The scourge of spam
Like all blogs, projecthorus.org sees its share of spam. For the most part, this is kept in check by comment filters like Akismet - the last couple of months have been a bit of an exception though:
Spammers attack!
Ouch!
Project Horus & Skipping Girl Vinegar
To celebrate the launch of their album 'Keep Calm, Carry the Monkey', Melbourne indie band Skipping Girl Vinegar have teamed up with Project Horus to launch a hobo monkey into space.
In the coming weeks, we'll be launching SGV's hobo monkey 'Baker' into near space, along with selected messages from fans and band members alike.
For more details follow SGV on Facebook or stay tuned to the Project Horus blog. 
Project Horus: 1 Year!
It's been one year today since projecthorus.org went online. 8 flights later, I've certainly learned a lot, met some great people & had a bunch of fun! 
This seems like a fitting time to announce a couple of upcoming launches:
Lonely Planet:
I'm currently working with Melbourne artist Chris Lansell in conjunction with Tony Wheeler of Lonely Planet on a project involving HD video cameras & lots of altitude. At this stage, the project is looking like 2 launches, one carrying several HD video cameras, the other carrying still photography. Lift off is set for mid November, weather permitting!
Jason Hansma:
I've been approached by Dutch artist Jason Hansma to assist him in launching one of his exhibitions to near-space. Jason's based in Perth at the moment, and is working on a concept of launching a sculpture of Hermes (the messenger of the gods) into space, capturing the journey in HD video.
There's even more in the pipeline too.. keep your eye on the blog for updates soon. 
Another successful launch!
Horus 3 was launched today at approx 12:10pm & successfully recovered a few hours later.
The weather was perfect, which made launch so much easier, and (almost) everything went exactly as planned. Thanks to the work of natrium42 & jcoxon in getting the dynamic predictor working in conjunction with the tracker, we were actually able to position ourselves and actually see the payload coming down!
Run for the balloon!
I'll post up a full writeup soon The writeup is here - massive thanks to everybody who helped out with tracking & on IRC!
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- Run for the balloon!
A successful launch!
Project Horus was launched at around 2:30pm local time and successfully recovered at around 4:30pm yesterday, reaching a maximum altitude of 29,606m!
Payload found!
Our launch was planned for 12:30pm, but was delayed by a couple of hours as assembly turned out to take longer than expected. We were further delayed by an odd GPS issue - none of our modules were able to gain lock for about half an hour. We'd also forgotten our scales, so filling the balloon until it had the right amount of free lift turned into a bit of educated guesswork.
We think this looks good...
After much stalling & waiting (unsuccessfully) for GPS lock, we decided to launch without lock, figuring there must be some sort of local source of GPS interference, or bad ephemeris data being broadcast. We tied the balloon to the chute, reflector & payload & let it go...
Ready to launch
Once the balloon was up, we had a few nervous minutes of waiting for it to gain GPS lock, and then another few minutes waiting for altitude to be correlated. Pretty soon the balloon was indicating that it had lock, but its ascent rate was much higher than we had predicted, meaning our landing predictions would be invalid.
natrium42 was following the launch online and kept us updated on the balloon's progress via #highaltitude, as we were too busy driving, making sure we were decoding telemetry & trying to work out where to go to take note of much of what the balloon was doing.
Soon the balloon had picked up speed and was heading east - 2 of our chase cars headed for the freeway to try & catch up, and Adrian VK5ZSN took an alternate route in his more capable 4wd.
Airborne!
A brief while later, we'd reached Murray Bridge, and were still decoding the balloon OK. We started heading north towards Palmer in anticipation of its flight path, but soon realised that the balloon would likely not be getting much higher, as it had just passed 28km. 1600m and a few minutes later, the balloon popped and started heading back down at 200km/h, owing to the lack of atmosphere to slow it down at this altitude. We turned around south of Tepko and headed back towards Murray Bridge, and let the other cars (both of which had stopped for lunch!) know of the balloon's descent.
As the balloon came below 10km, we realised that the parachute must not be working effectively - it was still falling far too fast. We scrambled to place ourselves in ideal spots - one car atop a hill with a yagi antenna following the balloon down to the ground, another racing towards where we thought the balloon would land.
As the balloon landed, I was about 2-3km away - from this distance I could hear the telemetry signal become very weak, though still audible. Our last fix on the balloon was at about 300m altitude. Given its descent rate, it would have hit the ground 5-10 seconds after this, so we would have no trouble finding it. We confirmed with our third car that they were still decoding the landed payload with the yagi from a few km away, and headed to the landing site - where we found Adrian & Co who'd just sought permission for us to retrieve the payload from the farmer whose paddock we had landed in.
The landing site (under the power lines!)
Despite the hard impact, the payload was in good shape (except for the antenna) & was still transmitting data. After a brief introduction to the local cows, we called it a day and headed home to go over the data & photos captured.
Unfortunately for us, we experienced a lot of condensation on the inside of our payload (or maybe ice outside), which resulted in very blurry photos above about 5-10km. This is something which I'll improve on in future, either by flushing the payload with helium to clear any moisture before launch (thanks Rob), or avoiding the use of glass filters to seal the payload up and allowing the camera lenses to poke out of the sealed interior.
Blurry photos
Despite the blurry photos (which we'll improve on next time!), we managed to get some good data, and the telemetry systems worked very well in their first real world test. Several amateur radio operators tuned in for the launch & helped us track the balloon, which was great. Our barometric sensor did a great job of calculating the pressure altitude until it reached it zero-value at around 15km. The payload's external temperature was embedded in the polystyrene foam, which prevented it from registering as low as the temperature no doubt reached - something else to work on next time.
A big thanks to all involved for helping this to be a successful launch - esp to Adrian, Alex, Brad, Guy, Alan, Andrew & Holly for coming out on the day and tracking the balloon with me! An interactive map of the balloon's flight path & our chase car routes is available online, and you can also download it to view in Google Earth.
Chase car tracking
I've written some software to allow our chase cars to post their current positions to the tracker during the flight, as well as the balloon payload.
This means the position of both the balloon & 2 chase cars will be updated in near real time - position updates will be uploaded every 10 seconds. This relies on our chase cars having internet access - we may encounter some areas of no mobile broadband service, though we should have at least GPRS coverage most of the time.
I've included a screenshot of the tracker as I went for a drive to test the chase car tracking software.
Chase car tracking
Quick update
Did not yet get around to doing a tethered test due to the weather here - it's been in excess of 40 degrees C for the last few days.
Visited Adrian and did some testing of the telemetry & found a few bugs - the most notable being that the temperature sensors were failing once the GPS achieved lock. Reason for this was that the interrupt driven software UART to the GPS was throwing off the delays enforced to give the temperature sensors time to take their readings when data was being received. I've since fixed this, and moved to a more accurate timing method for the RTTY telemetry.
The pressure and humdity sensors have arrived and have been connected. The pressure sensor seems to be working correctly, I need to test the humidity sensor against an environment of known humidity to make sure it's also working.
I've started work on a GUI frontend to track all the balloons sensors. I'll upload screenshots of this soon.
Currently awaiting final CASA approval, launch in the next 2 weeks is looking promising, with good wind conditions. Will finish off the tracking page soon & have a few ground based runs to ensure everything is in working order.
Predicted flight path
Current state of affairs
Haven't had much chance to work on the project or update the blog in the last couple of weeks due to the festive season being in full swing - aiming for a launch in a week or two though, I'll set a tentative date soon.
I was given a Sparkfun voucher for Christmas(thanks Holly! ), which will go down a treat. Sparkfun are selling a humidity sensor which I'm ordering for the payload - this simple analogue sensor looks really easy to use, having an almost linear output.
Sparkfun's humidity sensor breakout board
I'm also ordering an MPX4115 pressure sensor from Farnell - a (cheap) absolute pressure sensor with a range from 15kPa to 115kPa. A minimum of 15kPa means that I will only have accurate pressure data upto 45,000 feet, but I don't know of any other sensors which are capable measuring lower pressures in the same price range.
MPX4115 pressure sensor
I purchased a piezoelectric buzzer to be used as a warning tone when the payload descends below 1 or 2km, and to help us find the payload in case it lands in trees or scrub. This little buzzer can run on anywhere from 1-13v, and draws less than 10mA at 5v. Even on a single AA battery, it's very loud!
Piezoelectric buzzer
My balloons have arrived from Kaymont also. I'm planning on doing a tethered test of telemetry & software this weekend, I'll send an email to everybody who's contacted me regarding tracking. Tethered balloons are bound by maximum altitude restrictions, so range will be limited, but hopefully we should be able to get an idea of how well everything is working.
Kaymont balloons
Project update
A big thanks to Michael Kubler of Grey Phoenix Productions for his very generous contribution of components, IC's, PIC's and much more which will no doubt come in handy in the build of the project!
I have also been in touch with several radio amateurs offering both sound advice, and assistance with tracking of the balloon. Thankyou to all who have contacted me and offered input.
I am currently planning to build a small (50-100g) payload comprising of GPS and a radio transmitter to use for radio testing before the real launch - to get an idea of range & performance.
UKHAS Launches
Just followed the launches of Icarus and Xaben by UKHAS members online. The distributed listener modifications that they've made to fldigi worked amazingly well, the payloads were tracked online flawlessly - much to the credit of jcoxton, rjharrison, fnoble, edmoore & others!
Also got my new Atmega328's, and my Arduino is back from the dead. Haven't yet tried flashing it again.
Exams will be over in a week, soon I can spend some more time building up the payload.