Wednesday, August 15, 2007

Pic of SDG-6 in flight

Special thanks to Larry Prelog for this photo of Soli Deo Gloria 6 shortly after launch. Larry also sent some pics of the inflation and these will be posted soon.

Monday, August 13, 2007

Update on SDG-6's overnight stay...

After looking more closely at the area where Soli Deo Gloria 6 came down early on Sunday morning (~3:30am EDT), I think it is likely that the payload did, indeed, come to rest on the ground.

What brought it down? Probably frost - a problem which also plagued Vin Lally's low altitude superpressure balloons back in the '60s and for which no solution was ever found.

The frost would have melted into dew by mid-morning and then, as it evaporated, the balloon would have been able to rise again. The much faster - and earlier - descent on Sunday evening was undoubtedly due to actual loss of gas through pinholes in the envelope. The flight was over by this point, frost or no frost.

SDG-6 Recovered!

SDG-6 has been recovered! This morning I spoke with the gentleman who found the balloon - Mr. Ryan Bryant, a Realtor from Cumberland County, Kentucky.

Mr. Bryant said that he saw the balloon caught on a powerline along Highway 61 North in Cumberland County last night at around 7:30pm Central Time. This was a very fortunate event, since the area is otherwise quite remote.

After he cut the payload line, Mr. Bryant said that the balloon envelope took off into the sky - so its flight wasn't yet over! (Having been relieved of the payload, the envelope would have developed a very high superpressure at altitude and most likely burst within 10-15 minutes of leaving the powerline, so it's probably not too far away.)

The payload is now safe and will be on its way back to Michigan sometime soon... Our thanks go out to Mr. Bryant for a wonderful end to a wonderful flight!
One last bit of flight info... The calculated great-circle distance from the first to last received APRS data points is 298 miles, for an average speed of about nine miles per hour over the total flight time of 32h 26m.

(Note that I used the great-circle calculator at
A quick overview of the Soli Deo Gloria 6 flight before I turn in for the night...

Balloon system description
Type: Superpressure
Env material: Polyester film
Volume: 25 cubic feet
Env mass: ~.8 pounds
Payload: Microtrak 300, Digitraveler, Ultralife 9v lithium battery x2
Payload enclosure: Tyvek mailing envelope, 8.5"x11", with approx. 12"x4" bubble wrap
Payload mass: ~5.5 ounces

Launch details
Launched during Bill Brown's 20th anniversary of amateur radio high-altitude ballooning celebration outside of Findlay, Ohio. Numerous other hams in attendance at the event helped to weigh off and launch the balloon - sorry, I'm terrible with names (if you were there, please add a comment and let me know!)

Flight details
Launch was just after 11:00am on Saturday, 11 August 2007 at approximately 40.9680 N, 83.6228 W. Balloon reached stable float around 7000 feet a short time later. Float altitude slowly dropped to around 6600 feet near nightfall and continued stable until around midnight local time. During this time period the balloon had continued to fly toward the south at around 10 mph. At approximately 3:30am on 12 August 2007, the balloon appears to have dropped within a narrow river valley in northern Kentucky. The packet from this location was the last received until approximately eight hours later, when the balloon again ascended high enough for its signals to be received by other APRS stations. A stable float altitude of approximately 6600 feet was again achieved and maintained until approximately 7:00pm local time, at which point terminal descent began. It appears as though the balloon was on the ground in southern Kentucky by 7:40pm or so at approximately 36.8678 N, 85.3772 W.

Sunday, August 12, 2007

It looks like SDG-6 came down around 7:30pm tonight and - I think - it has been retrieved by someone!

I say this because around 8:20pm I received a cell phone call (which I could not take at the time - I was in the middle of the American Idol concert in Detroit) which appears to be from Cumberland County, Kentucky. While no message was left on my voicemail, this is very close (within a few miles) to where the last packet from the balloon originated - and my cell phone number was on the outside of the payload.

I will call the number back in the morning and then continue the story here.... This has been an amazing flight - over 32 hours in duration - and I have a feeling that the recovery story will be equally amazing!
A very strange flight, this is! About 45 minutes ago, I came down to the computer to see the most recent data from Soli Deo Gloria 6. I was fully expecting that it would be on the ground and, indeed, the last APRS packet received was at about 1100 feet somewhere in Kentucky - and about eight hours old.

It's worth adding at this point that the HYSPLIT model - when set to include vertical winds into the calculation - showed a slow descent to around 1000 feet throughout the night. This contrasts with the isobaric model and, frankly, what I expected. Yet it seems to mirror reality.

Okay, back to the situation... A few minutes later, I click on "Raw APRS data" in Findu to see what happened after I went to bed around midnight. As I scroll down, the last received packet jumps off the screen at me - the balloon is again at altitude!

As of right now, it is flying - either "again" (reascent, which is extremely unlikely) or "still" (I think that it was probably floating very close to the ground, perhaps in a small valley which kept it contained all night).

Anyone who has seen the very fragile payload providing the tracking (Microtrak 300 and Digitraveler GPS - out of the case - just stuck inside of a Tyvek mailing envelope!) knows that there is no way the payload could have been stuck in a tree or anything else and somehow come free this morning (that is, and still work!).

So it's in the air, over 24 hours after launch. Where will it go? I don't know. How long will it fly? Anyone's guess - the answer to this partially depends on WHY it came down last night (was it simply the vertical wind profile, as the HYSPLIT model suggests, or did it lose enough gas to come down yet, somehow, magically keep just enough to reascend upon solar heating?).

I'll be away for most of the day, so it might be a while before there are any more updates - if you have more information about the flight, feel free to post it as a comment!
Well, less than an hour after everything appeared fine, it looks like SDG-6 might be in a terminal descent. Not sure what might have happened at this point - but at this rate, the balloon will be on the ground in an hour or so.

Next update will be in the morning...