High altitude balloon payload, from Sable-3 discussion Options

[djellison]

http://www.unmannedspaceflight.com/index.p...20&start=20

We began talkin about a UMSF balloon - and who know what might happen if enough people think about something hard enough, thoroughly enough and long enough.

How's about this as a starting point.
http://vpizza.org/~jmeehan/balloon/ with http://www.chem.hawaii.edu/uham/part101.html as an important regulatory start point (I'm going to look up the UK regs for this as well)

http://www.srcf.ucam.org/~cuspaceflight/nova1launch.html is also very impressive - all done in the UK

This http://www.makezine.com/blog/archive/2007/...video_podc.html is particularly impressive - I like the multiple-cameras slant.

Anyway - thought I'd get a thread going - this is an idea I like too much to let it gather dust in a corner - the one thing that I think would be nice to achieve is self-portraiture of some sort - think Beagle 2's WAM etc....perhaps in a corner of the FOV of one of/the imaging system. What sort of limit's should we set ourselves? 1kg 10x10x20cm? (sort of 2U Cubesat-on-a-diet budget)

Doug

[djellison]

Well - I think with these cheap cameras I've got coming - I'll tick the low-cost, wide angle boxes and bolt on a simple timer circuit. I need to establish what, if anything, is happening when the shutter is pressed ( is their current or voltage involved that might feed back from one camera to another etc - and does that even matter if they're all identical anyway )

With multiple cameras, the independent timer circuit is going to be a better bet than relying on the intervalometers of whatever type of camera we have - as I imagine they would drift out of sync with one another Power is still a 'hmm - what to do' issue - because the FM APRS Tx needs a power source as well - although it will happily run of a standalone 9V for a week or more. Amazingly - there are some C and D recharable cells that run to 5000Ahrs and 11000 Ahrs respectively. A pair of those for each camera would give us all the juice we would need (5000Ahrs is twice the capacity of an excellent AA)

I was worried about the cold on the GMC - but going for the most simple possible solution - http://www.bargainboards.co.uk/P/MyCoal-Fo...mers(1252).aspx - would make the problem go away entirely.

Once I have chute, box, cameras, FM APRS Tx, GPS - I can think about the mass budget and figure out how many Whr's we can get into it. If it's looking desperate then in order..things would get culled like this

3rd camera
2nd camera
GMC
IBS
Replace 1st camera with GMC fitted internally.

The bare minimum is one camera, and the FM APRS Tx & GPS. Then it's that + the IBS etc etc.

If your Loox is properly dead - and ignoring the beggars can't be choosers factor - it'd be brilliant if you could scrounge a similar model so that the dead one can become a mass model.

[AndyG]

I was worried about the cold on the GMC - but going for the most simple possible solution - http://www.bargainboards.co.uk/P/MyCoal-Fo...mers(1252).aspx - would make the problem go away entirely.

Top marks for the heating option - though I would be somewhat wary of enclosing one of these in a thermally insulated sealed box. Could get toasty! Any idea of their wattage?

And I'm sold on the idea of flying a thermometer - Maplins do a 100k Bead Thermistor (for 90p!) that works down to -55C. But if a thermometer is to go - then a manometer's a must, too, in order to check altitude.

Andy

Edit: Rs Components offer a suitable manometer - but it's £40! Surely they can be found for less than that?