This is rapidly becoming my favorite topic.

That is so cool Doug. Gotta get me one of them things.

Tonight I'll try and do a little vodcast thing about all the stuff I've got and how it's going. When the packet watch came up and 'NOCALL' appeared - I actually punched the air and screamed "YES! - NOW we're on the way". Need to get a serial cable so I can tweak the MiniTrak's settings.

Doug

Can't beat a few Ents at the end of the garden.

Meanwhile, how come the unit returns a course (82 deg) when there's no speed?

Confused, Andy

Well - the course remains once you're stopped I think (technically, it would then become a heading rather than a course0- and as it got more sat's ( it was stuck up against the window to get sat visability) it updated the location, so the motion from the first rough position to the later more accurate position was 80ish degrees ( which, in retrospect, is about right - the first plot was SW of the later one.)

Doug

The only contribution I've got to make to this is enthusiasm-so here it is: GO DOUG, GO BALLOON!

Yes...Ad astra per scientiam, Doug! ...and please remember to let go of it at launch while both of your feet are on the ground...

Some more bits and pieces have arrived - but there are still a lot of 'unknown unknowns' that we'll need. Thus ignore the %'ge at the end...it's a flawed figure anyway as each step from 1 to 7 probably requries as much time and effort as the cumulative time and effort of all previous steps. I'll do a Vodcasty thing this week - a UMSFB1 Show and Tell.

Doug

Time to start a naming contest yet?

To make things different, you could require people justify the name choice by writing a haiku in its support

--Emily

elakdawalla
will doug let us really do
haiku named balloon?

And to start taking entries for the compulsory 'fly your name to...'

Just popped home - the mirrors have arrived - that's all the prospective imaging payload in place - except a final choice on powering them.

The naming is one of those messy things that I've simply eradicated by acronym deployment. UMSFB1 (then 2, 3, 4, 5 etc)

And as for flying your name...there will be just one name flying onboard - it shouldn't take a genius to figure out who's (given the sort of flight involved) but not quite sure how to action that just yet.


Doug

PICAXE AHOY

Got a few relays, and a buzzer, and some AA battery holders today. Wasn't getting 4-5v out of the 3xAA battery holder that the picaxe kit came with - so I got a 4 cell holder, put NiMH's in it ( 5.2v measured ) - and bingo - I was able to program it via the USB cable. Did a few BASIC programs that triggered the buzzer - and bingo



'Bzzz............Bzzzz'

OOo



"Bzz.Bzz....Bzz..Bzz......"

YAY!

Maybe tonight, but certainly later this week ,I want to hook that same 'bzzz' onto a couple of different types of relay I've got - see if they'll do the job for the cameras.

Doug

IT WORKS

I did a simple



The output of output zero was then wired to a bit of breadboard that powers a relay ( the top one - http://www.maplin.co.uk/module.aspx?Module...5&doy=15m10 ) . The Picaxe project board runs on 5v, and each output will handle 800 mA. The relay's coil is spec'd to be about 500 ohms - I'm measuring it at something like 480ish at the breadboard. So it draws a current of 10 mA for that second. The outputs of the relay then pop to another tiny bit of breadboard which I simply used to make it easier to hook up to the shutter release cables from the camera. The camera is hard-wired to the C-cell sized battery holder.

At first it wasn't working - but then I realised I was asking it to to 'high 0' and then 'low 1' which was just stupid - the Gumby school of coding.

But now - it works Attached - what our sofa looked like just after I turned it off.

Would that be Mr Helium?

Mr & Mrs Latex.

I'm hoping that somewhere obvious on it will be a name. As in "If found please return to Doug Ellison....."

Or maybe you should specify on which side of the Channel -- Doug in the UK, Climber or Ant103 in France.

One of the payloads that they let aloft from Cambridge made it to Denmark - and was returned

Doug

Better include Bjorn's contact info, just in case.

Just contacted the CAA ( UK's version of the FAA ) asking for regs on unmanned balloons, offering to launch when and where suits them, rather than stipulating such things from our end.

Meanwhile, I"m hoping that by this weekend, I will be able to have all cameras breadboarded ( three internal and one external ).

I'll be switching to pairs of AA Lithium (low temperatures, what low temperatures - they just don't care) cells in series ( to give me the 3v that the cameras require ) but probably four pairs for the three cameras, a further two in parallel for the GMC, and three or four for the PicAxe. The APRS will be off a single 9V

Doug

Video Update 1 - Envelope, Parachute, Gondola
http://youtube.com/watch?v=rkug-Z9Xm5Q

Video Update 2 - Cameras
http://youtube.com/watch?v=gu3P3O3Z3eU

Update 3 - Tracking - on it's way later.

Good show! All you need is a whiteboard that you can draw on to illustrate your concepts.

A short piece in the Guardian newspaper this week reported that US Meteorologists used to put signs on their balloon instrument packages, warning finders that they would be fined for not returning the contents.

Personally I think UMSF should take the "reward" route.

Andy

Good show Doug.

Parafoils - Genius!

Coming back to the camera pointing issue that you talked about. With two cameras, I'm as torn as you are about having one landscape and one portrait vs both in portrait. I don't think there is a lot in it, and determining which is best is probably rather dependent on how much the gondola is swinging. At the moment I think I'm inclined to go with the 'double portrait' mode to, as you say, maximize the coverage from horizon to nadir. A slight clarification from what you said, you probably don't want to mount them to get from horizon to nadir in one shot, we really want to be getting the horizon in as much as possible. So the first should probably be mounted so that the image centre is pointed somewhat at the horizon (maybe a little below). Hence the bottom edge of the lower camera will be at 60-65 degrees, hopefully low enough so that with a few fortuitous swings we get some direct nadir imaging.

If you can do the tests on the field of view and get an idea of what frame rate we can manage (power, memory), I'll examine some images from other projects to try to get some better statistics on the expected gondola motion and then I'll run some more simulations.


Oh, and about mixing units - I now know who I'll be blaming when we loose it on EDL!

James

Man...you need an haircut...

You need a shave

Hahahah... buuuuurn!

Just did...

...and the mark XXIII-or-so could benefit from this in a big way. Assume a 30km release point and a (very poor = easily achievable) 5:1 sink rate, onboard gps and a "clever" payload - it could fly itself back to where it started. Preferably landing in the open boot of the UMSF Support Vehicle.

As to Doug's hair - I'd sooner he was nailing stuff together than wasting time down the boutique, Ustrax!

Andy G

http://www.youtube.com/watch?v=HU2tymr4Rs0

Their plan is, hopefully, to do exactly that - have the payload fly home again. Not a simple problem however. As you can see, getting it to fly straight is non trivial.

Doug

I thought the parafoil's quote came from James burrowing into your videos, Doug. I mean we are all sat watching Gizmo, like myself, aren't we?

Andy

Actually my comment did come from Doug talking about it in the first video.

But I admit, I did then go, "Oooh Doug has some more videos" and watched parafoil tests and Gizmo.

Gizmo may well be involved in the final part of the trilogy If she'll sit still.

Doug

I am assuming that since this is UMSF we don't have to worry about Doug posting a video of him trying this concept vehicle:

Balloon Flight

And I must protest that my UMSF addiction is now spilling over in to my YouTube addiction - Phobos-Grunt updates AND dogs on skateboards?!?!?! Where do I sign!

Part the Third
http://uk.youtube.com/watch?v=U0IJM5EWu9Q

Does the data from the GPS device include ALTITUDE? If not, shouldn't some kind of altimeter/barometer be included?

(The shed looks smaller than it did in the original wide angle photos)

It should. Most standard GPS devices output data in the NMEA 0183 format, and the $GPGAA string includes altitude data, IIRC. However, this isn't referenced to terrain or local elevation but rather to the WGS84 spheroid model of the Earth, so uncertainty of a few meters is a given (although I've also seen GPSs freak out & give whacko elevation data pretty often during flight...)

Well the way to calibrate for that is to take a "zero" reading at ground level prior to launch.

Pay attention Dan

http://www.unmannedspaceflight.com/index.p...st&p=101948

Doug

It's too bad that there's not a compact differential GPS (DGPS) receiver available for greater precision...those things can give you 10cm X-Y positional accuracy wrt the surface, plus largely obviate the altitude freak-outs I mentioned earlier. In the UK, correction signals are transmitted in the 300 KHz band, though, so would have to add a fairly hefty antenna to get any degree of reliable performance. DGPS is mostly intended for maritime use, so most of the available (and less expensive) equipment is too heavy for this particular application.

I have no specific knowledge of lightweight DGPS kit but the antenna for 300kHz shouldn't be a problem. For transmission at that frequency I'd agree than you'd need something pretty substantial but for reception an active antenna (such as http://www.radiopassioni.it/pdf/pa0rdt-Mini-Whip.PDF ) would work well with a length of <100mm and pretty low weight.

Watching this thread with great interest. Brilliant stuff!
Rob

Ah! Did not consider active antennas, just passive. Haven't messed with DGPS since 1998, when I connected a Magnavox MX50 DGPS receiver to one of the automatic direction finder antennas of a C-141 (passive all the way, of course.) Seems the state of the art has improved a bit over nearly ten years (duh...)

I was distracted in my zeal to include some kind of barometer. But I will raise the issue anyway. If the UMSF balloon goes anywhere near as high as the Sable-3 project we are emulating, then we will approach Martian atmospheric conditions, and that alone would be a cool fact to report on.

And that raises another issue. Have we considered the effect of 10 millibars of pressure on each of the components? My first thought is the C-cells and the potential to burst if they are tightly sealed.

If I can log temp, pres and GPS with a second Picaxe unit....I will. I want to do those temp/pres profiles A small cheap pressure transducer is not something I've found yet though.

Doug

Look for the Motorola MPX100AP.

I would be willing to provide this.

Doug,
For a test flight, have you considered a kite? Given a large enough kite, a couple of KG of lift should be a cinch. Also, do you have a list of which components you are using? I would like to get a couple of those cameras for my own experimentation...

In the spirit, we just purchased an Estes Astro-Cam digital camera rocket. Only have had two flights, one a near-tradgedy (flight tube damaged but serviceable) and the other a perfect, if slightly delayed, launch. Videos are at:

http://video.google.com/videoplay?docid=45...44458&hl=en
http://video.google.com/videoplay?docid=41...66003&hl=en

http://www.aria.co.uk/SuperSpecials/Other+...productId=28103 is the camera - although to be honest, I may go with something a bit better or the actual flights - and use one of those for the monitoring camera

Doug

Closest thing I could find is the 3.1 MP version of the catcam camera, a VistaQuest:
http://www.walmart.com/catalog/product.do?product_id=5614773

I might give it shot as a kite-cam for fun. During my copious free time, of course!

The 1.3 MP VistaQuest is what the GMC is.

Doug

High ALtitude Object - HALO

30k balloon. This guy has a detiailed write up of how he did it with some awsome videos and photos of the results.