• Atlas RFM22b Board
  • ATmega328
  • RFM22b
  • 4Mhz crystal
  • 1.8v stepup
  • uBlox Max6 1.8v GPS
• 1x 92cm Foil Balloon

• RTTY 434.342Mhz
• 50baud, 425shift, ASCII-8, no parity, 2 stop
• String: $$$$PICO,99,21:12:01,514980017,-527928,9,7,6,1,3*014E
  • $$$$Callsign,count,HH:MM:SS,Latitude,Longitude,Altitude,Sats,Navmode,Powersaving,Lock*Checksum
• Reboots the radio every 20 strings
• GPS powersaving won't start unless lock has been achieved for more then 5 strings

• Launch time: 02/03/15 15:03:05
• Final data point : 04/03/15 00:57:07
• Total flight time
  • 122040 seconds
  • 2034 minutes
  • 33.9 hours
  • 1.41 days
• Max altitude: 4960m
• Lowest altitude: 12m
• First night time float: 3600m
• First day time float: 4750m

Launch was very easy, winds were approximately 3mph, balloon was filled

• Excellent flight
• Demonstrated that you can do a truly long duration flight
• 2 float periods - night and day float during which it appears the balloon was super-pressured.
• Final descent was due to cooling without sunlight and the loss of helium over the flight meaning it didn't have enough helium to support the payload
• Interesting post launch flight where it appears to have been caught in an inversion layer.
• Payload worked really well, with rock solid transmission through out.

• Would need repeating
  • Aim for 0.5 -0.7m/s ascent rate to get a low night time float altitude which gives you a bit of flexibility for your higher daytime float
  • Need perfect launch conditions - avoid inversion layers and clouds
• Launch in the morning - investigate whether it can survive an sunset early on in its flight profile as it still has enough gas
• Simple ballast system to rescue if it does start to descend
• Fix the uplink to the RFM22b as this would allow some fun with the slow floaters.
• Fly the APRS repeater if flight path has it going across Europe.
• How far could you fly in 33 hours…