HAPS-1, UMSFB1 redux Options

[djellison]

Next weekend, if everything goes well, a 15x30cm carbon deck will fly onboard HAPS-1 -http://www.pegasushabproject.org.uk/wiki/doku.php/missions:haps:haps-1

One end of the deck will be the flight radio, the other is my responsibility, a single camera (Powershot A560 ), stand alone GPS logger (to 18km), and a small wide angle mirror so the camera can see the payload, the chute and the envelope above.

Still working on a hacked firmware for the A560 - but the intention is every minute will include 15s of video, and then 5-10 stills in fairly quick succession - with the hope that the rotation of the balloon will give us some mosaics out of each section.

More details, some photos etc, later in the week.

[djellison]

Essentially there's not a lot we can do about that... what we CAN do, we do do...

Use Lithium AA cells which dont drop off at cold temps (http://data.energizer.com/PDFs/l91.pdf - OK to -40deg - very expensive at £1 each roughly, but worth every penny)
Give the camera quite a lot of work to do (hence the 4gb card, I intend to fill it on a schedule of 3hrs) thusdumping the 9 whrs of energy from the two cells about as rapidly as possible into the camera which will render itself as heat.
Insulated as well as I can in foam (although the fact that the lens 'opens' means it's not even slightly sealed around the front)
And a 'get up and get down' flight plan to avoid lingering at altitude.

The first, third and last of those has been enough for similar flights in the past.

I feel sorry for the GPS logger on top of the foam -it's only going to have a layer of duct tape between it and the hell outside BUT - thermally speaking, the camera will be a warm glow underneath.

Doing something as simple as a pair of 9v cells dumping to a thin film heating element is just too much complexity and mass. If we mature the project to go for high altitudes or lingering, then I will be aiming to disable the camera's motor-driver lens deployment, keep it stuck out, and match foam around the lens to better insulate.

Of all the things that could go wrong - the camera getting too chilly isn't top of the list by a long long way. DOing it this way has worked for lots of other projects, so I'm happy to go that way. Next time around maybe we log temps internally on the camera, externally on the foam and then in free air under the balloon - using a Picaxe kit or similar.

It's worth mentioning though, that for perhaps 10 minutes, maybe half an hour, this whole schbang will be at 10mbars or less, at -50 degrees, with lots of UV radiation.

Remind you of anywhere

Doug

[ElkGroveDan]

It's worth mentioning though, that for perhaps 10 minutes, maybe half an hour, this whole schbang will be at 10mbars or less, at -50 degrees, with lots of UV radiation.

At least there will be no perchlorates to deal with.

But seriously, I feel a bit like Rip Van Winkle here. Can you share with us some of the history of this version of your project? Last I heard there were too many restrictions in the UK and you dropped the entire balloon idea. Now it seems like 20 years have past and everything is different. What did I miss???