Original URL: http://www.theregister.co.uk/2013/08/20/iridium_arduino_sandwich/

In case of LOHAN flight emergency, gobble THIS Iridium-Arduino sandwich

Space-balloon abort box to feature big red button

By Lester Haines

Posted in SPB, 20th August 2013 08:59 GMT

Pics We recently reported that we'd laid our grubby mitts on a second RockBLOCK Irdidium satellite comms unit - courtesy of Rock Seven.

Top and bottom views of the RockBLOCK

The RockBLOCK, pictured above, can "send and receive short messages from anywhere on Earth with a view of the sky", and it's this latter capability which has now become a vital component of our Low Orbit Helium Assisted Navigator (LOHAN) spaceplane mission.

For our Spanish launch, the Agencia Estatal de Seguridad Aérea (State Air Security Agency) and Aeropuertos Españoles y Navegación Aérea (Spanish Airports and Air Navigation), require an emergency balloon cut-down in the event that LOHAN wanders off course.

Fair enough, so cue the RockBLOCK-Arduino sandwich, as served up by LOHAN team member Dave Akerman:

Top and bottom views of the RockBLOCK-Arduino sandwich

The sandwich comprises:

Dave notes: "At present the circuit assumes a resistor cut-down, for which those batteries are plenty. If the cut-down is a pyro then I'll need to replace the single JST cable with two - one for the pyro and one for the external battery supply."

Whatever we decide, we'll need a cut-down protocol that conserves both hardware battery power and cash. Talking to the RockBLOCK burns juice as well as transmission credits, so Dave has proposed: "I'm thinking of having it poll every five minutes, then if we need it to cut-down I'll send an 'Arm' message at which point it'll poll every 30 seconds for five minutes. If in that time it receives a 'Fire!' message it'll hit the cut-down. Otherwise it'll disarm and go back to polling every five minutes."

Sounds like a plan, but surely we're going to need a box with flashing lights and a big red button on it to command the abort? Yes we are, and Dave is working on something truly preposterous that will, when it's done, require an equally preposterous backronym, in the best SPB tradition.

As is the local custom, we'll leave the matter up to you, our beloved readers, so watch this space. ®


Further LOHAN resources:

LOHAN - A Special Projects Bureau production in association with...

  • 3T RPD logo
  • University of Southampton logo
  • Applied Vacuum Engineering logo
  • Escher Technologies
  • Flashpoint Fireworks logo
  • HAB Supplies logo
  • Rock 7 logo

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