August 2, 2006 E-Sonde 6 Flight Train

Jayson Barr        08/02/06

For the original notes made at the balloon hanger before launch,
    see Langmuir Lab Yellow Log Book # 20: Jayson Barr  pg. 33-37


Train Device Pictures Description
Balloon balloon and author

balloon to rope

balloon rope knot

rope to line
The factory marked 600 gram latex balloon is from Scientific Sales, Inc. (https://secure.scientificsales.com).  Its last actual measured mass was 608 grams.  Its connection to the train is first by rope and then to fishing line.  The attachement to the rope is a bowline knot on the balloon end (with some extra overhand knots for remaining length of limp rope) and a series of overhand knots that hold a loop of fishing line with plastic spring covering it in place.  Below that the line is connected to a sandbag (which will be cut right before launch).  The was rope connected to the balloon by first folding the filling end of the balloon in half longways (perpendicular to the ground), then sealed with two cable ties, then wrapped with plastic, another cable tie towards the top of the plastic, folded in half the other way around the loop of rope, then held by two more cable ties, and finally wrapped around many times with tape.  The rope was 92.5 cm in length.

The fishing line then stretches 6.39 meters to the parachute and cut down package.
Cut down package cutdown connection to balloon
cut down package
The cut down package had a mass of 468 grams with dimensions of 18cm x 12.5 cm x 8 cm.  The cut down package was nestled inside the parachute with the line running through it and then down 1.63 m to where the ropes from the detangler ring attach to the main line.
Parachute parachute

Parachute
The parachute and the detangler ring together had a mass of 294 grams.  The ropes from the parachute went down about 1 meter to the detangler new ring made by Gao Peng Lu and then another 30 cm to where they attach to the main line.  Loops were tied in the ropes to attach to the detangler ring about 29 cm from their attachment to the main line below (two loops per rope because there are four ropes each attached to the parachute at both ends.
De-Tangler Ring Detangler Ring

Detangler connection to Line

detangler ring to line
The detangler ring and the parachute together had a mass of 294 grams.  The detangler ring itself was a piece of copper wire wrapped in black duct tape.  Eight evenly spaced pices of more duct tape were put around the ring to make points of greater width.  Here, the loops in the parachute cord were cable tied to the ring, the extra cable tie length snipped off, and copious amounts of duct tape wrapped around the cable ties to keep them in place.  From there the ropes led down to be connected to the main line with the use of clamps.
Line Line 1

Line 2
From the parachute cords' connection, three pieces of connected fishing line (with lengths or 30 cm, 36 cm, and 1.95 m in order from highest to lowest) were connected down to the damper.  The connector from the first piece of this line to the second allows the line to twist freely like a swivel.
Damper Damper Conection to line

Damper connection to line

damper

Damper connection to Esonde

Esonde connection to Damper
The line above connects to the damper and more fishing line stretching down.  The damper is 1.26 m in length and the line is just slightly shorter.  This is important to keep the tension on the line and not the damper.  The line traveled down the side of the damper to its middle, was strung through a hole in the middle of the damper, and went down to the end.   Another percausion was made to make sure the tension was not on the damper: the line coming up from the Esonde was connected to line going down the middle of the damper, but the bottom of the damper was connected to the line going down its side seperately by a little loop of fishing line.  A test of putting tension above and below the damper showed this method to be effective in keeping the tension off the damper.

The line from the Esonde to the damper was 27 cm in length, attached with two clamps at both ends.
E-Sonde 6 stand and package

stand and package

stand and Esonde
The line to the Esonde was attached to two squeeze clamps that connected directly to the fishing line coming off of the Esonde.  The length from the line connection to the Esonde was about 40 cm.

The Esonde itself had a mass of 1.992 kg.

The total mass of the train came to 2.908 kg neglecting the mass of the line and rope connecting the balloon to the main line.  This plus 25% free lift (25% of the train mass) came to 3.5 kg which is equivalent to 8 lb.'s.  The mass with out the line and rope with the free lift as well as the balloon was therefore 4.2 kg, and using our handy conversion:
1 kg of lift = 68 psi at the balloon hanger

we knew that we needed 285 psi.

It was calculated that, with the pressure and temperature of that days sounding at a close altitude, the approximate circumference of the balloon should have been around 593 cm.

For more information please see the Langmuir Lab Yellow Log Book # 20: Jayson Barr  pg. 33-37