NSL-33

Lost at sea ?

NSL-33 was launched the morning of Nov 30, 2014 to test a very small APRS tracker and camera combination. It left Asheville, NC around 1025EDT for a landing around Raleigh 4.5 hours later. Right from the start something wasn't right. Although we should have had an ascent rate of 3.2m/s, the payload only climbed at 1.8m/s.

And then... about 45 minutes into the flight, we lost tracking.

So maybe in a few months it will wash up somewhere interesting

Initial ascent after launch was around 1m/s. Ground video shows that during this time, the under-hung chute was not deployed.

For a couple of minutes, from 6000-7000ft, it ascended at 3.2m/s. At 7100ft it actually blew downwards for a minute. Then it settled into to an average 1.8m/s climb until loss of signal.

Mystery #1: Video of the launch prep shows that the balloon was filled so that it was positively buoyant with a 438g filler tube attached. The filler tube was removed, along with 11g of extra neck latex. Then the payload, chute, string, tape, wire ties, etc.; totaling 139g, was attached. So the ascent rate on that calm morning should have been > 3m/s. So, what contributed to the slow ascent rate? Even if the tiny chute had opened it would not have added the over 0.2kg*9.81m/s worth of drag force that we apparently witnessed.

2/9/2015: NSL-34 showed a similarly low ascent rate during the first few thousand feet. This gives hope that this flight later increased its ascent and that it may have landed in eastern NC.

Mystery #2: Why did we lose the tracker?

Reported battery voltage appeared fine. I had previously run the exact configuration for >6 hours without issue. The reported on-board temperature was fine also (around 100F). The 808 camera gives off heat which kept the payload warm inside the green insulation. What caused the loss of signal?

The developer suspects a software bug and sent free a replacement.