Original URL: http://www.theregister.co.uk/2014/03/14/lohan_dommsday_box_test/

Punch and Judy face Blofeld in LOHAN doomsday box test

Black leather chair? Check. White Persian cat? Check

By Lester Haines

Posted in SPB, 14th March 2014 12:38 GMT

As we recently announced, the British contingent of the Low Orbit Helium Assisted Navigator (LOHAN) team will assemble in Blighty on 5 April for the final test flights before the launch of our Vulture 2 spaceplane.

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The first stratomission, dubbed "Punch", will lift a small Cesaroni rocket motor to 20,000m to definitively establish if we can get ammonium perchlorate composite propellant (APCP) to ignite at altitude with a kick up the backside from our custom igniter.

The second flight, named "Judy", will test the space-grade Polyimide Thermofoil flexible heater rig, intended to keep the spaceplane's full-fat Cesaroni 54mm 3G toasty.

While all of this promises top entertainment, it occurred to us that we might as well use the Judy flight to take the Big Red Abort Switch To Release Aerial Payload (BRASTRAP) doomsday box out for a spin.

BRASTRAP is designed to provide an emergency balloon cut-down should the LOHAN payload threaten centres of civilisation.

The box of doom itself was constructed by LOHAN team member Dave Akerman...

Dave Akerman's emergency cut-down box

..and packs a Raspberry Pi...

The interior of the BRASTRAP doomsday box

...programmed to send an abort text message via wireless net connection to a RockBLOCK Iridium satellite comms unit aboard the LOHAN fantastical flying truss's electronic enclosure: Top and bottom views of the RockBLOCK

Once the RockBLOCK's got the message, it commands an attached Arduino Mini Pro to fire a pyrotechnic cut-down using a MOSFET:

Top and bottom views of the RockBLOCK-Arduino sandwich

There's more on the RockBLOCK-Arduino sandwich, and just how the abort system works, right here, and work it certainly does.

Back In September last year, we did a ground-based doomsday test featuring, agreeably, a pair of pliers. The cut-down itself was put together by Rob Eastwood and Paul Shackleton, and comprises a stainless steel tube with a hole through which the payload suspension cable passes.

A steel bolt inside the tube, driven by explosive charge trigged by E-Match, blasts its way across the cable aperture, severing the cable and cutting free the payload.

Montage of video stills of the cut-down firing

Quality stuff, although it'd be nice to check if it's as impressive up in the stratosphere.

Since the Judy flight doesn't have to hit any particular altitude, we'll use BRASTRAP to release the payload after an hour or so, by which time we'll have recorded enough temperature data from the rocket motor heater.

We're currently sourcing a black leather chair and white Persian cat for Dave, so he has the proper accessories for pushing the big red button. We'll draw lots to see just who cops the piranha pool plunge in the event the doomsday box system goes titsup and someone has to "pay the price of failure". ®


More from the lovely LOHAN:

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
  • Random Engineering logo
  • Space Graphic Solutions logo
  • 3D Robotics logo

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