UK student balloon crosses Pacific

UBSEDS18 Solar Powered Balloon

UBSEDS18 Solar Powered Balloon

The UK balloon UBSEDS18 carrying payloads for APRS and 434 MHz has successfully crossed the Pacific, on the same day a USA amateur radio APRS balloon crossed the Atlantic.

The solar powered UBSEDS18 was developed by students from Bristol University and launched on Wednesday, August 17. Since then it has traveled in an easterly direction for 20,252 km completing the Pacific crossing on Thursday, September 1, 2016.


The amateur radio APRS balloon CNSP30 was launched from California on August 25 and on September 1 crossed the coast of northern France. Its APRS signal was receivable across central and southern England.


Richard Meadows M0SBU, who worked on the development of UBSEDS18, took the amateur radio training courses run by the Chelmsford Amateur Radio Society (CARS) at Danbury in Essex. Further information on the courses is available from the CARS Training Coordinator, Christopher G0IPU
Tel: 07908-107951
Email: training2016 at

UBSEDS19/20 balloons launch from Bristol

UBSEDS IMG_2406Richard Meadows M0SBU reports two high altitude balloons carrying 434 MHz payloads will launch from Bristol on Monday, August 29. There will be Slow Scan Digital Video (SSDV) transmissions.

Online real-time tracking of UBSEDS balloons!mt=roadmap&mz=8&qm=3_days&q=UBSED*&f=UBSEDS20

We’re planning the first launch of ‘pico-pi’, our Raspberry Pi Zero based tracker, from Bristol this Bank Holiday Monday, August 29 between 0500 and 0530 BST. This launch is using a 1.9m envelope and longer payload train, and so we have a NOTAM in place.

There’s more information about the tracker itself here:

The combined payload mass will be about 70 grams, and the attempted float altitude will be about 13 km. This is our first launch of this setup, so it seems unlikely that everything will go to plan!

First is the UBSEDS19 backup tracker, which is powered from a single AAA Lithium Energiser battery. It transmits Contestia 16/1000 with pips and RSID on 434.615 MHz USB, once per minute below 8km altitude and every two minutes otherwise. The battery is expected to last a few days.

Next is UBSEDS20, which is the experimental Raspberry Pi Zero board. This is powered from solar panels only, and hence is only expected to operate continously after about 0830 BST (before this it may transmit without a GPS lock, as the Raspberry Pi and GPS are powered down).

– 434.610 MHz USB: 300 baud RTTY, 850Hz shift, 8N2 transmitting telemetry and SSDV. There is also Contestia 16/1000 with RSID on this frequency. If you are listening to the RTTY, remember to turn off the ‘RxID’ button on the top right of dl-fldigi.

– 869.85 MHZ LoRa ‘Mode 3’ (250kHz / SF7 / EC4:6, explicit header), transmitting SSDV with the callsign ‘UBSEDL’. This frequency is only active in Europe. Many thanks to Dave Akerman M0RPI for making his work on LoRa available for us to use, including the lora gateway.

Rather than the usual JPEG SSDV, this payload is transmitting Better Portable Graphics (BPG) images. This is experimental, and doesn’t support it just yet. Hence receivers should upload to instead, please read the instructions on this site. You’ll need dl-fldigi release 3.2 and slightly modified LoRa gateway, as explained on the site. The dl-fldigi release can be found here:

Many thanks to everyone who attempts to track these.

Richard Meadows M0SBU
Bristol SEDS

Useful balloon links

Richard took the amateur radio courses run by the Chelmsford Amateur Radio Society (CARS) at Danbury in Essex. Further information on the courses is available from the CARS Training Coordinator, Christopher G0IPU
Tel: 07908-107951
Email: training2016 at

UKHAS Conference Cambridge


SSDV picture from a PIE balloon – Image credit Dave Akerman M0RPI

There’s an impressive line-up of radio amateurs among those giving presentations at the UK High Altitude Society (UKHAS) conference in Cambridge on Saturday, September 10, 2016.

Watch Live at


The conference takes place at the Institute of Astronomy, University of Cambridge and attracts those interested in learning about building and flying High Altitude Balloons or in tracking their 434 MHz signals.

Tickets can be purchased from the wiki page and cost just £10 each.

Provisional Schedule as at August 16:
09:30     Assembly – Drinks & Biscuits
10:00     Welcome & Introduction
10:10     LoRa – Dave Akerman M0RPI
10:40     Evidence that Biology is Continually Arriving to Earth from Space – Prof Milton Wainwright (Univ. of Sheffield)
11:10     Operation Outward – Steve Randall G8KHW
11:40     Break
12:00     Chase & Recovery – Dave Akerman M0RPI
12:30     VORTEX Parachute Tests – John Underwood
13:00     Lunch
14:00     CUSF’s Martlet Rockets – Adam Greig M0RND
14:30     Introducing AirCores – Dr Johannes Laube (UEA)
15:00     Scheduled Talk Subject to Official Approval
15:30     Break
15:45     500 cu m Solar Balloon Project – Sven Steudte DL7AD
16:15     Superpressure Maths & Envelope Construction – Richard Meadows M0SBU (UBSEDS)
16:45     End

UKHAS were offering the option to complete the amateur radio Foundation Practical Assessments and Exam at the conference. This was rapidly fully booked, perhaps a sign of the shortage of Foundation exams venues.

If you would like to speak or run a workshop, please do get in touch with either Daniel Saul M6DSA or Steve Randall G8KHW. Contributions don’t need to be directly linked to ballooning and they look forward to all suggestions.

Conference registration information is at

Probable UKHASnet launch May 21/22

UKHASnet LogoJames Coxon M6JCX reports he is hoping to launch a UKHASnet node from East Anglia this weekend.

On the UKHAS Google Group he writes:

I’ve put together a GPS enabled, temperature controlled node AJ2 which will be launched on a latex balloon (rather than pico).

Due to the pattern of the winds the aim will be to float the balloon at around 30-35 km and current predictions suggest that it’ll drift east first then turn around and come back across the UK travelling west. This should give pretty good coverage of the UK and at a push across the sea towards the Netherlands so it would be great if any UKHASnet nodes could be brought online.

The node itself will be in repeater mode as well as transmitting its own packets every 30 seconds with GPS and other data. Previous tests and flights have had a mixture of results, the EMF launch allowed for 65 km downlink range and recent tests on the IoW made a solid 2 way link over 18 km however other flights haven’t been successful. Hopefully the temperature control will stabilise the radio to stop it drifting too much (both on tx and rx) and the node will recalibrate its noise floor etc as well as reset the rx loop of the radio to stop it locking up (a previous issue). The more nodes that we can have online the better (it is even possible to setup an RTLSDR dongle as a UKHASnet gateway)

There will be a backup tracker providing a RTTY downlink on 434.300 MHz (Atlas) which will be uploaded to This will be RTTY, ASCII 7, 425 Hz shift and is an old pAVA R7 board with a RFM22 so be prepared for some drift.

Current plan is to launch around 1100 on Sat 21/05/16 though the window will be the whole weekend and launch will be from Preston St Mary, Suffolk.

Flight data will be on the UKHASnet map

I’ve made a grafana page for the node
and as always there will be discussions on #ukhasnet on freenode.



Useful High Altitude Balloon links

Schools in mass launch of 434 MHz balloons

Successfully launched tracked and retrieved - Credit Hobb Computer Services

Successfully launched tracked and retrieved – Credit Hobb Computer Services

TV presenter Jason Bradbury 2E0JAB was among those present at a mass launch of 25 balloons transmitting in 434 MHz on Thursday, May 12, 2016.

Tracks of some of the balloons - Credit PitsProject

Tracks of some of the balloons – Credit PitsProject

Balloons from 25 schools were launched in batches of five from RAF Cosford. Each balloon carried a payload incorporating two small cameras and the Raspberry Pi In The Sky telemetry tracker. The balloons transmitted on unique frequencies ranging from 434.040 to 434.790 MHz.

Jason Bradbury’s balloon reached an altitude of 33 km before it burst and the payload parachuted back to Earth. The next problem was finding it. He tweeted:

Call out to my radio amateur friends. Need help finding 434.04mhz telemetry binary code

The balloon was eventually found stuck up a tall tree.

Watch the BBC TV Midlands Today report on the event

The Sentinel newspaper report – Students are flying high as experiment takes them to the edge of space

Pi In The Sky telemetry board

Sent into Space

Useful High Altitude Balloon links

Getting ready for the launch - Credit KMF Metal

Getting ready for the launch – Credit KMF Metal

UBSEDS14 balloon flying across Pacific

UBSEDS14 balloon flight track as at March 14, 2016

UBSEDS14 balloon flight track as at March 14, 2016

On Monday, March 14 the UBSEDS14 balloon, launched by University of Bristol students, passed over Japan and out towards the Pacific, having traveled over 15,497 km since launch.

The University of Bristol Students for the Exploration and Development of Space (UBSEDS) launched their balloon on Monday, March 8. Powered by a single AA Lithium Energiser Battery (LR91) the balloon has been transmitting about 5dBm of Contestia 16/1000 on 434.600 MHz USB at 4 minute intervals as well as APRS during its flight at an altitude of about 11,000m.

The balloon has a diameter of 1.5m and the payload weighs just 21.3 grams. Despite the weight constraints the team have managed to employ sophisticated Geofencing technology to prevent the balloon transmitting when over certain countries and also to select different APRS frequencies depending on the territory being overflown.

UBSEDS14 information is available at

UBSEDS14 balloon launch

Useful High Altitude Balloon Links

One of the students involved in the project is Richard Meadows M0SBU. He took the amateur radio courses run by the Chelmsford Amateur Radio Society (CARS) at Danbury in Essex. Further information on the courses is available from the CARS Training Manager
Email: training2016 at

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