Electronic guru needed

[treehog]

I have the possibilty to launch a weather balloon which should reach 100,000 feet where it will take some photos and return by parachute down to earth

The problem is to put on board on some suitable electronic tracking device so as to be able to find the balloon after its flight

Our favored idea is to use a cheapo gps coupled to a cell phone (european system) so as to supply a down link

Does anybody know how to achieve this this or knows a another idea which can do this at a buget of 250 euros or $300 approx

Launch date is april 10th so the desire is to use of the shelf components as apossed to electronic kits


Ralf

[DanSavage]

Originally posted by treehog
I have the possibilty to launch a weather balloon which should reach 100,000 feet where it will take some photos and return by parachute down to earth

The problem is to put on board on some suitable electronic tracking device so as to be able to find the balloon after its flight

Our favored idea is to use a cheapo gps coupled to a cell phone (european system) so as to supply a down link

Does anybody know how to achieve this this or knows a another idea which can do this at a buget of 250 euros or $300 approx

Launch date is april 10th so the desire is to use of the shelf components as apossed to electronic kits

Ralf

Ralf,

Search around the web for high-power rocket suppliers. They might have the off-the-shelf hardware you're looking for.

Dan

[treehog]

A lot of the rocetry stuff referers to HAM gear such as T400 Transmitter

Allthough good for 15 miles range they require all the problems and licence requirements of ham

Our preference is a GPS that comunicetes through a cell phone back to base where another cell phone is connected to the laptop and states the present position of the balloon

Due to the high speeds of upper layer winds the average balloon can traverse in excess of thirty miles in it two hour flight and sometimes in excess as 200 miles

The cell phone would always be able to contact a cell mast

Also in europe as we follow the balloon we have travell in the car at realitivly slow speeds to stay inside speed limits etc

I will keep tring all sources including ham

thanks Ralf

[William A]

How 'bout one of those animal tracking systems ?

Kind of pricey, maybe you could rent one.
If you could, don't tell them what your going to use it for and get the insurance option.

[vintage1]

I thibnk you won't have problems staying fairly close to the balloon. When one landed just next to my back gaden, the chase vehicle was only 2 miles away.

You might do worse than simply have an audible alarm, and almost any low power transmitter on board, and use qa DF type loop to get bearings on the downed equipment.

I believe 455Mhz is an allowable band, or you could probably gut a 27Mhz radio system and use that. Coupling up to a cell phone may not work as well as you think if the package lands in a dip in the ground. Its better ot have two vehicles take accurate cross bearings on the transmitter as it lands, and then draw lines on the map and work out where it is, and then get it to beep you in for the last few meters.

[treehog]

To day I rang a major supplier of tracking device companies here in europe
I outlined that me and the other students in our college needed one of thier gadets which is a cell phone strapped onto a GPS
Well they contacted our college and confirmed we were telling the truth so they have chosen to give us one of these tracking devices for free( but we have to come up with the publicity for them)
COOL DEAL as the tracking device costs in excess of 1000euro or $1100

Now that we have the tracking device in route to us we can concentrate on our second launch where we will try to use a robotic glider plane to return the equipment back to earth

alway knew I would find a use for my trusty 2.5 metre discus glider

Ralf

[Weisse Luft]

Been done in Vancouver BC. 100k feet should be possible but the balloon used limited them to 74,000 feet. They lost the glider on the last flight due to winds.

Here is the link:

http://members.shaw.ca/sonde/

[treehog]

He was lucky Canada is big but euro zone ATC regulations will force project to be done much more slowly here.
Its going to be seriously difficult to get the permissions of the french
Thier cool eneogh about the weather balloon as lots of them get launched every day.
The centre of france has a lot of empty space and with suitable planning and the spirt of educational science should be possible to get the permissions fingers crossed
Well if not can look at Spain, Poland,or eastern euro zone counties

The first balloon launch will carry a few packs of nicads and nimh coupled to dummy loads to test affects of extreme temperatures

Then a process of several balloon launches (with glider)to low heights 5000-10000feet or similar to verify everthing works before going to bigger height estimate it will be 2005-6 before 100000k would be a reality

another link with balloon info thats interesting
http://vpizza.org/~jmeehan/balloon/

Ralf

[AndyKunz]

You can do your low temperature testing in an environmental chamber. This also allows you to control humidity, rates of change of all variables, etc.

Much more scientific process than launching a balloon with a dummy load.

Plus you don't need special permission, AND may gain yourself a sponsor in the process.

We use these chambers every day at my office.

Andy

[treehog]

At 50000ft the temperature is low something like -50c
At 100000ft the teperature is high something like 60c

The balloon wil go from 0 to 100000ft in one hour approx
passing through the two teperature extermes in every half hour approx

We are guestimating that we will loss 50% of cell capasity as a result of this temperature extremes both on the way up and on the way down

The college only does busness studies and computer programming
(the team are all programmers except me in I have studied and worked as electronic teck in the past)

It dosnt have any enviormental chambers or even a measly fridge for students to use

We descussed simulating as much as possible on the ground but figured by the time we got through to other colleges organized time from thier facilities it would consume too much time


We decided that the best simulation of the problem was better done in the real world as battery failure would jepordize the project

Most electronic items sold in the non milatary world is specified to operate at -5c to 50c celcius

The milatry stuff can operate -50 to 60 celcius approx
milatrary stuff cost too much

So we have devised tyrail and error system of testing

We will bung the electronis into a domestic refridgerator which gets to -30C to see affects at these temperatures
whatever passes this test will go onto the next test

we intend to haul up the electronics packages such as servos and test run them first attached to balloon

The servos might be 10 servos and with luck only 1 or two fail
That would leave us with 8 or 9 servos tested that showed signs that they could tolerate this enviorment

So on our second launch the glider will go to 5000ft be realeased and the balloon with test equipment will continue on its journey testing out more gear such as servos batteries etc

The biggest risk to the project is some of the team would prefer an easier project like a lego mouse crawling around the lab floor
as the exams in java php sql OS etc are really realy hard

The proffsor will decide mid next year if its a mouse or a glider project that will be worked on
He fed up with every year watching mice going around the lab
but the budjet for the robotic projects is 500 euros total and mice dont eat up money like balloons so if sponsorship isnt forthcomming we will be programming mice


Ralf