On the SPOT: David G. Simmons

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Our friend EDGAR

Friday Apr 11, 2008

I have a long list of topics I have to catch up on, so please bear with me. One of the fun things we do around here is what we used to refer to as our 'Friday Projects.' Somehow they usually manage to get us into some sort of trouble, and often they take longer than a Friday.

EDGAR managed to only do one of those things -- take longer than a Friday. Sadly, given how completely underwater I have been with other mundane and less-interesting tasks, I was not able to participate in most of the preparatory work for EDGAR, but I was able to be there for the launch. It managed, somehow, and even though it has to rank as one of our more danger-laden capers, to not land us in any trouble, either with the powers-that-be at Sun (at least so far :-) ), or with various government agencies -- and it had real potential on that front.

So the back-story ... A few months ago (I may have even posted it here, but since I'm blogging from 33,000 feet, I can't check) we found a website where some guy launched a weather balloon, complete with sensors and camera, to 70,000 feet. The pictures were amazing, and it seemed like a cool thing to try. And EDGAR was born.

As usually happens with our hair-brained schemes, the project quickly ballooned out of control, taking on a life of its own. We recruited internet volunteers, and even got Sun's own Charlie Jackson (our intrepid Web Designer/guru) to pilot a chase-plane (though I suspect he just wanted to go flying and this was his excuse).

The Team (which, I will point out again, did not really include me, except peripherally) designed a payload with a Sun SPOT, and an APRS Radio, for tracking and data gathering. I arrived in time to at least watch the final preparations of the payload. We walked it around MPK Campus to test some things out. It looked a tad fragile outside the payload, but it worked:

"Go ahead, I dare you to take that into an airport ..."

That's Arshan, and Tennessee walking the beast around the campus to test the radio. Part of the testing also included beer, of course:

mmmm beer

After all, who knows exactly what we might encounter in the upper atmosphere, right? For all we know (having never been there) there's a kegger going on. Turns out we still don't know, but I'll get to that.

So, all the testing done, we decided to launch from down near Holister, CA (nothing to do with that silly clothing that's all the rage these days). By the calculations that Tennessee did, we expected our balloon to rise at approximately 600 - 700 feet per minute, to a pre-determined altitude of between 70,000 and 80,000 feet before the Sun SPOT triggered the balloon to be cut free, the parachute to deploy, and our payload to come screaming back to earth at roughly 1,000 feet per minute. All the while taking pictures and collecting data. The payload should touch-down over near Visalia in the central valley about an hour and a half after launch.

That was the plan. Amazingly enough, it's pretty much what happened. Most of us gathered in a field outside San Juan Bautista and began preparing for launch while the chase-plane team got in the air and the recovery team high-tailed it for the central valley to meet the payload.

We're out standing in our field

As you can see, we were well within the less than 50% cloud cover required for launch. Of course. Arshan made some final software preparations, in consultation with our resident radio expert Glenn Scott.

"I'm telling you ... "

By the look of it, we don't want to know the exact nature of the consultations.

"No, seriously, that'll never work."

I have to say that I have no pictures of the actual launch, etc. as I was rather busy at the time (in my Playtex Living Gloves) actually inflating the balloon and launching it. However, we had a large collection of 'documentarians' around snapping away furiously. So feel free to visit some of their pictures:

Launching the balloon was a blast. Who knew that just letting a balloon filled with lighter-than-air gas could be such a ... gas! We tracked it as long as we could with the binoculars and the telescope, and then set off on the chase.

After an hour's drive (or so) through the Central Mountains of California, we met up with the recovery team. Amazingly enough, they had parked and waited for the return package, and it landed within about 1 km of them, and their predictions of where it would land. Here is the happy team with the successfully recovered EDGAR payload:

That's George, Lach, Bones, Tennessee and Arshan

We were all smiles an high fives. Then we opened the payload to retrieve the camera and data-collection SPOTs:

It takes many hands to extract the payload

Yep, it's all still there. No one stole it while it was up there.

Everything inside was in fine shape. A little ice here and there, and very cold still, but no damage. By the tracking data we got from the APRS radio, we knew that the balloon had flown much higher than we expected, to almost 90,000 feet. We also knew that the mechanism to cut the balloon free had not functioned properly, since pieces of the tattered, burst balloon were still attached.

We were very disappointed to find that, apparently, we had done something wrong in the packaging of the payload prior to launch, and the Sun SPOT was not powered on. So we got no data, and no pictures. Disappointing as those things were (are), we were still excited by the success of launching and recovering the balloon and its payload. We can fix the rest in software.

So we were all set to begin preparing for a follow-on launch -- EDGAR-2, but it turns out that while we were out doing our launch, our good friends at Warren-Wilson college had, literally, turned green with envy and deployed EDGAR-2. So now we have to go to EDGAR-3.

If you're interested in participating, this is an 'open' project. We are recruiting anyone who's interested. Just join us over at http://groups.google.com/group/spotballoonand let's see if we can't collect data this time. I'm especially interested in capturing pictures, so I'm working on a new payload container with a moveable camera in hopes that we can get lots of pictures this time.

So join us. Let's make EDGAR-3 even more successful than EDGAR-1. Given the competition from EDGAR-2, we have our work cut out for us.

[ "How do I love thee? My accumulator overflows." ]

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