This is a blog about my HAB (High Altitude Ballooning) projects.

To contact me: dave@daveakerman.com

Please note: This blog attracts quite a bit of spam now pretty much all of which is dealt with automatically. There’s a very small chance that if you make a comment it will be treated as spam. I no longer read the spam reports so if you think this has happened just drop me a line on the above email address.

58 Responses to About

  1. Peter Askey says:

    At Prince William School in Oundle,Northamptonshire we are looking to launch a similar programme to what you have done with Buzz and Cloud. Can we please have some advise on some issues that we have encountered. The main problem is liability for the baloons decent and where it lands. Please may you tell us how you overcame this issue. Thank You on behalf the PWS Astronomy Club

    • dave says:

      Insurance is a tricky issue – people have tried but failed to get any insurance company interested. The actual risk is very low. If I remember correctly the met office launch 3 balloons daily from each of 6 locations in the UK, and they’ve had very few payouts (typically £200 for broken glass in a greenhouse). Average is something like 20 pence per flight. If you do manage to find insurance please let me know, but I’d be very surprised if you can.

      Instead you should follow sensible precautions, principally using the flight predictor at http://habhub.org/predict/ to ensure you’re not going to land in a town or city or near an airport. UKHAS (UK High Altitude Society) has a set of guidelines at http://ukhas.org.uk/guides:guidelines and those are well worth following. Also ask on the #highaltitude IRC group for any particular advice. I’m on there most days, nickname “daveake”.

      • Peter Askey says:

        Thank you very much that is a real help to us!!
        Another question that we have been undecided about is the payload to baloon size ratio. What size payload and baloon have you used for your projects
        Many Thanks

      • Mike, DL2MF says:

        IMHO insurance is mandatory, think about how a touchdown on a highway could cause much more than some broken glass.

        I’m member of the german amateur-radio club DARC e.V. and we have a group insurance for one year since June 2012, before that it was also a little tricky but possible. Many insurances are offering policies like for glider pilots etc., but for a single start only the cost were ~ 200,- EUR here in germany.

        But we would never had launched HAAROB 2012 if we didn’t had an insurance and also informed DFS.

        More details:

        73 de Mike, DL2MF

        • A Numerate-Reader says:

          I can’t help wondering whether you also take out insurance against tripping over as you cross the road. Just think of the potential multi-car pile-up you might cause.

          Seriously, though, people often buy insurance as a consequence of fear or panic without being aware of the statistics or probabilities involved. These are the only rational way to assess risks. It is a shame that so few people learn sufficient mathematics, specifically the areas mentioned, to be able to make sensible risk assessments and decisions.

          For a lighthearted understanding about how important this is read any of the popular books by John Allen Paulos. You will smile and learn.

          Meanwhile, try a little scientific thought experiment: when was the last time you, or anyone you know, was hit by a descending hot air balloon?

          Hmmm. Thought not.

          • Edd says:

            Well, people prefer “losing” a small fixed amount of insurance premium to avoid the very small chance of losing a lot of money. That’s typical for humans, makes sense to me and that’s why insurance exists.

            and yes, people usually have insurance against causing a mass accident when walking. In German its called “Privathaftpflicht” and almost everyone has it.

  2. dave says:

    Paradoxically, I’ve used larger balloons when I’ve had smaller payloads….

    For photographic flights my payloads have been around 700-1000g, and for those I’ve used 1000g balloons. My other flights have been altitude record attempts, and for those I’ve used a 1600g balloon to carry a much smaller payload (100-150g).

    Next time I’m hoping to fly a payload that weighs around 55g.

    The best size depends on your payload weight and what you’re trying to achieve. Most “normal” payloads are around the 1kg mark and a 1000g balloon can take those to around 30km.

  3. Dave, the blog about the foil balloons was really interesting. Do you happen to have any tables for foil balloon sizes, free lift, and payload weight…or any rough figures I could use?
    Many Thanks
    Chris Hillcox

    • dave says:

      Chris, I just aimed for 1m/s ascent rate, measured by letting go of the balloon indoors and letting it fly to upstairs!

      There are some figures on the UKHAS wiki.


  4. Ron Chen says:

    Hi Dave

    I’m at the Movement Ecology Lab at the Hebrew University in Jerusalem, Israel. We’re looking to develop a GPS receiver + transmitter + several other features for tracking birds. Top weight should not exceed 11-12 grams. From browsing through your blog it seems you were able to build very small dataloggers. I’d be happy if you could contact me at the attached e-mail address to discuss potential development procedure of such a device.


    Ron Chen

  5. enrico says:

    Hi Dave,

    I’m a science photographer based in London. Could you please contact me about a HAB photo project that I’d like to discuss with you.

    Thanks, enrico

  6. Dave
    I’m helping set up a network of RaspberryJam events around the UK and beyond.
    Would you be willing to present at one of our events?

  7. Kate says:


    My school is running a similar project which I’m involved in, and I would love to know what type of knots you used that worked so well!

    Thank you


    • dave says:

      I just make them up as I go along 🙂

      Actually, I just do a few half-hitches and then put a small piece of duct tape over to stop it unwinding. Always tape up all knots.

  8. Hi Dave,
    I’m planning an interactive, educational HAB science experiment event to be held in Manchester next year and although I have started to purchase equipment (NTX2, GPS, GSM etc), I am now wondering if you and your associates would be interested in doing the HAB part, since it is probably best to leave that to the professionals? Rather than try to take too much on and re-invent the wheel. Would this be something you may be interested in doing via a video-link to Manchester?


  9. Dave Johnson says:

    Hi Dave,

    I’m organising the speakers for the AMSAT-UK meeting in Guildford in September this year. Any chance you or someone from UKHAS could give us a talk on your recent exploits. (SRD# / dl-fl-digi might go down well).



    • dave says:

      September’s probably not good for me – I have a foreign trip plus a couple of talks booked already. Might be worth asking on the UKHAS mailing list especially as a couple of the others there know a lot more about SDR and dl-fldigi than I do.


  10. Matt says:

    Hello. After seeing your project i am interested in giving this ago myself. Currently doing research. Please can you help advice on what GPS device you use with your Arduino.

    Thanks for any help you can provide on this.

    Kind Regards,


  11. Catherine Stephenson says:

    Good morning,
    I have just come across your project and I am both amazed and intreged. I there a possibility that I could attend a launch and or a retreval?
    I will of coure make my own way to any launch area or start of a retrival. I of course appreciate that you must recieve many requests of this kind and that it may not be possible.
    I would be greatful if you would contact me via me label.
    Catherine Stephenson

  12. Catherine Stephenson says:

    Good morning,
    I have just come across your project and I am both amazed and intreged. I there a possibility that I could attend a launch and or a retreval?
    I will of coure make my own way to any launch area or start of a retrival. I of course appreciate that you must recieve many requests of this kind and that it may not be possible.
    I would be greatful if you would contact me via my Email.
    Catherine Stephenson

  13. Nuno says:

    Hi Dave,
    I’m building my own HAB right now inspired in the work you’ve done so far.
    I am wondering if you ever thought about avoiding the ballon burst so that it can also be recovered and used again.


  14. Nuno says:

    Probably doesn’t mean it is not possible.
    The cost of the balloon itself deserves a second look at this issue. Maybe some kind of system that recovers the ballon to a box while the payload is descending.
    Anyway, just an idea.

    • dave says:

      Possible – probably.

      Pointless – definitely.

      Latex is delicate. Recovering it would be very difficult. Equipment to recover it in flight would cost extra helium what you save in latex. Also, latex degrades with UV anyway. I would not spend any time trying to save something that is cheap to replace and very probably would need to be replaced even if recovered.

      • Nuno says:

        I guess you are right. Ok, let me then focus in building my HAB – my very first – and let’s see form there. Thanks.

        • dave says:

          Yes, the KISS principal applies to HAB, and especially applies to a first flight. I’ve done around 17 flights now and I still wouldn’t attempt to recover the latex even if I thought it was a worthwhile thing to do.

          • Nuno says:

            one more topic, just for discussion: have you ever thought about at certain altitude start releasing some of the helium inside the ballon, but still maitain lift. This way, hopefully, we can get higher.

  15. Fredrik Krafft says:

    Hello Dave,

    Please get back to me at my email. I believe that we can have some exchange.


  16. Thorsten says:

    Hello Dave,

    last Year we have made 4 HAB Starts.

    This year i will use the PI for SSDV Pictures, ist will be nice if you get back per email that we can have some exchange about that.

    Best Regards

  17. Hi there Dave, I am putting together an article on what UK HABists have planned for 2013 and wonder where your project may go this year; particularly with the Raspberry Pi. I hope to hear from you soon – Chris – Balloonnews.wordpress.com

    • dave says:

      Next Pi flight will hopefully be on 26th or 27th January. It’ll have a few new things but, sorry, I’m keeping those as a surprise for now!

  18. Phil A says:

    Hi there Dave, our Primary school is considering whether this sort of a project might be good as a fundraiser and as PR event for our school build project (we are in West Berks). Bit like the teddy launches that Cambridge and Southampton have done that made national press. I have read quite a bit about HAB but have no practical experience and was hoping you could provide some guidance on a first launch to get some fun upper atmosphere photos and (hopefully) recover some matchbox experiments from the airframe. I’ve contacted Reading Uni Meteorology department who are interested but apparently have not sent a radiosonde so high or done photos/recovery but could help with trajectory calcs to help with an event to get the kids switched on to science. Happy to come and see you to discuss and understand what kit I need to get to do this on a tight budget like Project Icarus MIT students http://space.1337arts.com/
    Thanks, Phil

  19. Mike, DL2MF says:

    Hi Dave,

    really a nice project and fantastic photos from upper space. I did link to your page from my personal blogsite (http://blog.dl2mf.de) and our club-homepage (http://www.darc-celle.de).

    Currently we are in the plannings of our HAAROB’14 project for next year with 2 or 3 launches, our last successfull balloon launches were at 23.06. and 07.07.2012 with 3 balloons and successfully recovered payloads near to the river Elbe 😉

    Could you please grant me to use your photos to describe some of your project details on our balloon pages. If you like, please visit us, have a look into our picture gallery and leave a greeting in our guestbook.

    73 de Mike, DL2MF

  20. Nick says:

    Hi Dave,

    Love reading your HAB exploits & have done a few experiments myself, very basic stuff.

    I’ve always been a fan of the Raspberry Pi & was wondering if the source code & schematics for your working Pi launches will be made available for future adaptation by others – I would love to do something similar 🙂


  21. hi dave, congratulations to your and babbage`s mission from salzburg, austria, hometown of Felix Baumgartner, before he left for switzerland. our reports about your project you find down here:



    you even have made it on the front-page of our national network ORF.at

    continue rocking! best!
    jerry :-))))

  22. jones says:

    Hi! I’m planning about sending my RPi into near space and I was hoping to get some advice!

    1) Is it pointless to put the parachute inside the load and make it open with a Servo? Or the descend time has almost no influence on the landing site?
    2) I live very close to the sea, so there’s a chance that the load will fall into the salt water, should I waterproof it, or changing the launch site is a better option?
    3) After I’ve made the calculation for the amount of helium to put inside the balloon, how do I practically measure the quantity I’m putting in, while inflating the balloon? Every helium tank I saw did not have any indicator whatsoever.
    4) Should I wait for the summer to launch the balloon, hoping for hi-pressure, in order to go higher?

    Thank you, you’re work is really inspiring!

  23. Brendan says:

    Hi Dave

    I was hoping that you might be able to help me with an issue I am having. Over the last 12months I have taught myself how to build and program a HAB with much help from wesites like yours. Unfortunatley I have no programming or electronics training, but I have managed to get everything working except for the dl-fldigi, I keep on getting an error response when it reads my sentence and I can’t work it out. This is a link to my code https://github.com/meniis/sat1/blob/15fa705bd3049745363f6a92986e602a4c233231/.SAT1%20HAB%20Code
    I would really appreciate if you could help shed some light on this for me. If you are willing to help I can email you a screen shot of the dl-fldigi to show you what I am talking about.
    Lastly, sorry about my code, I know it probably looks like a mess to someone who knows what they are doing.


  24. simon cartlidge says:

    im sending a camera up to take images of the earths curvature for a college project we are in the early stages of planning and only have a small budget approx £250 can you reccomend a balloon and parachute and what size we are using a polystyrene box with a small camera and gps /hand warmers weighing approx 1000g
    any help would be gratefully recieved
    many thanks
    simon cartlidge

  25. Dan says:

    Firstly, I’ve very much enjoyed reading your site and I wonder if you could offer some advice please. I am involved with a group of Year 12 children (15-16 year olds) who are preparing a HAB project. They are wanting to incorporate two cameras – the cameras have not yet been chosen. My question is, as well as sending back the telemetry and sensor data, is there a way to send back images from at least one of the cameras? Possibly using a camera module for the Arduino? Any feedback would be appreciated.

    On the hardware they have built their own shield comprising uBlox 7 GPS, NTX2 transmitter, OpenLog for data logging, a BMP085 pressure/temperature sensor all interfaced with an Arduino Leonardo. Transmission antenna is a down hanging homemade coax pigtail with radiating elements and the receiving antenna is a home made Yagi. Everything is powered using 3 x AAA Lithium batteries providing 4.5V and 3000mAh (output 5v using high efficiency boost). The software has been adapted and simplified from the Habduino shield.

  26. Rok Capuder says:

    Hi Dave,

    I recently purchased the habduino for a school project, and I have a question – if you could help me. Do you think I could put the 151,3 Mhz Radiometrix transmitter for the APRS transmitter on the back side of the board? I have my own receiver and decoder for the APRS packets.

    Other functions work great, and the dl-fldigi ballon mode is just superb! Thank you for a great product!

  27. Hey Dave

    Is there any possible way to buy your gps and NTX2 prototype or soc circuit. If possible please let me know as soon as possible.

    Thank You

  28. Todd Calhoun says:

    Just heard and then later read an interesting article this morning that was broadcast by NPR about using low-cost cell phones as satellites. Made me think of the work you are doing and the many similarities. Take a gander when you get a chance.

    cell phone satellites

  29. vidur gupta says:

    Hi, sir.

    I am attempting a similar project in the USA. I need a little help with the raspberry pi. I am trying my best to have a Skype meeting with you, as I am building the weather balloon with my school. We finished the balloon, but I always wanted the Raspberry Pi in space. You can contact me at twitter on @vidurgupta. I currently follow you on twitter so a private message would be great.


    Vidur Gupta

  30. Mark says:

    What is the estimated cost of this unit after production begins?

  31. charlie ryan says:

    Hi Dave,

    we are trying to launch a high altitude balloon with payload of many gopros. We’re looking for someone who could help us with this – are you interested? if so, it would be great if you could contact me directly by email.

  32. Darryl Hedges says:

    IMHO, the key piece of the puzzle for both regular HAB flights and pico ballooning is the tracking element. How did you learn how to put together a tracking transmitter? I can’t seem to find anyone here in my area (Chicago, IL) who knows anything about micro-electronics. Any suggestions? Any chance of being able to buy your transmitters from you? Thanks!
    Darryl Hedges

    • dave says:

      For the USA you should first consider flying an APRS transmitter, as you have a network of listeners already set up. Check with your local ham radio club as you would need a license (easy to get though).

  33. Dave says:

    Just stumbled on your site after reading about it on the raspberrypi.org site. At first thought: “huh, wth? What does my name here?” But than I saw their missed a k…haha. But you do have some nice things here.
    Keep it up.

    Greetings from an almost identical named guy,

    Dave Akkerman

  34. Gary Whitton says:

    Hi Dave

    I am a secondary school teacher working with a STEM club to make a payload to take photographs from a high altitude balloon. We are having difficulty sourcing a parachute – any suggestions?

    many thanks


  35. Nick Langley says:

    we spoke a couple of weeks ago about a possible project.
    Could you contact me ASAP as this seems to be moving forward.

  36. Renaud says:

    Hi Dave,
    I’m trying to contact you on your email to exchange on the coming European Telemetry Conference, but it seems that the emails don’t get through!?

    I’d appreciate your writing back to the email below.



  37. Don says:

    Hi Dave
    Thank you for sharing all the knowledge!
    I already have the original PITS and now I am finally ready to move forward.
    I have the Pi Camera Module, and I would prefer that it takes video, rather than stills.
    Is that possible?
    Many thanks

  38. Sterling Peet says:

    Hi Dave,

    I am advising a group of students at Georgia Tech that are pursuing a high altitude balloon mission. While I have read lot about doing balloon missions, I have not actually attempted nor participated in one myself. I have a few questions that I have not been able to find answers for, and I am hoping you could help. Most of these concerns are related to mission planning, which is what we are currently doing.

    Also, i noticed that your email bounced when I tried to send it direct.

  39. Nolan Perry says:


    My Name is Nolan Perry, I am 15 and a Student at Bridges Prep, in the United States, I am working with a few other students from my school to make a “Pi in the Sky” project of our own, and i was wondering if you could provide a materials list of what we need, divided up into what component it goes to. I’ve tried to figure it out, but i couldnt figure out what posts are components of the Balloon Project. Would you be willing to make one for us to use?

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