Monday, April 23, 2012

A new link to my (now archived) school web page: Information on a new flight coming soon - really!

Friday, March 25, 2011

SDG-10 flight imminent

After a LONG delay, SDG-10 is again close to launch. More details will be posted over the next few days!

Wednesday, October 14, 2009

SDG-10 postponed due to weather

The predictions for in-flight weather have only gotten worse, so this flight will be postponed. We hope to fly before the month is over. Please watch for updates.

Tuesday, October 13, 2009

SDG-10 flight tentatively scheduled

Soli Deo Gloria 10 is tentatively scheduled to fly tomorrow,15 October 2009, at 0400 UTC. The APRS tracker will not be carried: the payload will consist of a KA2QPG HF beacon similar to previous superpressure flights.

More details tomorrow if the flight remains on schedule.

Friday, October 2, 2009

SDG-10 APRS tracker testing underway

SDG-10 will most likely carry a Microtrak-based APRS unit. Testing is currently underway, so don't be surprised if you see KC8UCH-11 on the network. It's not flying yet, though - it's just sitting in a fourth-floor window of the school!

Thursday, October 1, 2009

Superpressure balloon SDG-10 to fly in October!

Soli Deo Gloria 10 - now with a redesigned superpressure envelope - will fly sometime this month. This will be a trans-Atlantic attempt and will most likely carry a high frequency beacon like earlier flights.

Stay tuned for more details in the next week or so...

Robert KC8UCH

Sunday, April 6, 2008

SDG-10 postponed

Projections don't look good for today, so the flight will be postponed. Stay tuned!

Saturday, April 5, 2008

SDG-10 on hold until Sunday

Due to a technical problem with the balloon, Soli Deo Gloria 10 is on hold until tomorrow evening. Sorry for the late notice - we were still hoping to launch tonight, but the predictions now show that we couldn't make landfall before the ballast is exhausted.

We will try again tomorrow evening. Also, it looks like we will be flying an APRS tracker after all - so we will be looking for European APRS users who would be willing to tune their radios down to 144.39 Mhz for a day or so.

More information tomorrow. Again, sorry for the late notice.


SDG-10 payload update

We will definitely fly the 10 metre beacon, transmitting CW on 29.499 Mhz. This beacon is identical to that flown on SDG-9, with the exception of one telemetry field.

If you are along the flight path shown below and can monitor 29.499 for us later tonight (for U.S. listeners) or the evening of 07 April (for European listeners), please do so!

Soli Deo Gloria 10 flight announcement

Tonight, at 0200 UTC on 06 April, we will launch Soli Deo Gloria 10. This flight is another trans-Atlantic attempt by KC8UCH and KA2QPG but, unlike previous attempts, this will be a zero-pressure flight with ballast drop.

The image to the right shows the trajectory predictions for this flight - we plan to fly along the blue line. The big dot near the end of each line (in Europe/Africa) represents 0000 UTC on 08 April - SDG-10 should be on the ground (or in the water) by then.

The big question at the moment is which payload we will be flying. It will either be an APRS tracker on 144.39 Mhz (which will require European stations to tune down to that frequency for us) or another 10 metre beacon on 29.499 Mhz. If you are in southern Europe (preferably southern Spain) and would be willing to tune your APRS station over to 144.39 for us, please let us know right away!

More details will be announced as we get closer to flight time. There's much to do between now and then....


Tuesday, March 25, 2008

Soli Deo Gloria 9 mission over

Other than post-analysis of the Annapolis pass, the mission is over. Even if the balloon is still flying (this particular balloon has a theoretical lifespan of around 21 days), the transmitter should be silent by now. The image at right shows the final trajectory prediction, this time going far beyond the life of the batteries.

Many thanks to all who have contributed to this flight. Please stay tuned for Soli Deo Gloria 10 in the coming days!

Robert KC8UCH

SDG-9 - any signal reports?

We have this from SV1KU:

from wl KM17UX
AT 080324 1430Z QRG 29.498.84 QSA 1
AT 080324 1830Z QRG 29.497.00 QSA 1
AT 080314 1930Z QRG 29.496.87 QSA 1
AT 080325 0830Z QRG 29.497.88 QSA 1/0
Engine of Logger 32. gb de sv1ku.

Other than that, only a couple of "nothing heard" reports. Anyone else logging last night? If so - and you see something of interest - please let us know. Otherwise, we're about to pull the plug on SDG-9, as the batteries should be just about exhausted by now.

Thanks and 73,

Monday, March 24, 2008

SDG-9 final prediction

The image to the right is the latest - and most likely last - HYSPLIT prediction for the SDG-9 flight. The end of the red line (north of Scotland) indicates where the transmitter's battery will likely die, all of this assuming that the balloon is still aloft.

Note the time scale at the bottom of the image - the end of the line is at 1200UTC today, 25 March. Will the balloon be within range for someone to hear it by this time? I simply do not know.

I have written to several amateur operators in Greenland and Iceland but, as yet, have received no replies. Will it be close enough to the UK to be heard? I have no idea - but I encourage amateurs in the UK to listen closely over the next ten hours and see if you can hear anything.

Thanks again to everyone who has taken the time to listen or drop us a line - and please check back for further updates, including details on the balloon design used in this mission.



SDG-9 update

It is now nearly 1800z on the 24th and the possibilities are narrowing - either SDG-9 is down, or it is flying at around 8km.

The latter is entirely possible and fits well with the temperature data that was received by WB2YDS early in the flight. This lower altitude also greatly increases the chance of frost downing the balloon, but it could still be flying. Were it at the design altitude of 9-10km, then it should already be over Spain at this point (extremely unlikely, unless the transmitter has somehow failed).

If it is still flying and at 8km, then it should be over Greenland right now and about 12 hours away from the UK. Keep listening, folks - it isn't over quite yet!

73 and thanks to all for your help,
Robert KC8UCH

Europe still possible - and many thanks to SNOX!

First, although there have been no reports of the beacon in England or other parts of Europe yet, it is still possible that the balloon is flying at a lower than predicted altitude and thus could be delayed by as much as 20 hours over earlier estimates.

One station, M0XAP in Essex, reported hearing an "S" and a "G" in CW whilst monitoring 29.495 on USB at around 11:45 today - this could be nothing or, perhaps, this was the beacon (the "S" might have been part of a number in the telemetry string). England, please keep listening!

If we still have nothing in another day, then we can assume that the balloon probably met a cold, icy end... If the original float was closer to 8km than 9km, then it might have picked up significant frost over northern Canada or even Greenland. This would have forced the balloon to the ground, ending the mission.

I want to reiterate, though, that we simply don't know at this point and it is still entirely likely that the balloon will be heard in Europe. So please, keep monitoring 29.499 (and lower after sunset, possibly down by as much as 3khz).

Many, many thanks to Dan Bowen and the SNOX team for passing along our information to their listening network in Europe!

Sunday, March 23, 2008

SDG-9 European alert

Assuming that SDG-9 is still flying at this time, it is possible that stations in England may be within listening range at any time in the next 24 to 36 hours.

That is, given the ambiguity about the balloon's exact altitude and thus trajectory, it could be within range of England now or it might not arrive for another day or so. Once it is within range of a given station, it will probably be readable for four to six hours at most. So if you have the ability to set up Spectran or some other recording software, now would be the time to do it. A gap of four hours could cause you to miss the balloon entirely.

Assuming that we make it to England, the next passover would be Spain. Please see the image in the previous post for more information on possible trajectories.

NB: After a long night at -45C, the frequency of the transmitter will most likely have been shifted significantly downward (WB2YDS noted a drop from 29.499 to 29.496 Mhz as the payload temperature dropped from -9C to -40C after sunset on the first day of the flight).

If you hear it at all, please drop me a line at!

Thanks and 73,

SDG-9 update and European timeline

So far, I have only heard back from one individual in Newfoundland and, as noted in my previous entry, he did not hear the beacon. It seems we've come up with a twist to the old "tree falls" riddle: "If a beacon flies on a balloon and no one is around to hear it, does it make any sound?"

There are three distinct possibilities as to what has happened to SDG-9:

1. It had pinholes or other defects and subsequently lost gas, causing it to descend.

2. Radiative losses during the night cooled the gas sufficiently to offset the initial superpressure and decrease the balloon's volume, causing it to descend.

3. It is still flying.

The first alternative is certainly possible, but earlier SDG flights have demonstrated that our three-layer film is capable of holding gas under pressure for at least 32 hours (our previous flight record). It could have lost gas due to a mechanical defect, but I doubt it.

The second alternative is what most likely cut many of our earlier flights short. In particular, SDG-6, the 32 hour flight, almost certainly suffered from radiative losses and subsequent contraction of the gas (and loss of lift) when it descended the first night. I believe that we have corrected this problem, however, by almost doubling our initial superpressure compared to our earlier balloons (from 5% to 10%).

The third possibility - that it is still flying - is certainly my fondest hope and it is entirely likely. If so, then, save any possible listeners in Greenland (are there amateur radio ops in Greenland?), the next place where it might be heard is Iceland and, thereafter, Scotland.

Assuming that the balloon reached stable float at 9km, it should pass Iceland between 1800z today and 0000z on the 24th. It should then reach Scotland about four hours later, at 0400z on 24 March.

If stable float was indeed at 10km - which I doubt - then it will be a bit behind that schedule, nearing Iceland at 0400z on the 24th and Scotland several hours later.

The accompanying HYSPLIT projection (click it to see a larger image) shows trajectories for 8, 9 and 10km altitudes to battery exhaustion, about 96 hours after launch. Note that the 8km trajectory still leads to Europe, but quite a bit later. (Note the time scale along the bottom of the image.)

Please, if you can spare any time at all this Easter to monitor 29.499 Mhz for our CW signal, please do so! Without listeners, the balloon could easily fly over continental Europe and no one would even know! Note that the frequency tends to drop a bit after local sunset for the balloon, so keep this in mind when listening.

We gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website ( used in the accompanying trajectory projection.

Saturday, March 22, 2008

SDG-9 - nothing yet from Newfoundland

Dan, VO1MX, reports nothing heard so far in Newfoundland. Not necessarily bad news, since the balloon would have been almost 200 miles from Dan when he started listening and he reported S7-8 noise on the frequency. So it could be there and simply too weak for him to hear.

If anyone in Newfoundland is reading this right now, please listen to 29.499 Mhz right now and see if you can hear the beacon! Even if it is there right now, it will be moving very fast and the chance to hear it will be quickly over.

Thanks to all who have written and asked about it... We remain hopeful and welcome any reports.

Possible SDG-9 trajectories

Here are three possible trajectories for SDG-9 as of 1900z today. It should be audible in Newfoundland right now if it is flying at 9-10km, otherwise it is unlikely to be heard by anyone for a while.

Beacon details for SDG-9

The beacon is transmitting the following string on 29.499 Mhz using conventional CW:


Where the number following "F" is the frame counter, incrementing with each transmission, and the number following "A" is a numeric code representing temperature. Below is a table of numeric values and associated temperatures in Celsius.


Note that both the "A" value and the frequency of the beacon will drift significantly downward after local sunset for the balloon.

SDG-9 update

Tom, WB2YDS, is on Long Island and copied a good deal of telemetry last night before the balloon went over his horizon. Sunset was clearly visible in the data, as the internal temperature plummeted and the frequency of the transmitter drifted downward. The temperatures copied by Tom ranged from -9C at 2138z, down to -41C at 2322z.

The last two strings that he copied (at 2314z and 2322z) seemed to show the temperature leveling off at around -40C, which would indicate a float about 2km lower than the designed float altitude. If this is indeed the case, then we could have some problems - 2km lower means that we will run into a good deal more moisture on our northern voyage and possibly pick up ice. Just a bit lower yet - at around 7.5km in altitude - the entire trajectory changes and the balloon ends up floating aimlessly in the doldrums.

On the other hand, Pierre, KA2QPG, the designer of the beacon and my cohort in this endeavour, points out that the beacon itself gives off about 100mW of heat and could be skewing the internal temperature a bit. If so, then we could still be at 9-10km and heading in the right direction. We'll see.

At around 1800z today, *if* the balloon is on the right trajectory, it should be passing Newfoundland at about two hundred miles off the east coast. I've alerted some amateur radio ops in NL and they will be listening!

Friday, March 21, 2008

SDG-9 Update

Bob Bruninga has lost the signal as of 1753 EDT. Tom, WB2YDS, reported copying the signal at 1738 EDT on Long Island. Still analyzing the data from both - if you have any further data, please send it our way!

Below is a link to a short YouTube video of the balloon and payload shortly after launch. Sorry, no better pics or video of the actual launch are extant (my 12 year old son and I were a little busy with the launch itself - I pulled the camera out of my pocket as soon as I could!).
Update: Bob Bruninga, the father of APRS, is hearing the beacon in Annapolis!

Now if the balloon can survive sundown in a few hours (were those pinholes sealed or not?!), perhaps we can look forward to the 48 hour flight projection shown below... Any listeners to the north?

SDG-9 projected flight path after reaching stable float at 10km - note that the times are about 30 minutes behind real-time:

Monday, September 10, 2007

SDG-7 recovery map

Here is a small map showing the approximate location of "splash down" in Lake St. Clair and then where the payload was recovered on the shores of Lake Erie.