Warming up the thruster that will ram LOHAN to glorious heights

Project team prepares to shove pocket rocket in toaster

Two is one, one is none

In fact, we have two heaters - just in case one succumbs to the rigours of testing - so we plugged in the second to check it was in good health. Here's the result, again when sandwiched between two styrofoam sheets:

Graph of our second heater test, between styrofoam sheets

That's all well and good, but when the heater makes its way to the stratosphere, it'll be wrapped round the aluminium motor casing, and sealed on with heatshrink. A layer of space blanket between heater and plastic will provide some insulation.

That's the plan, anyway, so we need to have some idea of whether the thruster will stay toasty without extra insulation.

Accordingly, we glued an aluminium sheet on top of some styrofoam, taped the heater on top...

The heater on top of an aluminium sheet, with space blanket on top

...and then stretched some space blanket over the heater, having first stuck in a K-type thermocouple to monitor the temperature:

The space blanket taped tight on top of the heater

In the best tradition of garden-shed bodging, we then slapped on a rubber sheet to simulate the heatshrink. It's actually a piece of shower mat, complete with designer suction pad motif:

The rubber mat taped on top of everything, with the battery and temperature meter connected

Unsurprisingly, without the benefit of a styrofoam sandwich, and with the aluminium sheet slurping up the output, we won't be frying eggs on this test set-up:

Graph of our third heater test

This may look like a very modest temperature rise, but there's one thing we have to bear in mind: the lack of atmosphere at altitude may prevent heat radiating away from the motor.

In fact, this effect is exactly why you don't have to heat electronics on High Altitude Ballooning (HAB) flights. On the contrary, you have to be careful they don't melt down.

So, we know what you're thinking - and we agree that the only way to find out is to send the test rig heavenwards with a temperature logger and see what happens. Watch this space... ®


Further LOHAN resources:

  • New to LOHAN? Try this mission summary for enlightenment.
  • You can find full LOHAN coverage right here.
  • Join the expert LOHAN debate down at Reg forums.
  • All the LOHAN and Paper Aircraft Released Into Space (PARIS) vids live on YouTube.
  • For our SPB photo archive, proceed directly to Flickr.
  • We sometimes indulge in light consensual tweeting, as you can see here.

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Paper Aircraft Released Into Space

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