A comparison of HAB / Weather balloon flight computers

HAB / Weather balloon Flight computer comparison

Off the shelf flight computers have now been available for several year. But there is always space for a new offering. The UK company ‘SENT TO SPACE’ has recently launched a new offering in the form of their ‘Black Box’ flight computer. To mark it’s launch we thought it was high time that we compared a range of different flight computers to see what they had to offer and to rate them on their value for money.

First off, here is a rundown of the different computers on offer:-





Cost £





Temperature, Humidity,

Pressure, IR,

Visible light, Lux

90.7g including sensors




High Altitude Science Eagle




36g excluding sensors




Hexpert Zlog 7




52g including sensors




Sent to Space Black Box











***** high   * low



Zlog 7

Zlog 7

High Altitude Science Eagle

High Altitude Science Eagle

Sent to Space Black Box

Sent to Space Black Box

Here are some general comments on the trackers:-

From personal experience, the Skyprobe has proved to be a useful and effective flight computer with many sensors. For those users in the UK, the US units can be a little annoying. The battery connection also takes little wear and tear and I have already had to have mine re-soldered on.

The Hexpert is an effective tracker for the price paid. It also has the option to attach a cut down board which works well. It is the only flight computer with an alpha numeric display, and while this may seem pointless, is actually reassuring to see it logging data.

Like the Hexpert and Skyprobe, the Eagle comes without a dust proof case. Given that it only offers temperature and pressure, it is also very expensive. It’s light weight is comparable to the Zlog 7.

Not much is known about the Black Box. Like the other flight computers, the BB has a micro SD memory card reader and a range of meteorological sensors. Unlike the other flight computers though, it comes with it’s own dust proof box. Though we don’t know the weight of the BB, we can assume that this would make it heavier than the other flight computers. This is added to by the whopping 6 AA batteries used to help power a circuit board heater.

Interestingly the BB has a magnetometer which we assume is to measure the Earth’s magnetism and an accelerometer, to measure the acceleration experienced by the payload. This shows a departure from traditional meteorology sensors and the ability to explore other forces. Focusing on the traditional meteorological sensors, I am not sure where the humidity sensor is located and would like clarification that it gives accurate readings despite being located in the box, as humidity is notoriously hard to record.

Customer service





Start up company RockZip looks for investors to help it manufacture super pressure balloons



A US startup needs your help to get off the ground. They make high-altitude balloons — balloons that go really high — higher than airplanes. In fact, some go into space. But starting a company is expensive, so they want people to invest in them.

Austyn Crites is the co-founder and president of Rockzip Highballoons. The company makes inexpensive high-altitude balloons. Crites believes there is a major market for these types of balloons.

“Over 800 weather balloons are launched every day around the world,” says Crites.

Right now, high balloons are used for things like monitoring weather, providing Internet access and testing rocket equipment. But Crites says there is so much more potential — especially for his balloons.

“Most people who think of weather balloons or balloons that go into high altitudes, typically think of latex type. But as they go up higher they stretch until they eventually pop — in about an hour,” explains Crites, “Our balloons are different. They are made from plastic skin. So as the balloon goes higher you can then reach a float time. Our balloons are floating for about 5 hours.”

Crites says schools can use his balloons for science demonstrations. Farmers can use them to monitor crop conditions. And he even believes NASA could use balloons to inexpensively transport cargo into space.

Right now they are testing their smaller balloons, which in the past have floated into other states. The Rockzip team attaches GPS trackers and cameras to their balloons. Their last balloon floated into an Ohio bean field.

Rockzip are proposing to manufacture two types of balloons, the PRO and the BETA. The Pro is designed to float at 30,000ft while the BETA is designed to float at 65,000ft. The balloons also have different float duration. The Pro is designed to float for 5 hours and the the BETA is designed to float for 12 hours. There are also obvious differences in design shapes.



Rockzip has also given us an insight into the valve design for the balloon. 


People can go online to back the business:



Balloon News compares the Garmin VIRB and Go Pro Hero 3+ Black cameras



In recent years action cameras have come and gone but few have posed a real challenge to the dominance of the Go Pro Hero series. The Go Pro’s market share dominance may, however, be under threat by the new offering from Garmin in the form of it’s VIRB camera.

According to Garmin’s web site, the VIRB boasts:-


1080p HD video recording with 16 megapixel CMOS image processor

Chroma display: color, high-resolution; easier control of setup, playback and adjustments

Long-lasting rechargeable lithium-ion battery, record up to 3 hours at 1080p

Rugged, durable, waterproof (IPX7¹) with an aerodynamic design

One of the most attractive features of the VIRB is the built in Garmin GPS unit which records the camera location in an offline mode.

Source http://sites.garmin.com/virb/?lang=en&country=US

With all of these impressive features, we thought we would run off the top of the range VIRB Elite against the Go Pro Hero 3+ Black to see which performed better in the HAB environment. We did two test flights across the UK and the results were surprising to say the least.


Flight 1

Date: 25/03/2014  Launch 5:45am  Landing: 7:58am

Launch site: https://www.google.co.uk/maps/@52.9849266,-3.9664361,511m/data=!3m1!1e3?hl=en

Tanygrisiau, Vale of Ffestiniog, Blaenau Ffestiniog, Gwynedd LL41 3TW

Landing Site: https://www.google.co.uk/maps/@53.0130305,-4.2371323,1706m/data=!3m1!1e3?hl=en

Balloon: 800g Cosmoprene

Payload Weight:1000g

Equipment: Go Pro Hero 3+ Black, Garmin VIRB, SPOT Messenger, SPOT Gen 3, SKYPROBE flight computer

Picture 1 – Just before launch

Top Go Pro Hero 3+ Black    Bottom Garmin VIRB Elite

Top Go Pro Hero 3+ Black Bottom Garmin VIRB Elite


Picture 2 Just after launch

Top Go Pro Hero 3+ Black    Bottom Garmin VIRB Elite

Top Go Pro Hero 3+ Black Bottom Garmin VIRB Elite

Picture 3

Top Go Pro Hero 3+ Black    Bottom Garmin VIRB Elite

Top Go Pro Hero 3+ Black Bottom Garmin VIRB Elite

Picture 4 Just before balloon burst

Top Go Pro Hero 3+ Black    Bottom Garmin VIRB Elite

Top Go Pro Hero 3+ Black Bottom Garmin VIRB Elite

In the first flight the Go Pro Hero 3+Black (with bacpac), running at 1080 video at 24 fps, ran for 2hours 56 min, about 20 minutes longer than the VIRB (1080p 30fps) which ran for 2 hours and 36 minutes. The quality of the video was mixed with the Hero giving a better image prior to launch. The VIRB give a more pleasing image just after launch, and both cameras giving a similarly pleasing image mid way through the ascent and at burst.

snowdon flight path

Flight track from GPS in Garmin VIRB Camera


Flight 2

Date: 27/05/2014  Launch 12:38 am

Launch site: https://www.google.co.uk/maps/place/The+Betsey+Wynne/@51.938886,-0.830506,17z/data=!3m1!4b1!4m2!3m1!1s0x4876fecc32bdb6d1:0xe9a679fe6a54774d

 Landing Site:
Land adjacent to Stratford Rd, Shennington, Ox
Flight duration 121 minutes
Balloon: 1200g PAWAN

Payload Weight:1000g

Equipment: Go Pro Hero 3+ Black, Garmin VIRB, SPOT Messenger, SPOT Gen 3,Cattrack, art work by Rachel Mathewson

Camera performance: Go Pro Hero 3+Black plus bacpac :- 126 minutes approx

Garmin VIRB:- in excess of 121 minutes but last file became corrupt. No GPS recorded.

The results are shown in this short film put together by Whitestone Media


The footage from the Go Pro Hero 3+ was sharper and more pleasing than the Garmin VIRB though the difference in the quality was not great.


All in all I found that the Garmin VIRB held it’s own against the Go Pro Hero3+ Black, with instances where is offered a more pleasing image. The Garmin  VIRB also offered the function of GPS logging, as well as many of the functions offered by the Go Pro Hero 3+ Black. The Black does however offer the higher resolution modes, though these are hard to make use of in the context of high altitude ballooning. Both cameras were very simple to use, though the one push button of the VIRB had the edge over the Hero 3+ Black.

Can SPOT trackers work upside down?

One of the often quoted drawbacks to the use of SPOT trackers for high altitude ballooning is that the antenna needs to point up. Such is the perceived need for SPOT trackers to point up to the sky that some people go to the lengths of making a gimbal that keeps the tracker upright. My experience of HAB flight using SPOT trackers suggests that it you may not loose contact with your SPOT tracker if it does go upside down.

My first experience is that the SPOT tracker rarely spends much time pointing straight up. With the pitch and yaw of the payload, the tracker is most often not pointing straight up. Further, I have seen improved coverage from orientating the tracker to the horizon, and in line with the main HAB tether line. In a flight I carried out on 8th October 2013, I had two SPOT trackers for tracking. The SPOT Messenger (green) was in a polystyrene payload box and a SPOT Gen 3 (blue) was attached to the tether line and arranged parallel to the tether line. Here is the resultant track.

SPOT Gen 3 and SPOT Messenger

SPOT Gen 3 (blue) and SPOT Messenger (green)

Both trackers worked and the SPOT Gen 3 operated marginally better.

In a collaborative flight I did in July, 2013 I used two SPOT Messenger trackers, one orientated upwards towards the sky and the other intentionally orientated down. The flight was designed to ascend the payload upright and descend the payload upside down. Throughout  the flight contact was maintained with both trackers in broadly equal proportion. The payload happened to land on it’s side and both trackers carried on reporting their location until they were turned off.


HAB flight from Aviemore

HAB flight from Aviemore

But what if the tracker lands upside down? In this circumstance it is common belief that the SPOT tracker will not report it’s location. But this is not always the case. In several of my HAB flights, even though the SPOT tracker has been face down, the tracker has still been able to return location messages.

Flight from Aberystwyth

Flight from Aberystwyth

In this instance the payload (bottom right) was upside down in an upland forest in wales and the SPOT still reported it’s location.


In a HAB flight over Snowdonia, the SPOT Gen 3 (centre left) positioned on the main tether landed face down but was still able to return it’s location.

The SPOT tracker is not always able to return it’s location messages when face down and I have come across instances when it has not been able to return the location of it’s final resting place. And while this is not a study, just anecdotal evidence, it does show that the spot can still work even though the tracker is upside down.

First there was Pi. Now there is Choco Pie for HAB High Altitude Balloons







South Korean activists launch ‘Choco Pie’ balloons

Choco Pies – banned as a capitalist symbol by North Korea after being traded at inflated prices – carried in balloons across border.

South Korean activists have launched balloons across the border withNorth Korea carrying thousands of Choco Pies – a favoured chocolate snack that has become the target of a reported crackdown.

About 200 anti-Pyongyang activists released 50 helium balloons carrying 350kg (770lbs) of snacks, including 10,000 Choco Pies, from a park in the border city of Paju, organisers of the event said.

The humble Choco Pie – a confection of chocolate-coated cake and marshmallow – has become an oft-referenced footnote in the volatile history of inter-Korean ties.

Offered as perks to North Koreans working in South Korean factories in the Kaesong joint industrial zone, Choco Pies spawned their own black market and were traded on at sharply inflated prices.


According to media reports in Seoul, the emergence of the South Korean snack as an unofficial currency became too much for the authorities in Pyongyang, who in May ordered the factory owners to stop handing them out.

“Embarrassed by the growing popularity of Choco Pie, North Korea banned it as a symbol of capitalism,” said Choo Sun-Hee, one of the organisers of Wednesday’s balloon launch.

“We will continue to send Choco Pie by balloons because it is still one of the most popular foodstuffs, especially among hungry North Koreans,” Choo told AFP.

South Korean activists regularly launch balloons, usually carrying anti-Pyongyang leaflets, across the border.

Pyongyang has repeatedly pressed Seoul to stop the activists and threatened to shell the launch sites.

The Choco Pie stunt is not an isolated incident. In 2008 South Korean peace activists used helium balloons to send information pamphlets from the south to people in the north. The activists used similar plastic balloons and sophisticated release mechanisms.



Pi In The Sky Telemetry Board Released

Source www.daveakerman.com


High Altitude Ballooning is an increasingly popular hobby (I nearly said that interest has been “ballooning”, but fortunately I stopped myself just in time …), bringing what is termed “near space” within the reach of pretty much anyone who is willing to put in the effort and spend a moderate amount of money.


Although it’s possible to successfully fly and retrieve a balloon with a simple GSM/GPS tracker, the chances are that this will end in failure and tears.  GSM coverage in the UK is nowhere near 100% especially in rural areas which is where we want (and aim) the flights to land.  The next step up, in reliability and price, is a “Spot” tracker which works solely via satellites, but those don’t work if they land upside down.  Also, neither of these solutions will tell you how high the flight got, or record any science data (e.g. temperature, pressure), or indeed tell you anything about the flight until they land.  If you’re lucky.  A lost flight is a sad thing indeed.


For some countries (e.g. USA, but not the UK), if you are a licensed amateur radio operator you can fly an APRS tracker, in which case the flight will be tracked for you via the ground-based APRS network run by other radio hams.  Sadly UK laws prohibit radio hams transmitting from an airborne vehicle, so APRS is out for us.

For these reasons, pretty much everyone involved in the hobby in the UK, and many other countries, uses radio trackers operating in an ISM (Industrial. Scientific and Medical) band where airborne usage is allowed.  These work throughout the flight, transmitting GPS co-ordinates plus temperature and anything else that you can add a sensor for.  Many radio trackers can also send down live images, meaning that you can see what your flight is seeing without having to wait for it to land.  Here’s a diagram showing how telemetry from the flight ends up as a balloon icon on a Google map:


What’s not shown here is that, provided you tell them, the other balloonists will help track for you.  So not only will you be receiving telemetry and images directly via your own radio receiver, but others will do to.  All received data is collated on a server so if you do lose contact with the flight briefly then it doesn’t matter.  However, this does not mean you can leave the tracking up to others!  You’ll need to receive at the launch site (you have to make sure it’s working!) and also in the chase car once it lands.  The expense of doing this is small – a TV dongle for £12 or so will do it, with a £15 aerial and a laptop, ideally with a 3G dongle or tethered to a phone.

Traditionally, balloonists build their own radio trackers, and for anyone with the skills or the time and ability to learn programming and some digital electronics, this is definitely the most rewarding route to take.  Imagine receiving pictures of the Earth from 30km up, using a piece of kit that you designed and built and programmed!  So if you are up to this challenge (and I suspect that most people reading are) then I recommend that you do just that.  It takes a while, but during the development you’ll have plenty of time to research other aspects of the hobby (how to predict the flight path, and obtain permission, and fill the balloon, etc.).  And when you’re done, you can hold in your hand something that is all your own work and has, to all intents and purposes, been to space.


For some though, it’s just not practical to develop a new tracker.  Or you might be a programming whizz, but not know which end of a soldering iron to pick up.  It was with these people in mind that we (myself and Anthony Stirk – another high altitude balloonist) developed our “Pi In The Sky” telemetry board.  Our principle aim is to enable schools to launch balloon flights with radio trackers, without having to develop the hardware and software first.  It is also our hope that older children and students will write their own software or at least modify the provided (open source) software, perhaps connecting and writing code for extra sensors (the board has an i2c connection for add-ons).

The board and software are based on what I’ve been flying since my first “Pi In The Sky “flight over 2 years ago, so the technology has been very well proven (approximately 18 flights and no losses other than deliberate ones!).  So far the board itself has clocked up 5 successful flights, with the released open-source software on 3 of those.  Here’s the board mounted to a model B (though we very strongly recommend use of a model A):

pits (1)It comes in a kit complete with a GPS antenna, SMA pigtail (from which you can easily make your own radio aerial), stand-offs for a rigid mounting to the Pi board, and battery connectors.  Software is on https://github.com/piinthesky, with installation instructions at http://www.pi-in-the-sky.com/index.php?id=support, or there is a pre-built SD card image for the tragically lazy.  We do recommend manual installation as you’ll learn a lot.

By now you’re probably itching to buy a board and go fly it next weekend.  Please don’t.  Well, buy the board by all means, but from the moment you decide that this is the project for you, you should task yourself with finding out all you can about how to make your flight a safe success.  For a start, this means learning about applying for flight permission (which, if you want to launch from your garden at the end of an airport runway, isn’t going to be given).  Permission is provided together with a NOTAM (NOtice To AirMen) which tells said pilots what/where/when your launch will be, so they can take a different path.  You also need to learn about predicting the flight path so that it lands well away from towns or cities or motorways or airports.  I hope I don’t need to explain how important all of this is.


There’s lots more to learn about too, for example:

  • How to track the flight
  • How to fill a balloon
  • Where to buy the balloon
  • What size balloon?  What size parachute?  How to tie it all together?

None of this is complicated (it’s not, ahem “rocket science”), but there is a lot to know.  Don’t be surprised if the time between “I’ll do it!” and “Wow, I did it!” is measured in months.  Several of them.  In fact, worry if it’s less than that – this research takes time.  We will be producing some teaching materials, but meantime please see the following links:

As for the board, it provides a number of features borne out of a large number of successful flights:

  • Efficient built-in power regulator providing run time of over 20 hours from 4 AA cells (using a model A Pi)
  • Highly sensitive UBlox GPS receiver approved for altitudes up to 50km
  • Temperature compensated, license-free (Europe) frequency agile, 434MHz radio transmitter
  • Temperature sensor
  • Battery voltage monitoring
  • Sockets for external i2c devices, analog input, external temperature sensor
  • Allows use of Raspbery Pi camera
  • Mounting holes and spacers for a solid connection to the Pi

The open-source software provides these features:

  • Radio telemetry with GPS and sensor data using UKHAS standard
  • Radio image download using SSDV standard
  • Multi-threaded to maximize use of the radio bandwidth
  • Variable image size according to altitude
  • Stores full-definition images as well as smaller transmitted images
  • Automatically chooses better images for download
  • Configurable via text file in the Windows-visible partition of the SD card
  • Supplied as github repository with instructions, or SD card image

Finally, anyone interested in high altitude ballooning, using our board or not, should come to the UKHAS Conference on 16th August 2014 at the University of Greenwich.  Anthony and I will be presenting our board during the morning sessions, and will run a workshop on the board in the afternoon.  For tickets click here.

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Pi In The Sky Project – Successful Test Flight

This was the third flight of the “Pi In The Sky” board, but the first flight of the new open-source software written specifically for it (previous flights used a modified version of my usual Pi tracker software). The new software is a single multi-threaded program (instead of a collection of separate programs) and is configured via a text file so that for most users no recompilation is needed.

For this flight I used a foam polystyrene egg bought from HobbyCraft. The Pi and tracker board fit neatly inside one half:


whilst the camera, GPS antenna and battery pack fit inside the other. No other packing was needed and the 2 halves were glued together with UHU Por polystyrene adhesive. Here’s the result:



The glue is strong, but just to make sure I put some tape around the egg to keep the halves together.  Here’s the resulting payload, as I start to inflate the balloon:



The launch was easy, and we watched for a while as the flight broke through the clouds and started to download some nice images, after which we set out to chase.  We were expecting the flight to land east of Ludlow, and we initially stopped near Leominster till the balloon turned west, then nearer Tenbury Wells as we waited for the burst.  That happened at 31644 metres, nearly 2km above the calculated figure, and pretty good for a 500g balloon.  Here’s the full flight path:


We were about 3 miles away when it landed, which isn’t bad considering the narrow winding roads in the area.  Landing spot was 4.5 miles from the prediction which is also pretty good.  Once it landed we headed for the last position, and when about half a mile away we received a signal strong enough to decode.  We then had the final position which was near a farmhouse:


We parked up and spoke to a farm worker and then the farmer who was very helpful, allowing us to wander round trying to find the payload.  Initially we went to the wrong place, having transcribed the co-ordinates wrongly!  So we went back to the car, got the correct position, and checked the view from the payload’s camera which the farmer recognized:


Once we had that information it only took a couple of minutes to locate the flight, which was on the ground with the line going over a bush.

So, a successful first flight for the new software and third flight for the new board.  There’ll be another test flight soon, hopefully next weekend.  Meanwhile, some photos from the flight:



HAB flight for all in one Raspberry Pi tracker, camera, and locator

Andrew Huff, student at The Grammar School Leeds, has shown how the Raspberry Pi cut down computer can be used for an all in one offline tracker, camera, and GSM locator for high altitude balloon flights.

Andrew picks up the story in his own words.

Six months ago, after being fooled by the “free computers” sign on my
computing teachers door and receiving a credit card sized Raspberry Pi
computer, I then had to prove myself to be “worthy” of receiving this
£20 Linux PC. So, no sooner said than done I decided to take on the
daddy of all Pi projects – to send it up 90 thousand feet into near space.

I’ve seen the photos countless times before, a cloud covered sphere with
a thin blue haze, glowing against the backdrop of space and yet I still
wanted to replicate it myself to see if this weird, soundless place
really did exist for someone like me, who doesn’t usually receive NASA
funding. Better still, to be able to reach this place with something
which I made and understand myself, captivated me and so from this point
on, I set out to create and program a Raspberry Pi which would be
capable of recording flight data, taking photos and most importantly
being able to send me its position afterwards so that I could collect it.

David Ackerman, the first person to use a Pi for high altitude
ballooning and the many other micro-controllers which preceded mine, all
used armature radio to track down and receive data from the payload. The
benefits of using radio to track the Pi would be that I would be able to
follow it for the entire period that it is in the air and the coverage
is allot better than the patchy GSM network which I settled upon using.
However, as I found out, understanding and then using radio to track the
Pi is allot more complex than just sending an SMS though a mobile dongle
so I soon settled on using that instead.

andrew pi

The next problem came from having to interface with the GPS module.
Before I started this project, all my programming experience was writing
small space-invaders games in BBC BASIC and so having to send binary
and hex commands to an external device was a real shock, which took me a
few days and allot of headaches to figure out. The good news though, is
that after I finally cracked it, I had a much deeper understanding of
how and why the technology worked which was a far cry from the “copy and
paste someone else’s code” approach which I honestly thought this
project would be at the beginning.

As the project grew in complexity, so did my ambitions and so I decided
to add a thermometer to the Pi to see just how cold it gets up there
(and FYI. the pilot isn’t lying when he announces that it’s -50 outside
the aircraft). Although simple to code, the thermometer taught me
another important life skill which was soldering – my new favourite way
of joining anything! All the information on how to do this was readily
available online and it’s well worth doing since it leaves you with a
warm, glowing sense of accomplishment inside, that what you have just
fused together will never ever fall apart. (Just kidding, I’m not that
strange :)

Finally, came launch day. Chris and I set up our equipment and after
filling the balloon and giving an on the fly briefing to our small crowd
of spectators, I let it loose to ascend into that mysterious world which
I first was hooked by over six months ago. I was nervous yet at the same
time proud and satisfied that something which I built was hanging there,
in Arctic temperatures and in an atmosphere one twentieth of what I was
in at that time, beeping and flashing away all on its own, suspended
above a 26km plummet to the earth. But of course, it wouldn’t stay that
way for long. After the inevitable “pop” the real action took place and
as we raced across Yorkshire and Lancashire, finally came the
“ba,da,ding” from my phone which I was praying for. We drove to the last
known location and sure enough, Chris spotted the payload in the middle
of a field between two power lines and a wood. Unfortunately, on impact
the Pi had disconnected its self from the power and so that’s why in
actual fact, we ended up using the backup tracker to pinpoint its
precise landing spot. However, none of this really mattered because in
the end I had proved to myself that I was able to get into near space
and back again using only my year and a half’s computing GCSE course and
a £20 PC.


But that’s only half of the storey, this project went allot deeper than
just computing. I had to organise CAA permits, secure landowner
permission, talk to Professors, convince the school’s marketing
department to fund me and finally be lucky enough to get in touch with
Chris who helped me an indescribable amount to shape the project into
what it has successfully become. In total, what had started off as a small computing idea, has grown into an irreplaceable learning
experience with far reaching benefits for a sixteen year old student
like me.

Irish Sea