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Pegasus V


The plan is to develop a system which is able to control the direction that the sideways facing camera takes its picture. There are a variety of ways of doing this including actually controlling the spin of the payload (which is technically very challenging). Instead using a digital compass to calculate spin it should be possible to set the camera to trigger at an appropriate moment (taking into account the spin rate) so that the picture takes when the camera is facing the chosen direction.


  • Gumstix + GPSstix
  • Nokia 5110 (BTUART)
  • Olympus mju 300 (3.2 MP) - Facing sideways - triggers every 30 seconds
  • Premier DS-3081S (3.0 MP) - Facing up - set to video (will video till it dies of cold/runs out of space/batteries
  • 434 Mhz 10mW radio (toggled by gpio with morse code of location and altitude)
  • i2c Digital Compass
  • 4 x AAA lithium battery pack
  • 1 x 9V battery


Pretty much nearly there, all the hardware is in place so its now a matter of sorting out the software:

  • Radio - done, transmits morse code at 11wpm with a format of PEGVlat/long/alt on 434.075mhz
  • Phone - done, two texts to ground control then one text to zeusbot and repeats.
  • Camera - done
  • Compass - done, being annoying and not being reliable
  • Cutdown - done, needs testing + software

Pictures of the payload here

Launch One

Launch Plans


  • First attempt - Saturday 28th April at 10.00am from Churchill
  • Weather - good, low windspeeds at all levels.
  • Flight Plan - climb as high as possible, only cutdown if strays out of 100km radius.
  • Setup = Balloon – cutdown – parachute – Pegasus V – mc-2


  • Pegasus V will be broadcasting on its radio on a frequency of 434.075mhz with a power of 10mW its position and altitude in the format of “PEGVlat/long/alt”. If anyone picks it up it would be great if you could log the data (send it to and if you are feeling proactive there are a couple of ways you can get involved in the tracking. Though only the beginning of a distributed system the IRC bot on our channel #highaltitude is capable of relay positions etc - here is a little guide:
    • On IRC doing !position will relay the last known position of the payload
    • All the positions received by zeusbot are logged here.
    • Positions can be sent to zeusbot by emailing, leave the subject empty and put in the main text: “pegV /lat/long/alt/name”
    • Using an sms to email system you can text a position to 07766 40 41 42 using the format: “ pegV /lat/long/alt/name” (The payload will also send messages to this number every 3rd attempt to text it to ground control).
    • Finally you can play the position onto a map by entering lat,long in the form here (need link)

mc2 riding as a secondary payload - 200g - GPS PIC based tracker transmitting mc pseudo morse on 434.075 (subject to test with peg V). Morse as follows (count the number of dots, add 5 for a leading dash - two dashes for 0) :-

1 .2 ..3 …4 ….5 -6 -.7 -..8 -…9 -….0 - -

Message format:- latitude <space> altitude <space> longtitude about once per minute latitude and longtitude are just minutes - altitude in meters

Things to do

  • Finish payload - jcoxon
  • Helium - rocketboy now has 4 cu m (also if ed and henry can get hold of the engineering department helium that would be great)
  • Balloon - got
  • Parachute - rocketboy - still have the 36“ from Peg IV - yep will bring
  • Cutdown - rocketboy - yep will bring
  • Get Permission for Churchill - Ed - sorted
  • CAA contact - Henry?
  • Charge batteries - jcoxon
  • Phone Credit - jcoxon
  • Fix Compass - jcoxon


Mission Complete

Payload was retrieved from the edge of a field near to Kettering, pictures, log file and kml file here. Reached 10155m after a flight of 1 hour and descended slowly by parachure after cutdown.

Things that worked well
  • Cutdown
  • Radio
  • Phone
  • Camera
Things to improve
  • Don't underfill the balloon!
  • Add ”-“ to morse code software to allow payload to move west of 0 longitude!
  • Actually get compass to work (requires rewriting compass program)
  • Fix zeusbot text system
  • Fix upward facing camera

Launch Two

Launch Objectives

  1. Get compass to log bearing and also calculate rate of spin
  2. Get a panoramic shot every 10,000ft, using the calculated rate of spin and known time for a picture to be taken once triggered we could set it up to attempt to take pictures at all angles which could then be stiched together into a super panoramic.
  3. Finally fly mc2

Launch Plans


  • Same as Launch One - radio and phone performed well - few changes to the software should improve it e.g. addition of ”-“.

Things to do

  • Fix morse code gen program adding ”-“ done
  • Have 2 speeds of morse code - 6wpm and 11wpm which will allow decoding by hand if required. done
  • Rewrite compass program - get it to log to a file, calculate spin rate nope
  • Write code for panoramic shots todo

Launch Planning

Things to do
  • jcoxon
    • phone credit
    • batteries buy/charge
    • memory card
    • testing
Things to bring
  • jcoxon
    • payload
    • parachute
    • Nova Radio
    • Yagi
    • Car
    • Portable GPS
projects/pegasus/pegasus_v.txt · Last modified: 2008/07/19 23:33 (external edit)