Balloon, Mark 1 - "Hello Kitty"

Mission Objectives

  • Lightweight payload.
  • Beacon CW.
  • Timed or Short Duration flight.
  • Foxhunt retrieval.

Launch Date

Sunday, 10/6/2013. 3:00pm EST. East Hill Plaza, Ithaca, NY.

Technology

Balloon Design

Parachute Size

I ran a MATLAB simulation and came up with these results:

   __Input:__
   Cd(Coefficient of Drag):  0.75                 = 0.75
   Parachute Diameter:       12 [in]              = 0.305 [m]
   wind speed:               22 [ft/s]            = 6.7056 [m/s]                     
   __Output:__
   vxfinal: 	               22 [ft/s]            = 6.7056 [m/s]
   vyfinal: 	               15.6022 [ft/s]       = 4.75 [m/s]
   Kinetic Energy at impact: 0.56477 [ft*lbf]     = 0.766 [J]
   Max Force:                0 [lbf] at 500 [ft]  = 0 N
   

Cornell Rocketry has light weight parachute that is 12[in] diameter.

Project weight

Element Weight
Mylar Balloon 1g
Parachute & rigging 2g
Nichrome and lead wire 5g (est)
Radio 35g (Case partially removed)
AA Batteries 37g
CR2032 Battery 3g
Microcontroller board 20g
Waterproof packaging 10g (est)
Total 113g

Electronics Design

Code Design

set_timer(1 hour);
while(true) {
  transmitter on;
  send_morse("W2CXM/BALLOON");
  send_tone(10);
  send_dead_air(10);
  transmitter off;
  sleep(30);
}

Testing

  • Battery testing of the (3) AA Energizer Ultimate Lithium revealed that we were able to successfully transmit for 9-10 hours before the batteries lost sufficient power. This well exceeds our mission requirements - aka “Find it before dark”.
  • Testing with 6 pound test fishing line shows that an Estes rocket igniter will cut it very easily. Before the igniter even catches fire, in fact. Further, the igniter seems durable enough to support the 100g payload during heavy jostling. We will suspend the package from the igniter for this mission.

Final Cost Estimate

Element Cost
Mylar Balloon(s) & gas $15
Parachute $5
String $0
Nichrome and lead wire $6
Radio $20
Battery $20
Microcontroller board & components $20
Waterproof packaging $0
Total $86

Meetings

Last modified:: 2013/11/03 09:59