Project Horus – Telemetry Test Flight #2 (Horus 51) Flight Report

Today’s telemetry test flight (now designated as Horus 51) was performed with (mostly) good results! This launch was an experiment to investigate solutions to the ‘Horus Binary’ payload PLL-loss-of-lock issue that has been observed on previous launches. Three payloads were launched, with variations on insulation and transmit power, all using reprogrammed Vaisala RS41 radiosonde PCBs. As a result, there was a lot of telemetry to receive on this flight!

Getting ready to launch the payloads

The launch was a fairly relaxed affair, with only a small launch crew on-site. Launch occurred right on time at 11AM. It was quickly discovered that a bit too much helium was used (dodgy gas flow-rate meter!), and so the ascent rate was higher than expected resulting in the small balloon used bursting at 16.2km altitude.

Horus 51 Flight Path

As the pre-launch flight path prediction had the landing area somewhere south-west of Loxton, none of the launch crew attempted to chase this launch. Instead, Ivan (VK5HS) from the Riverland Radio Club lead a small team (Ivan, David and Peter) out from Renmark to recover the payload. As it turns out, the higher ascent rate and lower burst altitude resulted in the landing location being further away from Loxton than expected, but the Riverland boys were able to track payloads down to the ground and easily recover them not long after landing.

David (left) and Peter (right) with the recovered payloads.

Many thanks to Ivan & Co for making the effort to get out and chase, it is much appreciated!

Horus 51 - Flight Statistics

MetricResult
Flight Designation:Horus 51 - Telemetry Test Flight #2
Launch Date:2018-11-25 00:30 UTC
Landing Date:2018-11-25 01:40 UTC
Flight Duration:1 Hour 10 Minutes
Launch Site:-35.07568, 138.85701
Landing Site:-34.68642,139.92380
Distance Traveled:106 km
Maximum Altitude:16,201 m

Telemetry Statistics

Thanks to all who participated in the launch by receiving telemetry from one (or more!) of the three payloads. Statistics on how much telemetry was contributed by each receiver callsign is below:

Horus 51 - HORUSBINARY (434.640 MHz) Receiver Statistics

CallsignReceived PacketsPercentage of Flight ReceivedFirst-Received Altitude (m)Last-Received Altitude (m)
VK5FAAP403.7%49152951
VK5HS29226.9%1283660
VK5KX-3100892.7%632125
VK5NEX33530.8%148634601
VK5QI-951647.5%340142
VK5ST-489382.2%23741301
VK5WTF20.2%39593969
YOUR_CALL_HERE47844.0%2339296

Horus 51 - HORUSBINARY2 (434.650 MHz) Receiver Statistics

CallsignReceived PacketsPercentage of Flight ReceivedFirst-Received Altitude (m)Last-Received Altitude (m)
VK5APR11717.7%9053849
VK5FJGM26740.3%339410661
VK5KJP54682.5%20541313
VK5KX-264196.8%763103
VK5LJG46670.4%12754751
VK5LJG-940861.6%3641809
VK5NEX39659.8%290714293
VK5QI-964497.3%378103
VK5ST-253681.0%2248893
YOUR_CALL_HERE31447.4%298114293
vk5mad38558.2%146414293

Horus 51 - 4FSKTEST (434.660 MHz) Receiver Statistics

CallsignReceived PacketsPercentage of Flight ReceivedFirst-Received Altitude (m)Last-Received Altitude (m)
VK5APR78475.0%40513538
VK5DSP11611.1%926512591
VK5KX-2121.1%1515115449
VK5QI-961658.9%340144
VK5ST-188184.3%24041246
VK5WTF80877.3%601395

Please make sure you follow the configuration instructions when using the Horus Binary decoder, to avoid the ‘YOUR_CALL_HERE’ entries seen in the above tables!

Payload Testing Results

Previous Horus launches have seen the repurposed Vaisala RS41 payloads lose PLL-lock mid-flight, with the transmit frequency drifting up the 70cm band as temperature decreases. Testing on the ground indicated this may be due to the Radio IC (a Silicon Laboratories Si4032 FSK transmitter) failing with the low temperatures experienced during flight. The fact that the the RS41 sondes do not usually fail during their intended application pointed at the lower transmit power (25mW vs 50mW) used on Horus flights being a possible factor.

On previous flights the following results were seen:

  • Horus 49 (Anstey 2.0) – RS41 Foam Only, 25mW – No issues Encountered.
  • Telemetry Test Flight #1 – RS41 Foam Only, 25mw – Failed on Ascent at 9km altitude, recovered on descent at 1km altitude.
  • Horus 50 – Stock RS41, 25mW – Failed on descent for ~6 minutes between 13km and 9km altitude.

With 2 failures and one success, it was decided that more data needed to be gathered.

Foam-Only (Left), ‘Stock’ RS41 (Middle), Custom Enclosure (Right)

On this launch, two payloads were operated at 50mW transmit power, one with a ‘stock’ enclosure (‘HORUSBINARY’) and one with only the inner foam insulation (‘HORUSBINARY2’). Using only the inner foam insulation provides a significant weight reduction, cutting the payload weight almost in half (~120g to ~60g).

A third payload (‘4FSKTEST’), using a custom-built foam enclosure was also tested, transmitting at 25mW. This had a similar overall weight (66g) to the foam-only RS41 enclosure, and re-flew the RS41 board that failed on Horus 50.

A bug in the firmware, discovered after the Horus 50 flight, was also fixed for this launch. This fix allowed gathering of measurements from a temperature sensor on the silicon die of the radio transmitter IC – unfortunately the temperature measurements captured on previous launches are invalidated as a result of this bug.

Horus 51 Payload Temperatures

Sadly, the foam-only payload (‘HORUSBINARY2’) was observed to fail at 14.3km altitude during ascent, and recover at 4.8km on descent, failing with a radio IC temperature of 0 ˚C.

Failure of the HORUSBINARY2 payload, as observed by Joe VK5EI

Both the stock RS41 and custom enclosure payload remained operational throughout the flight. The overall higher temperatures reported by the Stock RS41 payload may be a result of a bias in the temperature sensor, or may be a result of the better insulation – Further investigation will be performed once the payloads make their way back to Adelaide.

Curiously, the two other payloads reported radio IC temperatures lower than the failure point of the foam-only payload (0˚C), indicating that perhaps it is not the radio IC at fault, but another component on the PCB. Further investigation will be performed on RS41 PCBs using selective cooling of components, prior to the next Horus launch sometime in January 2019.

However, based on the results from this flight, it appears that the safest option for the moment is the Stock RS41 enclosure, transmitting at 50mW. As always, Horus flights use  redundant telemetry transmitters, so that a failure of a single transmitter does not compromise our ability to track and recover!

Project Horus – Telemetry Test Flight #2 – Sunday 25th November 11AM CDST

UPDATE: Predictions look good, so this flight will be going ahead as planned. The launch team will not be chasing this flight – others are welcome to chase/recover the payloads if they wish.

Current planned flight parameters (for prediction purposes) are a 4m/s ascent rate, 20km burst altitude, and a ~7m/s descent rate.

 

On Sunday, the 25th of November, Project Horus will be performing a small balloon launch from Mt Barker High School Oval, at approximately 11AM CDST. Live flight tracking will be available on the HabHub online tracker as usual. A guide on how to decode the new Horus binary telemetry mode is available here.

This launch is another test flight of the new ‘Horus Binary’ telemetry payload, which uses a new modulation mode developed by David Rowe VK5DGR and Mark Jessop VK5QI with 6dB better performance than the usual RTTY telemetry. This telemetry mode has been flown on a few recent Project Horus flights, with mixed success – The modem has performed flawlessly, the payloads themselves not so much! These flights have flown reprogrammed Vaisala RS41 radiosondes, which while working perfectly on Bureau of Meteorology launches, have proven troublesome on Horus launches!

Drifty Horus Binary Payload – Hopefully not on this this flight!

The last telemetry test flight suffered a loss of PLL lock on ascent, believed to be due to temperature issues, causing the payload to drift right up the 70cm band. On Horus 50, a similar fault occurred on descent, though the payload recovered within a few minutes. Further investigations confirmed a temperature issue, likely due to the lower transmit powers used on Horus flights (25mW) compared with the stock transmit power of 50mW.

This flight aims to test a few different variations on the payload flown on Horus 50, to determine if transmitting at a higher power keeps the payload alive. A few different modifications to the payload insulation will also be tested.

Currently we plan to fly 3 telemetry payloads (all on USB, +/- temperature drift):

  • 434.640 MHz – Callsign ‘HORUSBINARY’ – Unmodified RS41, 50mW TX power.
  • 434.650 MHz – Callsign ‘HORUSBINARY2’ – RS41 without outer plastic shell, 50mW TX power. Prioritise reception of this payload.
  • 434.660 MHz – Callsign ‘4FSKTEST’ – RS41 PCB in custom enclosure, 25mW TX power.

The Horus Binary uploader script will automatically determine the payload callsign as long as you are running a recent version. Please make sure you have updated to the latest version (2018-11-15) of the Horus Binary uploader before this flight, otherwise the HORUSBINARY2 payload will not be recognised, and data for the other payloads may be corrupted. Those who were set up for Horus 50 can simply download the latest payload ID list, and place it in their horusbinary directory.

Launch will be from the usual Mt Barker High School Oval site, and launch teams will be on-site around 10:15AM, for a 11AM launch. All are welcome!

AREG 20th Anniversary – Horus 50 Flight Report

Introduction

The Amateur Radio Experimenters Group was formed in July 1998 with the aim of promoting experimentation and self learning using Amateur Radio. 20 years on, the group is a vibrant and active body that has brought together people from many walks of life, all with the common interest of experimenting and learning about radio and electronics.

One of the founding project ideas conceived by Adrian VK5ZBR, Ben VK5BB and Rod VK5UDX that drove the creation of AREG was project “Skyhook“. The aim, back then, was to fly an amateur radio payload under a weather balloon. For various reasons that goal was never achieved. However, through Project Horus (which joined AREG several years ago under the then stewardship of Terry VK5VZI), that original dream became a reality.

The view from Horus 50 – River Murray in the foreground with Adelaide in the top left of shot

This flight marks Project Horus’s own milestone, having now launched 50 “heavy – 30km plus” balloons over 8 years. In that time it has become one of the most active amateur high altitude balloon projects in Australia.

To commemorate both the 50th flight and the 20th anniversary, AREG and Project Horus have decided to fly an all Amateur Radio oriented payload, promoting our core experimentation theme. The aim was to maximise involvement of the amateur radio community in the project. Here is the story of that flight.


Horus 50 – Launch Preparations

The launch crew arrived on site at Mt Barker High School by 8.30am ready to prepare the payloads and the balloon. Mark VK5QI who was flight lead was assisted by a number of AREG members including Will VK5AHV, Andrew VK5AKH, Theo VK5IR (first time Horus hunter), Kim VK5FJ, Marcus VK5WTF, Oly VK5XDX, John VK5BJE and Grant VK5GR with a number of other visitors and members who came along to watch as well. Assembly of the balloon train went to plan and, with relatively calm conditions prevailing, the filling of the balloon went smoothly too.

Liftoff

After the obligatory calls to Air Traffic Control, the team was set and the balloon took to the skies on schedule at 10.00am ACDT.

Ground Tracking & Control Stations

In support of the flight, another AREG team had set up camp approximately 50km away at Bear Rock Lookout, up above Palmer on the eastern edge of the Mt Lofty ranges. Manned by Peter VK5KX and Matthew VK5ZM, this ground station provides a vital backup telemetry link, gathering all of the signals from all of the payloads and uplinking them to the internet for the chase teams to use.

This data, when mixed with the rest of the information being received by amateurs across the state, is used by the chase teams to help fill in any packets they miss from the balloon, improving the accuracy of their landing predictions and providing a safeguard for the landing positioning data.

Meanwhile the second ground team, consisting of Grant VK5GR and Oly VK5XDX, went to the top of the ranges above Brukunga to establish VK5ARG net control for this flight’s voice repeater. We weren’t able to collocate these teams as the UHF high power up-link would have overwhelmed the tracking data down-links.

The Chase Teams

Once the balloon took off, the Mt Barker based chase teams packed up the launch site and prepared to head out. Meanwhile Darin VK5IX also started the chase, in his case also from the Bear Rock lookout. There were a few new chase teams this time which was great to see! The teams were:

  • Mark VK5QI: Mark VK5QI, Will VK5AHV, Theo VK5MTM (his first Horus chase)
  • Liam VK5LJG: (Just Liam, his first Horus launch, though not his first balloon chase)
  • Kim VK5FJ: (Just Kim in the car)
  • Marcus VK5WTF: Marcus and family
  • Darin VK5IX: Darin, Glenys, Cam, Greg.

It was great to see more people getting out chasing!

 

Tracking and Telemetry Data Processing

There were many ways to track the flight. The usual balloon telemetry collection site was in full swing at habhub.org where all four payloads were being tracked. Amateur Radio operators and the general public could also track this flight via the Amateur Position Reporting System (APRS) on websites like aprs.fi

APRS Tracking from aprs.fi

habhub.org tracking and telemety hub

The other very important aspect of the flights is the data collected by the distributed listener network of amateur radio enthusiasts spread across the state. This adds a huge level of reliability and redundancy to the system that the project team really appreciates. It also gives everyone an opportunity to contribute to the project, even if only from their own radio shacks.

The interest in this flight was very high and there were many first time listeners as well as many regulars tune in and gather the telemetry off one of the RTTY or 4FSK payloads, as well as through the APRS Internet Gateway network.

In all of these a special mention goes to Andrew VK3BQ who takes the prize for the most distant telemetry decoding station at over 600km away in Melbourne.

Here are the results of how much telemetry each station was able to contribute (Note – This is per-callsign used when uploading, so some stations may have duplicate entries):

100 Baud RTTY Beacon 434.650

CallsignPackets Received% of Flight Received
VK5NG85076.2%
VK5ZRL84575.7%
VK5AKK78270.1%
VK5EU77769.6%
VK5KX-264157.4%
VK5APR42738.3%
VK5DJ40836.6%
VK5ALX32829.4%
VK5KX-0232128.8%
VK5ST17415.6%
VK5KX-816214.5%
VK5KX-0813912.5%
VK5DMC13311.9%
vk5st736.5%
VK5NEX373.3%
VK5KIK322.9%
VK5QI-9292.6%
VK3BQ191.7%

4FSK Binary Beacon 434.640

CallsignPackets Received% of Flight Received
VK5QI-9169388.2%
VK5KJP166686.8%
VK5WTF123964.6%
VK5NEX119362.2%
VK5LJG-9117661.3%
VK5ST-9105655.0%
VK5LJG88946.3%
VK5FJ-987745.7%
VK5TRM84243.9%
VK5DSP62732.7%
VK5FAAP32416.9%
VK5ST623.2%

A huge thank you to everyone who collected the telemetry!

This telemetry stream also allows us to analyse the path the balloon took and to confirm the flight’s vital statistics:

Not all plain sailing for the telemetry

The flight was not without it’s gremlins either. The 4FSK binary telemetry payload, which was a recovered Vaisala RS41 Radiosonde that has been re-programmed for use on 70cm, lost PLL lock at 13km on descent, and regained it at 9km altitude (about 6 minutes later). The air temperature at 13km was <-60 degrees C according to the morning BOM radiosonde launch, and -40 degrees C at 9km. The team suspects that the payload froze for a period due to it running lower power than it would for a normal sonde launch, thus not generating enough internal heat to keep from freezing. It is hoped to test this out sometime in the towards the end of the month with a small test launch carrying the same payload but running 3dB more TX power along side another RS41 PCB in a custom foam box (similar to our RTTY payload boxes).

The LoRa tele-command payload also had a fault where it lost GPS lock for the second half of the flight just after burst, likely due to it getting knocked around due to the huge dynamic shock that ripples through the payloads when the balloon bursts. This time, the GPS unit took 20 minutes to regain lock, probably because it was falling so fast (~20-60m/s). The team will be investigating some better AA battery holders, and possibly putting a big capacitor across the power input to hold up the GPS through that very dynamic part of the flight.

It goes to show, every flight is an experiment and that the team learns something new every flight!

Payloads – Slow Scan TV

The main attractions of this flight, of course, was the flying voice repeater and the first flight of the Slow Scan TV transmitter.

The live pictures broadcast over Slow Scan TV were a spectacular success, with amateurs across VK5 and VK3 able to receive them using all manner of tools and systems. The SSTV signal, running 250mW used what is known as Scottie 2 format (commonly used on HF).  For the first time these images were accessible to almost everyone without any special software (which the previous high definition Wenet SSDV picture system does require). This helped generated an unprecedented interest in the flight.

We had clubs and individuals from the Riverland, South Coast, across Adelaide, and in one case from as far away as Melbourne all receiving the SSTV transmitter.

Rick Kearsley (from the South Coast ARC) received SSTV images from Horus 50 from Normanville SA with  by VK5LEX/P and VK5VCR/P.

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In the Riverland, Peter VK5PE and Ivan VK5HS joined in the fun.

AREG also received copies of the pictures received by Steve VK5SFA and Liam VK5LJG and know of several others in Adelaide who also successfully received the images live from the balloon (including our primary ground station at VK5KX/P, who received one only 500ft off the ground).

Last SSTV Image before landing captured by VK5KX

The best effort award however must go to Alan, VK3DXE who from the eastern side of Melbourne was able to receive the SSTV transmitter at apogee using his EME station. Not a bad effort for a 250mW FM transmission on 145.1MHz at over 630km range.

VK3DXE Receiving Horus 50 SSTV from Melbourne over 600km away

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This was the array Alan was using.

Photo thanks to VK3DXE

From the balloon’s perspective we also kept a copy of the images on the SD card. This is what they looked like prior to broadcast.

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Payloads – Voice Repeater

The other amateur radio related payload flown was a cross band voice repeater. This machine had a receiver on 438.900MHz (with a 123Hz CTCSS tone) and a transmitter on 147.500MHz running approximately 1 Watt. This was a return to the original voice repeater flown back on Horus 9 and 23 after the problems with narrow band FM on the more recent repeater flights.

During the flight, it became clear that this old machine still had some problems. Unfortunately the faults didn’t reveal themselves until after lift off. The repeater was de-sensitising its own receiver (a suspected 3rd harmonic problem), and with the rather windy flight aloft, there was also a lot of swinging around of the antennas (TV Ribbon J-Pole antennas) which made contact very difficult to achieve through the balloon. None the less, 32 contacts were logged through the repeater by stations from as far as Millicent in the SE, Renmark in the NE and Whyalla / Port Pirie in the Iron Triangle to the NW.

Contact Map (created using tools.adventureradio.de/analyzer/)

The following is the full log of the contacts made through the balloon with net control.

VK5ARG Log

CallQSO_Begin_DateQSO_Begin_TimeFreqModeQTH
VK5QI2018-11-032338Z147.5FMGlenelg
VK5GR2018-11-032338Z147.5FM
VK5PET2018-11-032339Z147.5FMStrathalbyn
VK5XB2018-11-032341Z147.5FM
VK5IR2018-11-032341Z147.5FMMansfield Park
VK5BJE2018-11-032341Z147.5FMMaurice
VK5WTF2018-11-032344Z147.5FMMunno Para
VK5APR2018-11-032345Z147.5FMFlinders Park
VK5KX2018-11-032345Z147.5FMSalisbury Park
VK5ZM/P2018-11-032346Z147.5FM
VK5ZAR2018-11-032347Z147.5FMBroadview
VK5BB2018-11-032351Z147.5FMRedwood Park
VK5IX2018-11-032352Z147.5FMFreeling
VK5YX2018-11-032356Z147.5FMHallett Cove
VK5PE2018-11-040013Z147.5FMRenmark
VK5DJ2018-11-040014Z147.5FMMillicent
VK5HS2018-11-040015Z147.5FMRenmark
VK5ST2018-11-040019Z147.5FMAngaston
VK5ZRK2018-11-040020Z147.5FMRidgehaven
VK5DMC2018-11-040023Z147.5FMPort Pirie
VK5ALX2018-11-040024Z147.5FMWhyalla Playford
VK5XB2018-11-040029Z147.5FM
VK5SFA2018-11-040053Z147.5FMWoodforde
VK5AKK2018-11-040100Z147.5FMCrafers
VK5WU2018-11-040108Z147.5FMHope Valley
VK5TEC2018-11-040115Z147.5FM
VK5HS2018-11-040118Z147.5FMRenmark
VK5CV/MOB2018-11-040120Z147.5FM
VK5EU2018-11-040122Z147.5FMHilton
VK5KBJ2018-11-040126Z147.5FMAldinga Beach
VK5ZM/P2018-11-040128Z147.5FM
VK5JP2018-11-040142Z147.5FMNorth Haven

Payload Recovery

As sure as the laws of gravity go, what goes up must come down! The balloon climbed to over 35km before bursting and returning to earth. The following are the vital statistics of this flight:

MetricResult
Flight Designation:Horus 50 - AREG 20th Birthday
Launch Date:2018-10-03 23:14 UTC
Landing Date:2018-10-04 01:59 UTC
Flight Duration:2 Hours 45 Minutes
Launch Site:-35.07568, 138.85701
Landing Site:-35.184284, 139.755216
Distance Traveled:82.6 km
Maximum Altitude:35,861 m

The chase teams themselves were in an excellent position to recover the payloads and indeed watched them land from about 1km away. After contacting the land owner (to seek permission to enter and collect them), all of the payloads were successfully recovered, ready to fly another day.

Recovery Team – L-R VK5IR, VK5LJG, Greg, Cam, VK5WTF, VK5IX, VK5AHV, VK5QI

Conclusion

At the end of the day the team was very happy with the results. What was even better were the number of people who participated in the event, either on site or from home with tracking, SSTV, FM voice, or just tuning in on social media and following along via the Internet. It truly represents the aims of AREG in promoting experimentation in Amateur Radio to see all of the people who joined in. To each and everyone of you, thank you for your participating!

To the teams that built and flew the balloon, a special thank you to you as well. May there be many more!

73 de Grant VK5GR

Horus 50 Frequency & Tracking Data

If you wish to take part in either communicating with / via Horus 50 or are simply curious as to what is going on the following summary should help. Liftoff is planned for 10AM ACDT (2330z) Sunday morning.

Where is the Balloon?

You can track the balloon via the HabHub Website. Follow this link

What Frequencies can I listen on / talk through?

  • 147.500MHz Downlink / 438.900MHz Uplink (with 123Hz CTCSS) Repeater
  • 145.100MHz Slow Scan TV Downlink (using Scottie 2 format)
  • 145.175MHz APRS Tracking Beacon
  • 434.650MHz 100baud RTTY Telemetry
  • 434.640MHz 4FSK Binary Telemetry (uses the latest FreeDV software to decode)

When using the FM voice repeater be aware that it will be under controlled net conditions and that the chase teams have priority at all times to use the repeater to coordinate recovery. Net control will be VK5ARG – call in to VK5ARG and listen to instructions please so that everyone can get a turn.

In particular, remember to turn your CTCSS tone on your 70cm transmitter and set it to 123Hz. Forgetting to do so will jam the repeater for every other user.

Where can I get up to date information?

If you have a twitter account, watch Hashtag #horus50 . Updates will also be posted on the AREG’s Facebook page as events unfold.

[custom-twitter-feeds hashtag=”#horus50″]

Further details about the telemetry etc can be found on the main flight information bulletin available from (here).

If i want to see the launch where can I go?

We are launching from the southern oval at Mt Barker High School. The team should be on site from 9am.

Good luck and enjoy this celebration of the 50th flight of Project Horus in the 20th year of the Amateur Radio Experimenter’s Group.

UPDATE: Horus 50 High Altitude Balloon Flight this SUNDAY!

Preparations continue for the Horus 50 high altitude balloon flight celebrating the 20th Anniversary of AREG. This radio experimenters flight is planned for launch this Sunday, the 4th of November at 10am CDST (2330Z). The latest flight path prediction is shown below. Full details of the flight can be found (here)

UPDATE: 3rd November 2018 – Predictions still looking good!

Tracking will be available via habhub.org

As a quick reference, the flight will have the following transmitters:

  • 147.500MHz Downlink / 438.900MHz Uplink (with 123Hz CTCSS) Repeater
  • 145.100MHz Slow Scan TV Downlink
  • 145.175MHz APRS Tracking Beacon
  • 434.650MHz 100baud RTTY Telemetry
  • 434.640MHz 4FSK Binary Telemetry (uses the latest FreeDV software to decode)

Stay tuned for more details and refer to the main news story (herefor information on how you can participate in this event!

AREG’s 20th Anniversary Event – Horus 50 Balloon Launch – 4th November 2018

2018 marks 20 years since the Amateur Radio Experimenters Group was formed. To celebrate this milestone, the club is planning to fly a special Amateur Radio focused high altitude balloon in what will be the 50th Project Horus Mission.

The Project Horus team itself is also celebrating 8 years in the air! Project Horus was founded by Terry Baume and continues to perform regular high-altitude balloon launches from locations around South Australia under the auspices of the Amateur Radio Experimenters Group.

When will this be happening? Currently it is planned to fly on Sunday the 4th of November (weather permitting). Liftoff is planned for 10AM ACDT. We are going for altitude so coverage will hopefully extend as far as Melbourne at the peak of the flight.

The goal is to engage with amateur radio in as many ways as possible. We want you to talk through the balloon, see the world from the balloon’s perspective and know where the balloon is during the flight! How can you do all this you might ask? The Project Horus team have specifically tailored this flight to include:

  • a 2m (down) / 70cm (up) Cross-band FM repeater. Amateurs within the repeater footprint will be able to make live QSOs with the club station VK5ARG and each other via the FM repeater using relatively modest stations.
  • a 2m SSTV beacon transmitting images from the balloon live during the flight. You will be able to see the world from the balloon’s perspective using a 2m receiver and simple software (you can even use an app on your phone).
  • Track the balloon via a 2m APRS beacon during the flight!

The launch site will be the usual Mt Barker High School Oval. Launch crews should be on-site around 8:30-9AM. If you haven’t attended one of our launches before, this is a great opportunity to come along and see what’s involved first-hand!

As usual, there’s always the chance the weather for the planned launch date may not be suitable, so a backup launch date of Sunday the 18th of November has been tentatively penciled in (the 11th being the AHARS buy & sell weekend).

Cross-band FM Repeater

Likely suspects operating the cross-band repeater on Horus 23

The cross-band repeater will be using the following frequencies:

  • Uplink: 438.900 MHz, with a 123 Hz CTCSS tone required for activation.
  • Downlink: 147.500 MHz  (~1.4W output power).

To transmit to the balloon at the maximum range of 700km (once the balloon reaches >30km) you will need approximately 10-30W and an 10dBi gain antenna and a clear takeoff towards the balloon. Those stations closer to the launch site will be able to get away with much less.

PLEASE MAKE SURE YOU can hear the repeater before transmitting
and remember to make sure you SET YOUR CTCSS TO 123Hz
or you will not access the repeater.

As with previous flights, the repeater will be run as a controlled net. Listen for VK5ARG acting as net control and please follow their instructions so that as many people as possible can share the repeater.

FM-SSTV Imagery Payload

Instead of the usual Wenet imagery payload this launch will have a new SSTV transmitter operating on 145.100 MHz FM. It will run approximately 250mW transmit power. The transmitter will have 30 second gaps between image transmissions to avoid overheating the transmitter.

Scottie 2 SSTV Imagery Example

The payload will be transmitting images using the Scottie 2 SSTV mode throughout the flight, and can be decoded using any SSTV software capable of decoding this mode (pretty much all of them!). This is a mode that typically is used on HF but is equally adapted to VHF FM work. (Note it is not the same as the PD120 transmissions from ISS).

Examples of suitable software you can use to decode the SSTV pictures include:

Any FM receiver (including handhelds) should be capable of receiving this payload, though as with the cross-band repeater, a Yagi antenna may be necessary for reliable reception at the edges of the transmitter footprint.

If you do receive images, please post them to Social Media and on Twitter include the #horus50 hashtag so everyone can see them!

Telemetry Payloads

As always, we’ll be flying the usual assortment of telemetry payloads, including:

  • Our usual 100 baud 7N2 RTTY telemetry on 434.650 MHz USB. This can be decoded using dl-fldigi, with a reception guide available hereNOTE: There is a known issue with dl-fldigi where it does not upload any received telemetry until about 10 minutes after the software is started. Any telemetry received in this time period will be queued and uploaded after the startup period has completed (i.e. no telemetry will be lost).
  • 4FSK Telemetry decoder

    The new 4FSK Binary telemetry will be transmitting on 434.640 MHz USB. This uses a separate decoder, with setup instructions for this available here. (Previous listeners note that there have been updates to the software – please re-download the latest version!). We would love reports of how the 4FSK signal compares to standard RTTY!

  • If weight permits, there will be an APRS beacon operating on 145.175 MHz with the callsign VK5ARG-12. This will be received automatically by the APRS network.
Tracking of the flight will be available on the HabHub Tracker, available at this link. (Note that other balloon launches will also be visible on this page, including the Bureau of Meteorology launches from Adelaide Airport).
Follow the #horus50 hashtag on Twitter for updates from the launch and chase teams on the launch day.
Stay tuned for updates closer to the launch date…
73
Mark VK5QI

Horus Telemetry Test Flight 29th July 2018 – Flight Report

With all the successful flights that Project Horus has had recently, I guess it’s about time we had one that didn’t quite go to plan…

Windy conditions at the launch site made filling difficult

First up – the weather. If this was a full-size Project Horus launch, we would have likely cancelled and re-scheduled the flight. However, since this was just a small test flight with a disposable payload, we decided to have a go.

Thankfully we didn’t experience the forecast showers, however 30-40kph winds at the launch site made filling an exciting experience, with the balloon blown all over the place. Mark VK5QI, Will VK5AHV, Chris VK5FR and Matt VK5HZ were the launch crew for the morning. Graham VK5GH also made an appearance. Just as we were starting to tie off the balloon a wind gust came up and tore the balloon off the fillter… goodbye balloon! (Memories of Horus 8, though this time without the garage to stop the balloon flying away).

Bye bye balloon… (Photo courtesy Matt VK5HZ)

There was just enough gas left in the cylinder to fill a small ‘backup’ balloon (a 100g Hwoyee) and get enough lift to get the payload in the air.

The achieved ascent rate after launch was ~3m/s, a bit lower than the planned 5m/s, however with the switch to a smaller balloon, this actually resulted in a fairly similar flight path to what was originally planned.

The first part of the flight went pretty normally. Many receiving stations came online to decode the new 4FSK Horus Binary mode, including a few new callsigns. Will VK5AHV and Mark VK5QI headed off towards Bear Rock to track the payload as long as possible, while Marcus VK5WTF was already stationed up on Accomodation Hill to do the same. Ivan VK5HS and Peter VK5PE were already out in the expected landing area (South of Loxton), recovering the morning’s Bureau of Meteorology radiosonde launch.

Faulty payload!

At just about 9km altitude… something went wrong in the payload. The signal became very wide, and then immediately started drifting up the band. The current theory is that the payload flew through a cloud on ascent, and a combination of condensation within the payload and extreme cold caused some problem with the radio IC. UPDATE: Testing has confirmed that the issue was related to insufficient insulation around the radio IC. Better sealing around the payload edges solves the issue, and hopefully this won’t occur on future flights.

The transmitted signal continued to drift up through the 70cm band, topping out at about 436.4 MHz before descending back down again. At some point (estimated to be about 21km altitude) the balloon burst, sending the payload quickly back towards the ground.

As we watched the signal drifting back down the band, we wondered – what will happen when it gets back to the original frequency – 434.640 MHz? Sure enough, as the frequency drifted closer towards 434.640 MHz, the drift rate sped up, and it almost ‘snapped’ back into place – and the 4FSK started up again! (Later analysis of the telemetry showed that the GPS & micro-controller continued operating while the radio went walkabout.)

Quickly we rushed to get the decoder up and running again, to find the payload was at ~1km altitude and dropping fast. From Bear Rock we were able to decode the payload down to ~300m (at a distance of 140km, not bad!). Peter VK5PE’s home station in Renmark was able to track it down a bit further, to ~220m.

Ivan and Pete turned around (they were halfway back to Renmark) and were able to recover the payload not far from the last reported position.

Peter VK5PE with the payload in hand!

Even with the issues this flight, we still met the primary goal of getting stations decoding the new Horus Binary telemetry mode. Stations seen to upload telemetry included:

VK5APR, VK5EI, VK5FJGM, VK5FLJG, VK5KJP, VK5KX, VK5NEX, VK5PE, VK5QI, VK5ST, VK5TRM, VK5WTF, and ‘AUSMEZ’

Thanks to all for your participation! We will be evaluating the received data and working out better ways of weatherproofing the modified RS41 payloads to avoid the issues encountered on this flight. Expect to see the Horus Binary telemetry on future flights!

Horus Telemetry Test Launch – Sunday 29th July 11AM CST

UPDATE: Unfortunately the payload failed at approximately 9km altitude. It recovered on descent just prior to landing, and we were able to get a landing location. Ivan VK5HS and Peter VK5PE were able to recover the payload from the middle of a large field south of Loxton.

Thanks to all that decoded the initial part of the flight. If you could please e-mail your log files through as mentioned below that would be appreciated.

This coming Sunday, the 29th of July, Project Horus will be performing a small balloon launch from Mt Barker High School Oval, at approximately 11AM CST. Live flight tracking will be available on the HabHub online tracker as usual.

This launch is another test flight of the new ‘Horus Binary’ telemetry payload, which uses a new modulation mode developed by David Rowe VK5DGR and Mark Jessop VK5QI with 6dB better performance than the usual RTTY telemetry. The first flight of this new payload was on the Horus 49 (Anstey 2.0) flight, where it performed well!

A modified Vaisala RS41, which transmits the new Horus Binary telemetry

The aim of this flight is to provide another opportunity for listeners to attempt decoding of this mode. Like the RTTY telemetry, the Horus Binary telemetry can be received using a 70cm Single-Sideband receiver. Telemetry will be on 434.640 MHz USB (+/- temperature drift). This will be the only payload on this flight, and we are not intending on recovering the payload (though others are welcome to go after it!).

Decoding of the the new mode is not supported in dl-fldigi, and hence new software must be installed – a guide on how to install and run the required Horus Binary decoder software is available here.  (A note to those listeners that decoded the binary payload on Horus 49: a few new features have been added to the Habitat uploader utility – please update to the latest version!)

To help debug some issues that were encountered on the last flight, it would be appreciated if all listeners e-mailed the ‘telemetry.log’ and ‘horusb_debug.log’ log files (created by the horusbinary uploader) through to Mark VK5QI (vk5qi@rfhead.net) at the conclusion of the flight.