HAPB-4 – Propeller Voyage

HAPB-4 was launched 08/31/2008 at 6:34 am and recovered ~3 hours later. Maximum recorded altitude was 106,384 feet.

The sky was extemely hazy this day but the objective of capturing sunrise was accomplished. Enjoy the Images.

I am still working on the videos. Will post them soon.
KML file of flight path.

Dr. Thomas Talley and Paul Hubner
 

I
started editing my other videos when I noticed the sound wave pattern
of the still camera as it was taking pictures and decided I had to post
this tonight. If you look at the sound wave you will notice the it
tapers off as the balloon increases in altitude. I noticed this from my
last flight when I was editting the videos but I had not really looked
at the waveform until tonight. To me this is really cool because it
shows how sound travels as you approach the vacuum of space.

Sound Wave


MultiProcessor
Flight Computer (MPFC)

HAPB-4
uses Parallax’s SPIN Stamp which contains 8 micro processors known as
COGs. Each COG can operate independently or in a cooperative
environment, leaving me with an unlimited number of ways to use the
micro-processor. I also like the fact that it is in the Stamp format.
The Spin Stamp module is not intended to be a direct drop-in
replacement for any BASIC Stamp module and there are some important
points to consider before purchasing the Spin Stamp but it can be a
less intimidating method of moving to the Propeller.

I
kept the basic functionality of HAPB-3 with a few exceptions. I have
pulled the temperature probes since my APRS unit already has that
function. I am also replacing the 32K EEPROM with Parallax’s Memory
Stick Datalogger. Finally, I removed the CRDR reset, SFC Satellite
Acquired indicator, and the SFC. It sounds like a lot of chances but
its not. The functionality will be incorporated into the SPIN Stamp so
I do not need the second processor and associated supporting hardware.

Up
until now the propeller was executing code in serial fashion much like
the STAMP until I gave the procedures there own memory stack. You can
see where the power of the propeller comes into play once you start
using multiple COGs running parallel processes. You can run out of COGs
very easily and now I understand why people would like to see
additional COGs built into the chip. I am using all 8 COGs for this
flight. If I need additional parallel processes then I will switch the
External Signaling processes back to COG 0 and remove the Debug
procedure but for now I will leave it as is because I can be COG-HAPPY
until I really need them.

COG 0 – Main program space
COG 1 – LCD operations
COG 2 – Debug operation
COG 3 – GPS operations
COG 4 – GPS Serial operations
COG 5 – USB Drive
COG 6 – USB Serial operations
COG 7 – External Signalling

This
flight will be recording GGA data every 4 seconds providing over 3000
data points over a 3 hour period producing a file size of ~300.00KB. 
 I should be able to get a better idea of maximum altitude this
flight.  The Coolpix is setup to take a picture every 15 seconds which
should result in over 600 images @ 3264×2448.  The original video
recorder will record for over 3 hours and I picked up a 4GB SD card for
the HD video recorder that will allow the flight to be recorded for 2
hours 19 minutes @ 1280 x 720 Pixels (H.264) up to 30 fps.  The video
recorders are setup at opposite sides of the capsule to increase my
chances of capturing sunrise. I set the external signal lights to flash
at 40 pulses per minute below 60,000 feet in accordance with FAA rules
even though I am flying exempt.

SPIN Code – HAPB-4.SPIN
JPEG/BMP versions
of the schematic and layout.

ExpressPCB versions of the schematic and layout.


Telemetry System


I am using the
same telemetry system


from HAPB-3 with no modifications. I have plans of replacing this unit
with own using the propeller but that is for a later flight and for a
joint project I am working on with my friend Paul Hubner and his PNAV project. For now I will continue to use the Opentracker. It has proven to be a stable and reliable system.

System Testing (In-Progress)

I
ran a series of tests while going back and forward to work with the GPS
recording data every 4 seconds and the results looked good. For that
series of test I was using a light toggling on and off to emulate the
camera operations and did not have the external lights connected.

After
integrating all systems additional tests showed that the external
lights were not working properly.  I had written the procedures in a
series fashion which resulted in the altitude values toggling between 0
and the actual value.  Adding a temporary variable that could be set to
zero and manipulated with each cycle solved the problem.

Assembled
the capsule and performed a final 4 hour test showed that all systems
were functioning properly.  The finally weight of the balloon train
which includes the capsule, emergency radar reflector, and parachute is
5lb 3-3/8 oz. Capsule is ready for launch.

Performed
some additional testing this past weekend and found that my altitude
procedure was not working properly.  It took several hours but I
finally found the problem.  It seems that I was overwriting my altitude
value.  Each cycle of the GGA routine would reset altitude to zero and
then assign the actual value.  In a serial configuration this would be
ok but I am working in parallel fashion now and that caused my
anomalies.  The altitude procedure would slow down the external lights
but never stop them.  You can see where I am going.  One time it would
be zero and the lights would flash, the next time they would be the
actual value and they would not flash.  Resolved the problem by reading
altitude with a temporary variable and then assigning it to altitude. 

Completed
final testing and the capsule is flight ready.  I set the external
signal lights to flash at 40 pulses per minute below 60,000 feet in
accordance with FAA rules even though I am flying exempt.

The finally weight of the capsule which includes the capsule, emergency radar reflector, and parachute is 5lb 3-3/8 oz

KML File – HAPB-4Test (Right click and "Save Target As", then double click to open in Google Earth)
Excel Spreadsheet used to format KML file

Launch Day (08/31/2008 – 6:34 am)

HAPB-4 was launched and recovered successfully today thanks to the team
of Dr. Thomas Talley and Paul Hubner. And a special thanks to my wife
who couldn’t make this trip but was able to provide us with 0 hour
prediction data, monitor the flight from google maps, and assist with
remote recovery.

Released at Lake Whitney State Park at 6:34 am
GPGGA,113428,3155.4589,N,09722.1585,W,1,08,1.8,166.8,M,-24.0,M,,*7B

Burst occurred at 8:19 am and reached an altitude of 106,384 feet.
GPGGA,131942,3153.1798,N,09747.9075,W,2,10,0.8,32426.0,M,-23.8,M,,*761

Landed at 8:42 am in a field
GPGGA,134228,3153.2346,N,09752.2611,W,2,09,1.0,341.7,M,-23.8,M,,*7AC01

 

Launch

We lost signal during the descent from 65,889 feet when the lower half
of the bi-pole antenna broke off. We were able to reacquire the payload
at 18,366 feet and finish tracking it to the ground. More to come.

Recovery (08/31/2008 – 8:42 am)

Damage Assessment

The
capsule suffered a fair amount of damage. The capsule lost most of the
bottom half of the bi-pole antenna at 65,889 feet. It appears this was
due to the balloon and parachute whipping around the capsule and it was
sheared off from the force. It looked like a clean cut through the
plastic jacket, dielectric insulator and centre core. There were a few
strands of metallic shielding that were torn and ragged.

The
inside of the capsule had extensive damage. The LCD portion of the
instruction panel snapped off from the impact, however, the LCD was not
damaged. The jar of impact damaged the Coolpix L15 camera and the lens
is now stuck in the "ON" position and the camera itself will not turn
on. It is also possible that the trigger wire was pulled loose from the
camera at impact but I speculate that it happened at 99,412 feet. This
is the altitude that the camera stopped taking pictures and where the
trigger wire probably came loose and pulled away from its contacts.
Upon additional inspection of the camera there were over 3 gigs of
memory available and almost full battery life remaining.

There
were also video issues with this flight. The standard definition camera
stopped recording at 81,647 feet due to power failure. The inside
capsule temperature was recorded to be 41 F. The batteries had been
replaced earlier in the week and may have been previously used. The HD
video recording was the most disappointing. It was unable to focus most
of the time during the flight and it stopped recording at 56,804 feet.
Upon retrieval there was sufficient power to play the video so it was
not a power issue with the recorder and had over 2 gigs of available
memory. The inside capsule temperature at that altitude was 52 F. The
cause of the failure is unknown.

The capsule sustained
minor damage.  Several small twigs punctured the bottom of the capsule
and the insulation has been compressed a 1/4" by the electronics due to
ground impact.  I have calculated the impact was approximately 2092
feet/minute (23.77 MPH) based on my final recorded readings from the
flash drive.

The MPFC and telemetry system did not suffer any damage and were still intact and working when we located the capsule.

http://www.hapb.net/FLVPlayer_Progressive.swf

http://FLVPlayer_Progressive.swf

Damage Assessment

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