Weather Balloon - Summer 2011

Manager: Derek
Team: Eric, Joel, Jamie, RyanC
Premise: Launch a high altitude weather ballon with video and still photo capabilities


We are going to launch a weather ballon to achieve three goals:

  1. Obtain pictures and video of St. Louis and the earth from high altitude
  2. Execute a well organized project to attract people to Arch Reactor
  3. Provide a good knowledge base and experience for future flights

A KCI1200 balloon is capable of reaching in excess of 90k feet.  We'll have a payload containing a still camera, HD video camera, high altitude GPS, cell phone to broadcast low level GPS and an Arduino logging sensor information.

Team Members

Derek, Eric, Joel, Jamie, and RyanC

Timeline and Milestones

July 30thGrant submitted to AR
July 12thGrant Approved
July 14thOrdered balloon,gps,phone and camera
August 2ndPostponed target date
 Passed HAM test
August 5thAll materials have arrived
August 13thTarget Launch Date
Sept. 11thNew target launch date with full moon


Weight Catalog

  • Parachute            68g
  • Video Camera  160g
  • Cell Phone          84g
  • A560 no bat       166g

Team Notes

  • Need to look into IR and blue filters
  • Moon path

    On Aug 13 the moon rises at 7:41pm and the sun sets at 7:58pm


    At 8:10pm the moon will be about 4.5 deg above the horizon.

    At 8:30pm the moon will be about 8.15 deg above the horizon.

    At 8:45pm the moon will be about 10.85 deg above the horizon.


    The moon will be approx 240,000 miles from St. Louis.   At 80,000 feet, your camera will only be 15 miles off the surface, which is a difference in angle of 0.006%.  So however far you want the moon off of the horizon in your pictures, you can safely use what you’d observe from the ground.





Antenna Stuff


APRS Notes:

FAA/Safety Related:

FLDIGI info:


Programming Notes:

<M0JSN> what did you use in the end?
<Upu> ong TEST=((float(LONGM)/60.0)+(float(LONGS)/3600.0))*1000000L;
<Upu> long TEST=((float(LONGM)/60.0)+(float(LONGS)/3600.0))*1000000L;
<Upu> sprintf(TELEMETRYSTRING,"$$AVA,%i.%06li",int(LONGDEC),TEST);
<fsphil> heck of a calculation lol


CHDK Script:

arch reactor balloon script v5
Authors: Arch Reactor Hackerspace (Jamie Bilinski, Derek Sigler, Eric Geldmacher, Ryan Castanho)
Tested on: A480 (Digic 3)

Uses propcase lib
@title ArchReactor Balloon Script
@param t Min Sec Delay between images
@default t 10
@param j Number of JPEGs/cycle
@default j 10
@param d Number of Raw/cycle
@default d 1
@param e EV Bracketing delta/6
@default e 4
param l est low alt mins
default l 45
param h high alt time mins
default h 110
param r est reenty time min
default r 185

h=((t-1)*1000)+930 --adjust for write time
if h < 9000 then w=9000-h else w=1 end --process delay ms after RAW shot

function flashoff()
 set_prop(142,2) --no flash
 while not get_prop(142) == 2 do
 return true

function setfocuslock()
 set_prop(6,3) --infinity
 while not get_prop(6) == 3 do
 return true

function snapraws()
 for i=1,d do 
   until get_shooting() == true
 return true

function snapjpgs()
 for i=1,j do 
   until get_shooting() == true
 return true

function snapevbrac()
 for i=1,e do
  if (evi-(i*32)) < 1 then set_ev(1) else set_ev(evi-(i*32)) end --may need in certain light?
  until get_shooting() == true
  until get_shooting() == true

--{{ Maybe next time!
function logtemp()
print get_temperature(0)
print get_temperature(1)
print get_temperature(2)

click("shoot_half") --in case A480 is in play mode
 play_sound(4) --beep each cycle so we know it's running
 until false
reboot() --meh


*replace "{" and "}" with right and left bracket


Notes from IRC:

<priyesh> on an NTX2, would you permanently keep the EN pin high or use the microcontroller to take it high only during transmission?
<Darkside> keep it high
<Darkside> we've found that fldigi demodulates RTTY better if theres a constant carrier
<fsphil> unless you're after power savings for a long flight, that's pretty much the only time you'd need to toggle EN
<Darkside> if you don't have it, it can loose the first few bytes as it synchronises
<priyesh> Darkside: ahh. thanks for the advice
<Darkside> sode*
<jgrahamc> On GAGA-1 I had EN tied on permanently because then it's easy to find the carrier.  Also, it doesn't draw much current and there's a 'startup time' whenever EN is enabled.


Posted by
Derek Sigler's picture
Derek Sigler
on Wednesday, July 6th, 2011
Filed under balloon
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  1. Laser Workshop Night
    • Start time: 07:00pm
    • End time: 08:00pm
    • Feel free to come by to learn how to use the laser cutter, talk about laser cutters, work on laser cutter projects, etc!

      Contact Person: Travis

    • View this event in Google Calendar


  1. 3d Printer Meetup

Sunday, March 29th

  1. Silk Transfer Easter Egg Dying
    • Start time: 01:00pm
    • End time: 04:00pm
    • Arch Reactor crafting / upcycling workshop, Alix is going to teach us how to silk dye eggs. Free

      Facebook event page:

      Did you know you can dye an egg with a silk scarf? Alix will show us her secret method. Bring your imagination and crafting supplies. Bring cool easter related projects you have done to show off.

      Bring a snack or wine to share. AR has a microwave, refrigerator, and sink (cold water only though).

      Crafting stuff to definitely bring:
      - blown eggs (See instructions below). If you cannot figure out how to do this, bring unblown, raw eggs and I will show you how. Use white eggs only, any size. Any white eggs will work but free range ones tend to have thicker shells and so are a bit easier to work with.
      - brightly patterned silk fabric. It must be 100% silk. Neckties work best, the uglier the better. I will bring extras of this so if you don't have any, that's OK.
      - egg carton or other egg container
      -small buttons. I will also have extra of these.
      -glue gun, if you have one.
      - scrap cotton fabric in a light color. An old white t-shirt works well.
      -wooden skewers and a piece of foam to make a drying rack. You can get a foam wreath base from the dollar store. Alternatively, one of those cardboard egg drying things from a commercial easter egg dying kit would probably also work well.

      This is kind of half show and tell and half hang out and craft.

      You are still welcome to attend and hang out with us even if you do not want to make pretty eggs.


      Blowing eggs is easy! You might screw it up the first couple of tries, so have spares handy. You will figure out the technique pretty quickly.

      To blow an egg:

      1) wash egg with soap and water.
      2) pierce pointy end of egg with a largeish sewing needle. Try to make this hole as neat as possible. If you have an electric drill, use the smallest bit you have.
      3) make a larger hole in the blunt end of the egg. This hole will be covered with a small button, so it does not have to be as neat. You should avoid creating any radiating cracks that could weaken the egg. You can use a variety of tools of this, I personally start with the sewing needle and then carefully enlarge the hole with the needle until it is about the size of a pea. An electric drill works great for this if you have one.
      4) insert a wooden skewer or similar object into the larger hole and thoroughly swish it around to break up the insides of the egg.
      5) hold egg over a small bowl. Turn it so that the bigger hole is facing downwards, and blow into the small hole. You should not have to blow too hard. If you are giving yourself a headache, stop and try enlarging one of the holes, or swishing the insides up better with the skewer.
      6) when you have blown out the egg, run a little water into the larger hole and shake it up to rinse out the insides a little, then blow out the water. You can skip this step if you want, the eggs will get cleaned out naturally during the dying process.
      7) make an omelet.

    • View this event in Google Calendar
  2. Hack Something!

Tuesday, March 31st

  1. Shop Training

Friday, April 3rd

  1. 2600 Meeting
    • Start time: 06:00pm
    • End time: 10:00pm
    • Arch Reactor is proud to host the only St. Louis 2600 meeting. More details about 2600 can be found at

      All 2600 meetings are open to the public. Contact

    • View this event in Google Calendar
  2. First at Science Center