan 2016. The payload consisted of a light telemetry beacon, weighing in at 45 grams including batteries. A small latex balloon was used, deliberately under-filled in an attempt to achieve a ‘float’ condition at approximately 30km altitude.

The payload was launched near Mt Barker in the Adelaide Hills, from a fairly windy hill:

The wind, combined with the very small amount of balloon neck lift resulted in the balloon not rising at all for a few minutes! Eventually the balloon rose above the higher ground winds, and continued on upwards at the desired ascent rate of 1m/s.

The telemetry beacon transmitted the ‘standard’ RTTY telemetry as well as an experimental binary FSK mode developed by David Rowe. The binary telemetry was transmitted between the RTTY telemetry frames, and proved to be far more reliable than the RTTY telemetry, especially in low SNR conditions(more to come on this!). Unfortunately the demodulator for the binary telemetry is not quite in a ‘user friendly’ state yet, and so it was only used by a small number of listeners, with the rest using the dl-fldigi software. Special thanks to Joe VK5EI and Ivan VK5HS for tracking the RTTY payload through the majority of the flight!

PicoHorus N+2 Flight Profile

PicoHorus N+2 Flight Profile

The balloon proceeded to head east to the Victorian border while slowly ascending to a maximum altitude of 28376m. After floating for approximately 20 minutes, the balloon burst, sending the payload plummeting to the ground at 15m/s. The balloon was tracked down to 3.3km altitude by Ivan, from his home QTH near Renmark. The final position placed the balloon about 25km north-west of Pinaroo, SA, approximately 200km east of the launch site.

PicoHorus N+2 Landing Area

PicoHorus N+2 Landing Area


This payload wasn’t originally intended to be recovered, but given the landing location looked reasonable for a recovery, Andy VK5AKH and Mark VK5QI decided a Sunday drive was in order to see if the payload was still operational.

Leaving Adelaide at around 8:30am, they arrived at the expected landing site around 11:30am to find the payload still transmitting strongly, and reporting a position just 50m away from a road. A short walk into a field had the payload in hand!

Thanks again to everyone that helped out decoding telemetry, without your input we would have not been able to recover the payload.

Our next balloon launch is scheduled for late January – stay tuned!

73s, Mark VK5QI

Project Horus Pico Launch – 2nd January

PicoHorus PayloadsThis Saturday (2nd Jan 2016) at around 11AM, Mark VK5QI and David Rowe VK5DGR will be launching a “Pico” (sub-50g) balloon payload, with the aim of testing a new Binary FSK telemetry mode. This is intended to be the next evolution of the Project Horus 70cm RTTY down-link and should result in more reliable telemetry, but without the slow update-rate penalty of data modes like Olivia or JT65

The binary telemetry modem is still under development, and the de-modulator currently only exists as a collection of Octave and Python scripts. However, the payload will still be transmitting the ‘classic’ RTTY telemetry on 434.650MHz, along with binary telemetry on the same frequency. A guide to tracking using dl-fldigi is available here.

The launch is intended to have a very slow ascent rate (~1m/s), with the intent of causing the balloon to float at around 15-20km altitude. However, the balloon is of fairly old stock and may burst early. If a float does occur, the flight path should track towards Victoria.

As always, listeners are much appreciated, especially as we won’t be chasing this flight. The flight will be trackable on the day at:

73s, Mark VK5QI