The Search for our Missing Balloon: Closing in on the Landing Zone

In late May, Jared Sabater of Soleil Multimedia and I launched a high altitude balloon from south Chapel Hill, North Carolina. The balloon was carrying three cameras to capture spectacular high resolution video images of North Carolina from 20 miles in the air. We also expect to see the black sky of near space and a slightly curved horizon. However, the satellite tracker package fell off immediately after launch, and the balloon — cameras in tow — disappeared into the sky.

We set off to the expected landing zone — Harnett County, North Carolina. Needless to say, the search made looking for a needle in a haystack sound easy, and we returned home with nothing. I posted a desperate plea on my blog (read it here) and crossed my fingers, hoping someone would find the payload and get in contact with me. A reporter from the Daily Record in Dunn, North Carolina, came across my blog post and wrote a story about it.  A day later, I got a call from a woman living in Coats, North Carolina.

“I saw your balloon,” she said.

I didn’t believe her at first.  The balloon was supposed to pop in the stratosphere, not come down intact.  She said she saw it at sunset, a full twelve hours after launch — I figured it should have been way out in the Atlantic by then.  But as she described what she saw, I realized that there were only two possibilities:
1.  She saw our balloon.

2.  Someone else launched a high altitude balloon that just happened to come down in Coats.

The probability of #2 is vanishingly small — smaller even than #1, so I was forced to conclude that, in fact, our balloon was somewhere by Coats.  Jared, my friend Xiao, and I drive out to Coats to talk with the witness.  She was wonderfully nice and amazingly observant.  We stood by the window from which she saw the balloon, and she started telling me what she saw.  First of all, her pastor had also seen it crossing a road to the north, so we had a bearing.  Second, she said it had something sticking off to the side.  Third, it had remained in the same place for about an hour.

I didn’t know what to make of the second and third statements.  Balloons don’t fly with things sticking sideways, that makes them unbalanced and they tend to rotate so that whatever it is sticks straight down.  Also, even when the wind is imperceptible at the Earth’s surface, it’s strong enough above the surface to move the balloon out of her viewing area in less than an hour.

That’s when I realized what she’d seen:  Our balloon had already landed by the time she glanced out her window!!

It was simple in retrospect.  By the time the witness looked out her window and saw the balloon, the payload was on the ground or snagged in a tree.  The balloon envelope was still buoyant, hanging above the landing site like a giant flag — pulled slightly sideways and hooked over by the wind (hence the thing sticking out) and more or less stationary (why she was able to see it for an hour in the same place).

Here’s what we know right now:

The balloon envelope is cream to reddish colored and probably up to 20′ across.  It’s likely shredded into bits due to UV light and wind action.  The payload is 40′ from the envelope in a red lunch box with cameras attached.  The envelope is likely draped over a tree, and the payload is probably in the upper branches of another tree.

The area visible to the witness starts at 35.389756 N latitude, 78.638441 W longitude, and extends due east.  We can define sight boundaries by using buildings and trees that obscure her view to the east and the west (see figures below).

We searched several fields in the sight line and didn’t find anything, so the payload’s likely in forested areas.

Another witness saw the balloon crossing Red Hill Church Road at very low elevation, heading towards the first witness’ house, so that road defines a hard eastern boundary to the search area.

The first witness says the balloon was west of Black River – this provides another search area boundary, but with less confidence.

Elevation profiles (see below) and distances to the Black River make it even more unlikely that the witness could have seen the balloon on the ground if it were in the Black River valley.

Here are a series of maps of the search area:

view_areaThe red triangle defines the region visible from the first witness’ house, with the east boundary defined from the road which the balloon crossed per the second witness’ description.  Green polygons enclosed regions we were able to search on our first trip out to Coats.  The pale blue arc is 1 mile from the first witness’ house.  It’s hard to imagine being able to make out as much detail as she reported if the balloon is beyond this circle.

Elevation profiles along the north and south sight lines are available here:

north

south

These profiles suggest that the Black River area would be difficult to see from the first witness’ location.

landing_zone

The four yellow polygons show the most likely landing zones based on the analyses described above.  Areas A and B are by far the most probable locations for the payload, based on the witness’ statements and distance from where she saw it.  Any search should carefully investigate these regions.  Area C is also possible, but rather less probable because it is significantly below (and thus probably invisible from) the witness’ house.  Also, it’s quite far away, which would make the details she described hard to see.  Finally Area D cannot be eliminated, but it is the least likely due to elevation and distance.

Our next step is to go out and search.  If you’d like to join, or if you have some other information for us, let us know!

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