Date   

Re: Helium in a tank?

Mark Conner N9XTN
 

I think helium from virtually any industrial gas supplier, even if labeled "balloon grade", is at least 99% purity, and often balloon grade is 99.99%.  Five nines is decent for most all industrial uses and six nines is towards laboratory grade.  You can ask if you got balloon grade or industrial grade, might even say on the invoice.  At Matheson (fka Linweld here), they put stickers on the balloon grade cylinders and the industrial grade ones aren't marked, but it's been several years since I got helium from them.

The small party balloon cylinders don't seem to have a fixed purity standard.  I read once that they sometimes blend with ~20% oxygen so that people who want to make Donald Duck voices with it don't end up asphyxiating themselves.  Don't bet your life on that though.

It's possible temperature effects might have affected your positive lift.  Other errors in the overall system probably are larger than the effect of having two vs five nines helium purity, unless you're doing flights where you measure lift in a few grams instead of a few pounds. 

73 de Mark N9XTN




On Sun, Jul 19, 2020 at 7:56 PM Larry <larry.phegley@...> wrote:
My payload went up at a slower rate that I had forecasted last time and I know I just got kind of lazy and sloppy.  But even with me adding weight to the payload and not accounting for it the helium should have caused the milk jug to go neutrally buoyant with the amount of gas that I got from the burst calculator.  We ended up emptying the bottle into the balloon which should have been 19 cu ft more than required.  I am guessing the burst calculator was correct.  Is there any reason for me to doubt the amount of helium in the tank as long as I verify the pressure is correct?  Should I ask the welding supply shop about the purity of their helium?

I am trying to be more careful this time

Larry
KJ6PBS


Helium in a tank?

Larry
 

My payload went up at a slower rate that I had forecasted last time and I know I just got kind of lazy and sloppy.  But even with me adding weight to the payload and not accounting for it the helium should have caused the milk jug to go neutrally buoyant with the amount of gas that I got from the burst calculator.  We ended up emptying the bottle into the balloon which should have been 19 cu ft more than required.  I am guessing the burst calculator was correct.  Is there any reason for me to doubt the amount of helium in the tank as long as I verify the pressure is correct?  Should I ask the welding supply shop about the purity of their helium?

I am trying to be more careful this time

Larry
KJ6PBS


Superpressure balloon valve / was Re: [GPSL] K5NOT-11 WSPR Balloon Failure

Hank Riley
 

Looking at the cross section dimensioned drawing and the photograph, it's pretty certain the tetroon was filled through an internally threaded port. After removing the fill tube from the port, the calibrated pressure release valve was threaded into the same port using the  narrow, OD-threaded valve nipple, thus sealing the balloon.

This method allows for a casual (not requiring precision to reach a given equilibrium altitude) and "overfilled" (compared to a valveless flight) inflation of the tetroon.
The overfilling would of course result in a faster ascent.

So the equilibrium height would be determined by the valve release setting, not by a precisely measured amount of fill (as measured by gas volume delivered, or indirectly by the value of free lift produced at the launch site).


On Saturday, July 18, 2020, 11:44:33 PM EDT, James Ewen  wrote:

Is this valve to be used for filling, or venting?

It sounds like the intent was to allow for over fill for rapid ascent, and then release pressure at altitude. 


Re: K5NOT-11 WSPR Balloon Failure

Joe WB9SBD
 

I did that once. But the ping pong ball surface is too textured and does not make a bubble tight seal. I did a silicone ball and o ring.

Even that getting the right spring tension at these tiny tiny pressure differentials and yet tight enough to get a seal is extremely hard to do.

Joe WB9SBD

On 7/18/2020 6:05 PM, Jerry via groups.io wrote:
Below is the image from the document Steve was referring to.

Someone that flies the picos, does a simple valve sound like something that might work?  It might make attaching the payload difficult.





Jerry Gable
Balloon Flight Prediction tools
http://www.s3research.com


On Saturday, July 18, 2020, 12:01:33 PM MST, Steve G8KHW / AJ4XE <steve@...> wrote:


Looks like that link does not work - search for the paper "Characteristics and Performance of Three Low-Cost Superpressure Balloon (Tetroon) Systems "

    Steve

On 18/07/2020 19:40, Steve G8KHW / AJ4XE wrote:

See the ping-pong valve described here:

    https://tinyurl.com/y5ukveyb

see fig 4

    Steve


On 18/07/2020 18:53, Jerry via groups.io wrote:
It seems like over inflation is a common problem.  Could we come up with a simple (and light) pressure releif valve that is inseted in the fill tube?  Maybe something that could be 3d printed.  You could also use overfill for a faster initial climb.  It might save a lot of balloons. 

Jerry


On Sat, Jul 18, 2020 at 10:31 AM, Michael
<mw@...> wrote:
Hi All,

I plotted the ascent and unexpected descent of the GPSL K5NOT-11 WSPR balloon I sent up. It was a WSPR Skytracker and SBS-13 balloon of which I had trouble sealing - the sealing unit recommended was not available and an equivalent unit melted the neck right off. The equivalent unit was likely defective and too hot. I had eventually sealed the neck and folded it up like we do with latex balloons. I felt it was probably OK to fly. However, after a short time at 43,000 ft float level the balloon came back down. I assumed the premature descent to be caused from where I sealed it.

However, something about the descent did not make sense. If the leak was at the bottom - at the seal, I would expect the balloon to descend some portion and then somewhat stabilize at a fair altitude as the helium would want to stay at the top of the envelope and not flow down and out at the filling neck. Instead it descended all the way on a very linear line. I now highly suspect the leak actually was a pinhole or larger that developed in flight at or near the top of the envelope as a very under-inflated envelope with positive buoyancy took the payload aloft. The balloon was filled to 7 grams of positive lift.

According to the ascent table provided by Scientific Balloons - who makes the SBS-13, 5-8gr of lift is the sweet spot. I measured the lift in several different ways and confirmed 7 gr lift. However, based on the table also provided by Scientific Balloons, the 7gr of lift should result in less than 1.3 meters of ascent rate. When I calculated the time from launch to float I came up with 1.77 meters / second ascent rate which does not agree with the 1.3 meters targeted, but rather reflects over 10 gr but less than 12 gr of free lift which is too much.

What I learned from premature descent of the K5NOT-11 balloon via the NTSB (North Texas Squirrely Balloon) analysis:
  • Free lift was most likely the culprit causing an over pressure envelope failure at the top of the envelope and not caused by a bad seal at the neck. The free lift was measured with a 0.1gr repeatable accuracy, but does not match up with the tables provided by Scientific Balloons, so an error / discrepancy / calibration issue crept in here in some manner.
  • Even though the sealer was a bear, it eventually sealed - and folding and taping probably was good as extra insurance.
  • When you seal one of these balloons, try sealing on the very end of the neck first to prove the seal process before sealing where you actually want the seal.
  • Science can be fun until your hope of achievement is overwhelmed by the realization of complete failure.
--Michael


Virus-free. www.avg.com


Re: K5NOT-11 WSPR Balloon Failure

Steve G8KHW / AJ4XE
 

The latter (rapid ascent and gas release at the desired altitude) . 

Another idea in the paper is a lift balloon - where the superpressure balloon is filled to just the correct amount on the ground and hauled up a latex balloon and released at the correct altitude.

    Steve G8KHW/AJ4XE

On 19/07/2020 04:44, James Ewen VE6SRV wrote:
Is this valve to be used for filling, or venting?

It sounds like the intent was to allow for over fill for rapid ascent, and then release pressure at altitude. 

James 
VE6SRV 

--
James
VE6SRV

Virus-free. www.avg.com


Re: K5NOT-11 WSPR Balloon Failure

James Ewen VE6SRV
 

Is this valve to be used for filling, or venting?

It sounds like the intent was to allow for over fill for rapid ascent, and then release pressure at altitude. 

James 
VE6SRV 

--
James
VE6SRV


Re: K5NOT-11 WSPR Balloon Failure

Jeff Ducklow
 

Seems like a elegant design solution, but not having pico flight experience, I’m wondering about the mass penalty for pico flight. 

 I'm estimating this value design to weigh between 7 and 10 grams.  I weighed out a  ping-pong ball, a lightweight spring, and a toothpick as a rod and came up with 3.1 grams.  I guessing that a printed nozzle would be at least 4  to 7 grams if not more.

I’d be interested in hearing from those with pico flight experience on practicality of adding the mass of a value, and if there are other issues to might bring?



On Jul 18, 2020, at 6:05 PM, Jerry via groups.io <jerrygable@...> wrote:

Below is the image from the document Steve was referring to.

Someone that flies the picos, does a simple valve sound like something that might work?  It might make attaching the payload difficult.


<1595113389798blob.jpg>


Jerry Gable
Balloon Flight Prediction tools
http://www.s3research.com


On Saturday, July 18, 2020, 12:01:33 PM MST, Steve G8KHW / AJ4XE <steve@...> wrote:


Looks like that link does not work - search for the paper "Characteristics and Performance of Three Low-Cost Superpressure Balloon (Tetroon) Systems "

    Steve

On 18/07/2020 19:40, Steve G8KHW / AJ4XE wrote:

See the ping-pong valve described here:

    https://tinyurl.com/y5ukveyb

see fig 4

    Steve


On 18/07/2020 18:53, Jerry via groups.io wrote:
It seems like over inflation is a common problem.  Could we come up with a simple (and light) pressure releif valve that is inseted in the fill tube?  Maybe something that could be 3d printed.  You could also use overfill for a faster initial climb.  It might save a lot of balloons. 

Jerry


On Sat, Jul 18, 2020 at 10:31 AM, Michael
<mw@...> wrote:
Hi All,

I plotted the ascent and unexpected descent of the GPSL K5NOT-11 WSPR balloon I sent up. It was a WSPR Skytracker and SBS-13 balloon of which I had trouble sealing - the sealing unit recommended was not available and an equivalent unit melted the neck right off. The equivalent unit was likely defective and too hot. I had eventually sealed the neck and folded it up like we do with latex balloons. I felt it was probably OK to fly. However, after a short time at 43,000 ft float level the balloon came back down. I assumed the premature descent to be caused from where I sealed it.

However, something about the descent did not make sense. If the leak was at the bottom - at the seal, I would expect the balloon to descend some portion and then somewhat stabilize at a fair altitude as the helium would want to stay at the top of the envelope and not flow down and out at the filling neck. Instead it descended all the way on a very linear line. I now highly suspect the leak actually was a pinhole or larger that developed in flight at or near the top of the envelope as a very under-inflated envelope with positive buoyancy took the payload aloft. The balloon was filled to 7 grams of positive lift.

According to the ascent table provided by Scientific Balloons - who makes the SBS-13, 5-8gr of lift is the sweet spot. I measured the lift in several different ways and confirmed 7 gr lift. However, based on the table also provided by Scientific Balloons, the 7gr of lift should result in less than 1.3 meters of ascent rate. When I calculated the time from launch to float I came up with 1.77 meters / second ascent rate which does not agree with the 1.3 meters targeted, but rather reflects over 10 gr but less than 12 gr of free lift which is too much.

What I learned from premature descent of the K5NOT-11 balloon via the NTSB (North Texas Squirrely Balloon) analysis:
  • Free lift was most likely the culprit causing an over pressure envelope failure at the top of the envelope and not caused by a bad seal at the neck. The free lift was measured with a 0.1gr repeatable accuracy, but does not match up with the tables provided by Scientific Balloons, so an error / discrepancy / calibration issue crept in here in some manner.
  • Even though the sealer was a bear, it eventually sealed - and folding and taping probably was good as extra insurance.
  • When you seal one of these balloons, try sealing on the very end of the neck first to prove the seal process before sealing where you actually want the seal.
  • Science can be fun until your hope of achievement is overwhelmed by the realization of complete failure.
--Michael


Virus-free. www.avg.com
<1595113389798blob.jpg>


Re: K5NOT-11 WSPR Balloon Failure

Jerry
 

Below is the image from the document Steve was referring to.

Someone that flies the picos, does a simple valve sound like something that might work?  It might make attaching the payload difficult.


Inline image


Jerry Gable
Balloon Flight Prediction tools
http://www.s3research.com


On Saturday, July 18, 2020, 12:01:33 PM MST, Steve G8KHW / AJ4XE <steve@...> wrote:


Looks like that link does not work - search for the paper "Characteristics and Performance of Three Low-Cost Superpressure Balloon (Tetroon) Systems "

    Steve

On 18/07/2020 19:40, Steve G8KHW / AJ4XE wrote:

See the ping-pong valve described here:

    https://tinyurl.com/y5ukveyb

see fig 4

    Steve


On 18/07/2020 18:53, Jerry via groups.io wrote:
It seems like over inflation is a common problem.  Could we come up with a simple (and light) pressure releif valve that is inseted in the fill tube?  Maybe something that could be 3d printed.  You could also use overfill for a faster initial climb.  It might save a lot of balloons. 

Jerry


On Sat, Jul 18, 2020 at 10:31 AM, Michael
<mw@...> wrote:
Hi All,

I plotted the ascent and unexpected descent of the GPSL K5NOT-11 WSPR balloon I sent up. It was a WSPR Skytracker and SBS-13 balloon of which I had trouble sealing - the sealing unit recommended was not available and an equivalent unit melted the neck right off. The equivalent unit was likely defective and too hot. I had eventually sealed the neck and folded it up like we do with latex balloons. I felt it was probably OK to fly. However, after a short time at 43,000 ft float level the balloon came back down. I assumed the premature descent to be caused from where I sealed it.

However, something about the descent did not make sense. If the leak was at the bottom - at the seal, I would expect the balloon to descend some portion and then somewhat stabilize at a fair altitude as the helium would want to stay at the top of the envelope and not flow down and out at the filling neck. Instead it descended all the way on a very linear line. I now highly suspect the leak actually was a pinhole or larger that developed in flight at or near the top of the envelope as a very under-inflated envelope with positive buoyancy took the payload aloft. The balloon was filled to 7 grams of positive lift.

According to the ascent table provided by Scientific Balloons - who makes the SBS-13, 5-8gr of lift is the sweet spot. I measured the lift in several different ways and confirmed 7 gr lift. However, based on the table also provided by Scientific Balloons, the 7gr of lift should result in less than 1.3 meters of ascent rate. When I calculated the time from launch to float I came up with 1.77 meters / second ascent rate which does not agree with the 1.3 meters targeted, but rather reflects over 10 gr but less than 12 gr of free lift which is too much.

What I learned from premature descent of the K5NOT-11 balloon via the NTSB (North Texas Squirrely Balloon) analysis:
  • Free lift was most likely the culprit causing an over pressure envelope failure at the top of the envelope and not caused by a bad seal at the neck. The free lift was measured with a 0.1gr repeatable accuracy, but does not match up with the tables provided by Scientific Balloons, so an error / discrepancy / calibration issue crept in here in some manner.
  • Even though the sealer was a bear, it eventually sealed - and folding and taping probably was good as extra insurance.
  • When you seal one of these balloons, try sealing on the very end of the neck first to prove the seal process before sealing where you actually want the seal.
  • Science can be fun until your hope of achievement is overwhelmed by the realization of complete failure.
--Michael


Virus-free. www.avg.com


Update on GPSL videos

Mark Conner N9XTN
 

We're in the final stages of having the videos ready on the "GPSL Live" channel at YouTube.  Some are available now, and more will be coming soon.  Thanks to Jim Emmert for editing the Zoom videos into neat packages.


We will also be making the slides available, stand by for those details.

73 de Mark N9XTN


Re: K5NOT-11 WSPR Balloon Failure

Steve G8KHW / AJ4XE
 

Looks like that link does not work - search for the paper "Characteristics and Performance of Three Low-Cost Superpressure Balloon (Tetroon) Systems "

    Steve

On 18/07/2020 19:40, Steve G8KHW / AJ4XE wrote:

See the ping-pong valve described here:

    https://tinyurl.com/y5ukveyb

see fig 4

    Steve


On 18/07/2020 18:53, Jerry via groups.io wrote:
It seems like over inflation is a common problem.  Could we come up with a simple (and light) pressure releif valve that is inseted in the fill tube?  Maybe something that could be 3d printed.  You could also use overfill for a faster initial climb.  It might save a lot of balloons. 

Jerry


On Sat, Jul 18, 2020 at 10:31 AM, Michael
<mw@...> wrote:
Hi All,

I plotted the ascent and unexpected descent of the GPSL K5NOT-11 WSPR balloon I sent up. It was a WSPR Skytracker and SBS-13 balloon of which I had trouble sealing - the sealing unit recommended was not available and an equivalent unit melted the neck right off. The equivalent unit was likely defective and too hot. I had eventually sealed the neck and folded it up like we do with latex balloons. I felt it was probably OK to fly. However, after a short time at 43,000 ft float level the balloon came back down. I assumed the premature descent to be caused from where I sealed it.

However, something about the descent did not make sense. If the leak was at the bottom - at the seal, I would expect the balloon to descend some portion and then somewhat stabilize at a fair altitude as the helium would want to stay at the top of the envelope and not flow down and out at the filling neck. Instead it descended all the way on a very linear line. I now highly suspect the leak actually was a pinhole or larger that developed in flight at or near the top of the envelope as a very under-inflated envelope with positive buoyancy took the payload aloft. The balloon was filled to 7 grams of positive lift.

According to the ascent table provided by Scientific Balloons - who makes the SBS-13, 5-8gr of lift is the sweet spot. I measured the lift in several different ways and confirmed 7 gr lift. However, based on the table also provided by Scientific Balloons, the 7gr of lift should result in less than 1.3 meters of ascent rate. When I calculated the time from launch to float I came up with 1.77 meters / second ascent rate which does not agree with the 1.3 meters targeted, but rather reflects over 10 gr but less than 12 gr of free lift which is too much.

What I learned from premature descent of the K5NOT-11 balloon via the NTSB (North Texas Squirrely Balloon) analysis:
  • Free lift was most likely the culprit causing an over pressure envelope failure at the top of the envelope and not caused by a bad seal at the neck. The free lift was measured with a 0.1gr repeatable accuracy, but does not match up with the tables provided by Scientific Balloons, so an error / discrepancy / calibration issue crept in here in some manner.
  • Even though the sealer was a bear, it eventually sealed - and folding and taping probably was good as extra insurance.
  • When you seal one of these balloons, try sealing on the very end of the neck first to prove the seal process before sealing where you actually want the seal.
  • Science can be fun until your hope of achievement is overwhelmed by the realization of complete failure.
--Michael


Virus-free. www.avg.com


Re: K5NOT-11 WSPR Balloon Failure

Steve G8KHW / AJ4XE
 

See the ping-pong valve described here:

    https://tinyurl.com/y5ukveyb

see fig 4

    Steve


On 18/07/2020 18:53, Jerry via groups.io wrote:
It seems like over inflation is a common problem.  Could we come up with a simple (and light) pressure releif valve that is inseted in the fill tube?  Maybe something that could be 3d printed.  You could also use overfill for a faster initial climb.  It might save a lot of balloons. 

Jerry


On Sat, Jul 18, 2020 at 10:31 AM, Michael
<mw@...> wrote:
Hi All,

I plotted the ascent and unexpected descent of the GPSL K5NOT-11 WSPR balloon I sent up. It was a WSPR Skytracker and SBS-13 balloon of which I had trouble sealing - the sealing unit recommended was not available and an equivalent unit melted the neck right off. The equivalent unit was likely defective and too hot. I had eventually sealed the neck and folded it up like we do with latex balloons. I felt it was probably OK to fly. However, after a short time at 43,000 ft float level the balloon came back down. I assumed the premature descent to be caused from where I sealed it.

However, something about the descent did not make sense. If the leak was at the bottom - at the seal, I would expect the balloon to descend some portion and then somewhat stabilize at a fair altitude as the helium would want to stay at the top of the envelope and not flow down and out at the filling neck. Instead it descended all the way on a very linear line. I now highly suspect the leak actually was a pinhole or larger that developed in flight at or near the top of the envelope as a very under-inflated envelope with positive buoyancy took the payload aloft. The balloon was filled to 7 grams of positive lift.

According to the ascent table provided by Scientific Balloons - who makes the SBS-13, 5-8gr of lift is the sweet spot. I measured the lift in several different ways and confirmed 7 gr lift. However, based on the table also provided by Scientific Balloons, the 7gr of lift should result in less than 1.3 meters of ascent rate. When I calculated the time from launch to float I came up with 1.77 meters / second ascent rate which does not agree with the 1.3 meters targeted, but rather reflects over 10 gr but less than 12 gr of free lift which is too much.

What I learned from premature descent of the K5NOT-11 balloon via the NTSB (North Texas Squirrely Balloon) analysis:
  • Free lift was most likely the culprit causing an over pressure envelope failure at the top of the envelope and not caused by a bad seal at the neck. The free lift was measured with a 0.1gr repeatable accuracy, but does not match up with the tables provided by Scientific Balloons, so an error / discrepancy / calibration issue crept in here in some manner.
  • Even though the sealer was a bear, it eventually sealed - and folding and taping probably was good as extra insurance.
  • When you seal one of these balloons, try sealing on the very end of the neck first to prove the seal process before sealing where you actually want the seal.
  • Science can be fun until your hope of achievement is overwhelmed by the realization of complete failure.
--Michael


Virus-free. www.avg.com


Re: K5NOT-11 WSPR Balloon Failure

Jerry
 

It seems like over inflation is a common problem.  Could we come up with a simple (and light) pressure releif valve that is inseted in the fill tube?  Maybe something that could be 3d printed.  You could also use overfill for a faster initial climb.  It might save a lot of balloons. 

Jerry


On Sat, Jul 18, 2020 at 10:31 AM, Michael
<mw@...> wrote:
Hi All,

I plotted the ascent and unexpected descent of the GPSL K5NOT-11 WSPR balloon I sent up. It was a WSPR Skytracker and SBS-13 balloon of which I had trouble sealing - the sealing unit recommended was not available and an equivalent unit melted the neck right off. The equivalent unit was likely defective and too hot. I had eventually sealed the neck and folded it up like we do with latex balloons. I felt it was probably OK to fly. However, after a short time at 43,000 ft float level the balloon came back down. I assumed the premature descent to be caused from where I sealed it.

However, something about the descent did not make sense. If the leak was at the bottom - at the seal, I would expect the balloon to descend some portion and then somewhat stabilize at a fair altitude as the helium would want to stay at the top of the envelope and not flow down and out at the filling neck. Instead it descended all the way on a very linear line. I now highly suspect the leak actually was a pinhole or larger that developed in flight at or near the top of the envelope as a very under-inflated envelope with positive buoyancy took the payload aloft. The balloon was filled to 7 grams of positive lift.

According to the ascent table provided by Scientific Balloons - who makes the SBS-13, 5-8gr of lift is the sweet spot. I measured the lift in several different ways and confirmed 7 gr lift. However, based on the table also provided by Scientific Balloons, the 7gr of lift should result in less than 1.3 meters of ascent rate. When I calculated the time from launch to float I came up with 1.77 meters / second ascent rate which does not agree with the 1.3 meters targeted, but rather reflects over 10 gr but less than 12 gr of free lift which is too much.

What I learned from premature descent of the K5NOT-11 balloon via the NTSB (North Texas Squirrely Balloon) analysis:
  • Free lift was most likely the culprit causing an over pressure envelope failure at the top of the envelope and not caused by a bad seal at the neck. The free lift was measured with a 0.1gr repeatable accuracy, but does not match up with the tables provided by Scientific Balloons, so an error / discrepancy / calibration issue crept in here in some manner.
  • Even though the sealer was a bear, it eventually sealed - and folding and taping probably was good as extra insurance.
  • When you seal one of these balloons, try sealing on the very end of the neck first to prove the seal process before sealing where you actually want the seal.
  • Science can be fun until your hope of achievement is overwhelmed by the realization of complete failure.
--Michael


K5NOT-11 WSPR Balloon Failure

Michael
 

Hi All,

I plotted the ascent and unexpected descent of the GPSL K5NOT-11 WSPR balloon I sent up. It was a WSPR Skytracker and SBS-13 balloon of which I had trouble sealing - the sealing unit recommended was not available and an equivalent unit melted the neck right off. The equivalent unit was likely defective and too hot. I had eventually sealed the neck and folded it up like we do with latex balloons. I felt it was probably OK to fly. However, after a short time at 43,000 ft float level the balloon came back down. I assumed the premature descent to be caused from where I sealed it.

However, something about the descent did not make sense. If the leak was at the bottom - at the seal, I would expect the balloon to descend some portion and then somewhat stabilize at a fair altitude as the helium would want to stay at the top of the envelope and not flow down and out at the filling neck. Instead it descended all the way on a very linear line. I now highly suspect the leak actually was a pinhole or larger that developed in flight at or near the top of the envelope as a very under-inflated envelope with positive buoyancy took the payload aloft. The balloon was filled to 7 grams of positive lift.

According to the ascent table provided by Scientific Balloons - who makes the SBS-13, 5-8gr of lift is the sweet spot. I measured the lift in several different ways and confirmed 7 gr lift. However, based on the table also provided by Scientific Balloons, the 7gr of lift should result in less than 1.3 meters of ascent rate. When I calculated the time from launch to float I came up with 1.77 meters / second ascent rate which does not agree with the 1.3 meters targeted, but rather reflects over 10 gr but less than 12 gr of free lift which is too much.

What I learned from premature descent of the K5NOT-11 balloon via the NTSB (North Texas Squirrely Balloon) analysis:
  • Free lift was most likely the culprit causing an over pressure envelope failure at the top of the envelope and not caused by a bad seal at the neck. The free lift was measured with a 0.1gr repeatable accuracy, but does not match up with the tables provided by Scientific Balloons, so an error / discrepancy / calibration issue crept in here in some manner.
  • Even though the sealer was a bear, it eventually sealed - and folding and taping probably was good as extra insurance.
  • When you seal one of these balloons, try sealing on the very end of the neck first to prove the seal process before sealing where you actually want the seal.
  • Science can be fun until your hope of achievement is overwhelmed by the realization of complete failure.
--Michael


Re: KQ6RS1 WSPR Buoy has been deployed in the Pacific Ocean SW of San Diego

Bill Brown
 

Yep it is right....ocean currents are slow where it is currently located.

- Bill WB8ELK


-----Original Message-----
From: greg@... <greg@...>
To: GPSL@groups.io
Sent: Fri, Jul 17, 2020 5:37 pm
Subject: Re: [GPSL] KQ6RS1 WSPR Buoy has been deployed in the Pacific Ocean SW of San Diego

It doesn't appear to be moving much at all, can that be right?

Greg K7RKT


Re: KQ6RS1 WSPR Buoy has been deployed in the Pacific Ocean SW of San Diego

greg@bigredbee.com
 

It doesn't appear to be moving much at all, can that be right?

Greg K7RKT


Re: GPSL Pico balloons status update KM6BWB10 back in CA

Ryan Butler
 

It's here!  Moving at a good clip too!


On Fri, Jul 17, 2020 at 2:50 PM Harry M <hhm_74115@...> wrote:
KM6BWB-10 will be over Iowa shortly.


Re: GPSL Pico balloons status update KM6BWB10 back in CA

Harry M
 

KM6BWB-10 will be over Iowa shortly.


Re: GPSL Pico balloons status update KM6BWB10 back in CA

Bill Brown
 

Floyd,

  You can see all of the balloons currently flying in the World at:   tracker.habhub.org    or enter the GPSL callsigns of the balloons still flying on APRS.FI separated by commas.  KM6BWB-10 and KC7VQR-11 are still flying.



- Bill WB8ELK




-----Original Message-----
From: Floyd Rodgers <kc5qbc@...>
To: GPSL@groups.io
Sent: Thu, Jul 16, 2020 7:52 pm
Subject: Re: [GPSL] GPSL Pico balloons status update KM6BWB10 back in CA

What’s the trick or how can I find all the flyers on aprs or what ever tracking method. Dummies guide to balloon tracking....

Floyd KC5QBC

On Jul 16, 2020, at 7:35 PM, Bill Brown via groups.io <wb8elk@...> wrote:


UPDATE:

KM6BWB-10 returned to California today after a big loop into Mexico and out into the Pacific near Baja. Still flying high !!!

- Bill WB8ELK


-----Original Message-----
From: Bill Brown via groups.io <wb8elk@...>
To: gpsl@groups.io <gpsl@groups.io>
Sent: Thu, Jul 16, 2020 11:06 am
Subject: [GPSL] GPSL Pico balloons status updates

Out of the 10 Pico Balloons that were launched last Saturday for GPSL (2 on Sunday), one is currently being received as it flies over Bulgaria (KC7VQR-11) and two more may still be flying but out of range of APRS ground stations. Here's the status of all of the balloons so far:

Still flying or potentially still flying:
KC7VQR-11 (APRS Skytracker with SBS-13 balloon) - Currently flying over Bulgaria. 7 grams of free lift with helium.
KM6BWB-10 (APRS Skytracker with two silver foil balloons - Last heard in Mexico, if it is still flying it should show up back in CA/AZ on 7/18 @ 2200z.
KK6UUQ-7 (APRS SKytracker with single foil balloon - Launched, burst, recovered from a field then flown again within a few hours and last heard SW of New Orleans. Predicted to show up 7/18 @ 1200z in east TX

On the ground:
VA5BNC-15 (APRS custom built by Bruce VE5BNC - 25 grams on a single foil balloon) - Landed in east GA, then took off again the next morning and landed near Orangeburg SC.
WB8ELK-10 (APRS Skytracker on a single silver foil balloon) - Hit bad storms along NC coast not far from Kitty Hawk and looks like it splashed down a half mile from shore.
KM4ZIA-2 (WSPR Skytracker on SBS-13 balloon) - Hit bad storms off the coast of NC and probably splashed down in the Atlantic.
KM4BUN-1 (WSPR Skytracker on SBS-13 balloon) - Hit bad storms off the coast of NC and probably splashed down in the Atlantic.
K5NOT-11 (WSPR Skytracker on SBS-13 balloon) - Had trouble heat sealing the filling port so likely caused leak after 20 minutes of float time. Landed in central TX.
W5HRH-15 (WSPR board on SBS-13 balloon) -  10 grams of free lift, anything over 8 grams has more risk. if it works it will work very well but increased risk of leaking as it achieves float altitude. It burst and came down in South Texas. I did have one work great with 11 grams of free lift but that's the upper limit. The most recent successes I have observed have had between 6.5 and 7.5 grams free lift.

Not Sure if still flying:
K7HAK-11 (APRS Skytracker with two silver foil balloons) - Likely landed in SC where there were a lot of storms. Didn't show up over Newfoundland per prediction but may still be aloft. If it doesn't show up in Europe within two days from now then it probably landed in SC.

GPSL balloons launched on Sunday:
Also W7EEU-11 launched an APRS Skytracker on a single silver foil balloon on Sunday since he couldn't launch on Saturday during our big event. It had a wild roller coaster ride after picking up some icing but finally reached a stable float on the second day. It was heading into northern Canada and may show up again in a few days in Europe if it is still flying.
K6STS launched a WSPR payload on an SBS-13 on Sunday as part of GPSL but it came down shortly about 2 miles from his house. He has recovered it and will fly again soon.

- Bill WB8ELK





Re: GPSL Pico balloons status update KM6BWB10 back in CA

Floyd Rodgers
 

What’s the trick or how can I find all the flyers on aprs or what ever tracking method. Dummies guide to balloon tracking....

Floyd KC5QBC

On Jul 16, 2020, at 7:35 PM, Bill Brown via groups.io <wb8elk@...> wrote:


UPDATE:

KM6BWB-10 returned to California today after a big loop into Mexico and out into the Pacific near Baja. Still flying high !!!

- Bill WB8ELK


-----Original Message-----
From: Bill Brown via groups.io <wb8elk@...>
To: gpsl@groups.io <gpsl@groups.io>
Sent: Thu, Jul 16, 2020 11:06 am
Subject: [GPSL] GPSL Pico balloons status updates

Out of the 10 Pico Balloons that were launched last Saturday for GPSL (2 on Sunday), one is currently being received as it flies over Bulgaria (KC7VQR-11) and two more may still be flying but out of range of APRS ground stations. Here's the status of all of the balloons so far:

Still flying or potentially still flying:
KC7VQR-11 (APRS Skytracker with SBS-13 balloon) - Currently flying over Bulgaria. 7 grams of free lift with helium.
KM6BWB-10 (APRS Skytracker with two silver foil balloons - Last heard in Mexico, if it is still flying it should show up back in CA/AZ on 7/18 @ 2200z.
KK6UUQ-7 (APRS SKytracker with single foil balloon - Launched, burst, recovered from a field then flown again within a few hours and last heard SW of New Orleans. Predicted to show up 7/18 @ 1200z in east TX

On the ground:
VA5BNC-15 (APRS custom built by Bruce VE5BNC - 25 grams on a single foil balloon) - Landed in east GA, then took off again the next morning and landed near Orangeburg SC.
WB8ELK-10 (APRS Skytracker on a single silver foil balloon) - Hit bad storms along NC coast not far from Kitty Hawk and looks like it splashed down a half mile from shore.
KM4ZIA-2 (WSPR Skytracker on SBS-13 balloon) - Hit bad storms off the coast of NC and probably splashed down in the Atlantic.
KM4BUN-1 (WSPR Skytracker on SBS-13 balloon) - Hit bad storms off the coast of NC and probably splashed down in the Atlantic.
K5NOT-11 (WSPR Skytracker on SBS-13 balloon) - Had trouble heat sealing the filling port so likely caused leak after 20 minutes of float time. Landed in central TX.
W5HRH-15 (WSPR board on SBS-13 balloon) -  10 grams of free lift, anything over 8 grams has more risk. if it works it will work very well but increased risk of leaking as it achieves float altitude. It burst and came down in South Texas. I did have one work great with 11 grams of free lift but that's the upper limit. The most recent successes I have observed have had between 6.5 and 7.5 grams free lift.

Not Sure if still flying:
K7HAK-11 (APRS Skytracker with two silver foil balloons) - Likely landed in SC where there were a lot of storms. Didn't show up over Newfoundland per prediction but may still be aloft. If it doesn't show up in Europe within two days from now then it probably landed in SC.

GPSL balloons launched on Sunday:
Also W7EEU-11 launched an APRS Skytracker on a single silver foil balloon on Sunday since he couldn't launch on Saturday during our big event. It had a wild roller coaster ride after picking up some icing but finally reached a stable float on the second day. It was heading into northern Canada and may show up again in a few days in Europe if it is still flying.
K6STS launched a WSPR payload on an SBS-13 on Sunday as part of GPSL but it came down shortly about 2 miles from his house. He has recovered it and will fly again soon.

- Bill WB8ELK





Re: GPSL Pico balloons status update KM6BWB10 back in CA

Bill Brown
 


UPDATE:

KM6BWB-10 returned to California today after a big loop into Mexico and out into the Pacific near Baja. Still flying high !!!

- Bill WB8ELK


-----Original Message-----
From: Bill Brown via groups.io <wb8elk@...>
To: gpsl@groups.io <gpsl@groups.io>
Sent: Thu, Jul 16, 2020 11:06 am
Subject: [GPSL] GPSL Pico balloons status updates

Out of the 10 Pico Balloons that were launched last Saturday for GPSL (2 on Sunday), one is currently being received as it flies over Bulgaria (KC7VQR-11) and two more may still be flying but out of range of APRS ground stations. Here's the status of all of the balloons so far:

Still flying or potentially still flying:
KC7VQR-11 (APRS Skytracker with SBS-13 balloon) - Currently flying over Bulgaria. 7 grams of free lift with helium.
KM6BWB-10 (APRS Skytracker with two silver foil balloons - Last heard in Mexico, if it is still flying it should show up back in CA/AZ on 7/18 @ 2200z.
KK6UUQ-7 (APRS SKytracker with single foil balloon - Launched, burst, recovered from a field then flown again within a few hours and last heard SW of New Orleans. Predicted to show up 7/18 @ 1200z in east TX

On the ground:
VA5BNC-15 (APRS custom built by Bruce VE5BNC - 25 grams on a single foil balloon) - Landed in east GA, then took off again the next morning and landed near Orangeburg SC.
WB8ELK-10 (APRS Skytracker on a single silver foil balloon) - Hit bad storms along NC coast not far from Kitty Hawk and looks like it splashed down a half mile from shore.
KM4ZIA-2 (WSPR Skytracker on SBS-13 balloon) - Hit bad storms off the coast of NC and probably splashed down in the Atlantic.
KM4BUN-1 (WSPR Skytracker on SBS-13 balloon) - Hit bad storms off the coast of NC and probably splashed down in the Atlantic.
K5NOT-11 (WSPR Skytracker on SBS-13 balloon) - Had trouble heat sealing the filling port so likely caused leak after 20 minutes of float time. Landed in central TX.
W5HRH-15 (WSPR board on SBS-13 balloon) -  10 grams of free lift, anything over 8 grams has more risk. if it works it will work very well but increased risk of leaking as it achieves float altitude. It burst and came down in South Texas. I did have one work great with 11 grams of free lift but that's the upper limit. The most recent successes I have observed have had between 6.5 and 7.5 grams free lift.

Not Sure if still flying:
K7HAK-11 (APRS Skytracker with two silver foil balloons) - Likely landed in SC where there were a lot of storms. Didn't show up over Newfoundland per prediction but may still be aloft. If it doesn't show up in Europe within two days from now then it probably landed in SC.

GPSL balloons launched on Sunday:
Also W7EEU-11 launched an APRS Skytracker on a single silver foil balloon on Sunday since he couldn't launch on Saturday during our big event. It had a wild roller coaster ride after picking up some icing but finally reached a stable float on the second day. It was heading into northern Canada and may show up again in a few days in Europe if it is still flying.
K6STS launched a WSPR payload on an SBS-13 on Sunday as part of GPSL but it came down shortly about 2 miles from his house. He has recovered it and will fly again soon.

- Bill WB8ELK




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