To actually see if it is possible to super-pressure mylar/foil balloons - this requires more balloons (of the same size) and a lighter payload. Launching would need a quicker ascent rate and an earlier launch time to make use of the solar heating.

• Lighter payload
  • Smaller battery - 1000mAh
  • Better power saving in the code
  • Smaller GPS antenna
  • Lighter wire UHF antenna
  • Use seeeduino rather than arduino pro
• More balloons - order 4 91cm balloons and see how many we need to use
• Preamble before tx'ing when in modes that have gaps
• Temperature sensor
• Photodiode sensor

• Seeeduino film
• GPSbee
• Mini GPS antenna
• Radiometrix NTX2
• Wire 1/4 wave + radials
• 1000mAh LiPo battery
• Some insulation

• Aiming for 75g total mass.
• Things to buy
  • 1000mAh battery - proto-pic - £6.60
  • More wire - maplins

• purchase 4x 91cm balloons
• swap arduino pro for seeeduino
• rebuild 1/4 wave with lighter radials
• order 1000mAh LiPo
• power saving code