[LeArc] WB8ELK long flight recap

Tue Apr 29 15:39:54 EDT 2008

FYI:

----- Forwarded Message ----
From: "wb8elk at aol.com" <wb8elk at aol.com>
Sent: Monday, April 28, 2008 5:30:24 PM
Subject: [Balloon_Sked] WB8ELK long duration flight recap

Long duration latex flight recap:

We launched Saturday afternoon at 3:24 pm CDT....1500 gram latex with intentional 1/16" vent hole in the nozzle. 

Details as follows:

Launch: 3:24 pm CDT (2024 UTC) - 4/26/08

Maximum altitude: 32882 meters (107,880 feet) at 0008 UTC.

Last heard signal report on Sunday 4/27/08:   8:56 am CDT (1356 UTC) by N4TXI of Madison, AL....last Hellscreiber screen image clear enough to copy the data was at 8:50 am CDT by N4MSJ of Madison, AL.

So...time aloft would be: 17h 32m.

============ ===
Sunday morning 4/27/08:
8:54 am CDT <N4TXI> in fact, I think I just lost it.
8:56 am CDT <N4TXI> in the waterfall, I just just -barely- make out the jumping rtty.  hell is no go at all
------------ --------- ------

RTTY came back to life during the night after it cold soaked at -46 deg for several hours and went goofy again shortly after heating up again after sunrise. Looks like the GPS18-LVC loses lock below 4:58 volts....The GPS did not come back to life after sunrise possibly because the battery voltage never rose back over 5 volts again.

 Float altitude bounced up and down between 97,000 feet and 104,000 feet all night. Hellscreiber mode worked just fine throughout the flight.

Last good GPS position report  - at 5:14 am CDT (1014 UTC) -  (kept sending this same data until 8:56 am) :

36 34.54N  84 56.10W 

Last good report that reported altitude (at 1011 UTC):

WB8ELK-15:/903/ 101058/101100/ 3634.20/08456. 58/017/050/ 1/04/29487. 4/4.58/-46/ 126/W 

Decoding above:  Sequence number: 903, Timestamp (GGA), Timestamp (RMC), lat,lon, ground speed = 17 knots, bearing = 050 deg, satellite lock, sats in view, altitude(29487. 4m), battery voltage (4.58 v), internal temp (-46 deg C), pressure sensor ADC count (126), W (west longitude)

============ ========= ========= ====
Flight Experiment:  short piece of 1" conduit pipe with end cap in the balloon nozzle with 1/16" vent hole drilled in the end cap.

1500 gram latex - Scientific Sales
12 ounce payload - 1.5 pound flight train weight
2.5 pounds nozzle lift at takeoff

running 6 AA L91 lithium batteries.
Power output on 10.142 MHz - 0.5 watts at 9 volts - probably down to 200 milliwatts or less at sunrise.

Estimated landing site is north of Crossville, TN in lower Kentucky just across the TN/KY border....ground speeds at 105,000 feet during the night were minimal..only a few knots, so it hovered over middle TN most of the night.

- Bill WB8ELK

I will be trying another test flight like this either this Saturday, May 3rd or the following weekend on May 10th (same as last weekend on 10.141 MHz USB)...will also be flying a 144.34 FM AFSK RTTY/CW transmitter. ...I will try to fly a crossband voice repeater on a long duration flight during Field Day weekend.

Mark Garrett, KA9SZX