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Who wants to make a FEZ go 90,000ft?


#1

So i want to do a high altitude balloon, something i’ve wanted to do for a very long time. I want to use a FEZ to do this and i’m looking for some partners-in-crime to tag along for the ride! These things are always more fun when done as a group.

I’ve been planning this for awhile, so here’s what i have so far:

The crucial parts of this project would be the:-

  1. Communications link
  2. Camera control
  3. Antenna tracking

I think that would be the most basic aspects we would need and so these will get priority in terms of development and research.


#2

As a starting point for ideas, the balloon payload will comprise several modules:-

GPS module
Internal heating
Sensor module

  • barometric altitude
  • gas sensor
  • dust sensor
  • temperature
  • relative humidity
  • light level sensor
  • IR sensor
  • UV sensor
  • Geiger counter?
  • IMU for roll/pitch
  • compass
  • Voltage(s)
  • Current draw
    Control module
    Recovery module
  • balloon jettison mechanism
  • chute deployment mechanism
    Communications module
  • 900MHz datalink
  • 433MHz datalink
    Video module
  • Camera
  • pan/tilt
  • 2.4GHz link
    Camera module
  • pan/tilt
  • trigger mechanism
    Power module
  • battery management
  • solar? charging
  • primary cells
  • backup/emergency power

The modules and sensors would get shut down if power levels drop too low based on their priority. Every sensor would be able to get disabled.

Groundstation will need:-
I intend to mount most of this in a stepper controlled “radome” attached to the roofrack on my car.

Communications module

  • 900MHz datalink
  • 433MHz datalink
    Video module
  • 2.4GHz receiver
  • video recorder
    GPS module
    Antenna tracking module
  • az/el mechanism
  • compass
  • barometric altitude
  • Yagi antennas
  • Patch antennas
    Control module
    Computer
  • GoogleEarth/OziExplorer
  • sensor tracking
  • various data displays
  • controls
  • prediction and extrapolation
  • weather data
    RDF unit?
  • Roanoke Doppler

#3

I’m in. I quite like flying, and anything that has to do with it.


#4

Pick me :slight_smile:


#5

I may try to help for the dome control or some simple sensors managment (since I don’t have many of what you need/have :think:


#6

Just make sure your recovery system and communications are solid. Even the SparkFun guys got burned and lost their entire sensor package:


#7

Oooh, I’ve always wanted to do this (A thought/statement that’s gotten me in trouble more than once - witness the half-built trebuchet in my yard - too many hobbies and distractions - like work).

I might be able to help with the camera control stuff, as long as you’re not planning on using one of those nasty Nikons - wait, on second thought, go ahead and send up a Nikon, it would be a shame to waste a good Canon. :slight_smile:

Seriously, though - what are you thinking of sending up? P&S/DSLR/video/other?

On the DSLR front, I’m actually getting my head wrapped around the arduino code/libptp and taking some baby steps, but lack of time is making things go slooooow.

Also, aren’t you in NZ? Do we have to be present to win? :slight_smile:


#8

I would love to get involved but I’m to far away. So I’ll just pitch advice. Do you intend to recover the device or is it disposable?

don’t forget to post the video afterwards :slight_smile:


#9

i’m in Western Australia, i have access to a 15,000 acre farm to launch the bugger :slight_smile:

This i want to hear more of. Tell me. Now :smiley: <3 trebuchet - it would be my siege weapon of choice!

I was thinking a point and shoot, and a minature HD cam for video (can get some exceptional quality ones cheap) as well as small video cameras that are used for FPV.


#10

I’m building a small trebuchet for a local “agri-tourist” farm - the idea is to mount it on the back of a tractor carryall (roughly 6’x2’ base), and use it to entertain the guests by flinging small pumpkins, veg, and unruly children.

I was talking to the owner of the farm one day about punkin’ chunkin’ in general and trebuchets in particular when I said “I’ve always wanted to build one…” - he interrupted me by pointing at me and shouting “YOU BUILD IT, I’LL PAY FOR IT!” We’re going to see how this one does, and then decide if we want to “upsize” to a haywagon-based one - roughly 14’x8’ base. :slight_smile:

I worked on it Labor Day with my sons, and the entire time I was thinking how I could use my FEZ in that project: measure rotational speed of the arm? remote electromechanical trigger? possibly put one together with an accelerometer/GPS package and fling it to gather data? I’d be concerned about destroying the electronics. Guess I could use an Arduino instead. :slight_smile:


#11

Measurements yes, triggering a treb NO! Got to think about safety first would not want a bad bit of code or low battery to set the thing off unexpectedly. A simple mechanical release with a safety is the best way to go.


#12

use it to fling flaming 40 gallon drums of petrol/oil and cars :smiley: there is a video of some guys in the UK who did this, it is truely epic.


#13

I take it that the ballon is going to be helium filled…?


#14

Thats the usual gas for weather ballons :slight_smile:


#15

http://www.casa.gov.au/newrules/parts/101/download/nprm0009os.pdf

Page 37 on covers unmanned free balloons.

I think we would be covered as an light balloon - no more than 2m at any point in it’s flight (would have to check the physics for how it would be at it’s apex) and less than 4kg of payload.

We must inform CASA at least 24hrs before the scheduled time, as stated here:

[quote]A person must not release a light balloon outside an
approved area unless the person gives CASA the information required by
Table 101.5 at least 24 hours before the proposed release.
Penalty: ^insert units^ penalty units.
Note 1 A person can comply with this requirement by telling:
(a) if the person is an approved aviation administration
organisation — the Australian NOTAM Office; or
(b) the appropriate approved aviation administration organisation.[/quote]

Table 101.5:

[quote]The name, address and telephone number of the person who will
release the balloon (or, if several people will be involved, the
name, address and telephone number of the person who will
coordinate the release)
The date and time the release is to begin
Where it is to be carried out
The estimated size and mass of the balloons payload
If more than 1 balloon is to be released at a time, how many
balloons are to be released at the time
[/quote]

The biggest obstacles sensor wise is finding sensors which work that high/that cold. Minimum temp will be about -57c outside, and 0.16psi at 100,000ft.

For future reference:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=223-1100-1-ND
0.16-16psi pressure sensor. However it’s only 16 bit…


#16

Does the air pressure sensor really need to work at that temp? Why can’t it be inside the isolated box with tubing running out to a static port?


#17

it will still get cold. We have to keep it above -40c for the specs it lists, however it would be interesting to test it in a box of dry ice (which sublimes at -78c) and see just how cold it can work to.

Other “outside” sensors, such as light and temperature sensors need to be -60c. Another issue we need to consider is that metals will get very brittle at that sort of temperature, so some investigation into that would be good too. Would suck to have a carabiner holding the parachute on snap haha.


#18

We could just put a harness around the box for the balloon/parachute. No metal needed.

Why do we need light sensors? Is a camera not enough?


#19

we don’t need any sensors. We’re always told that light is brighter up there because the atmosphere attenuates so much of it, it would be cool to see how that changes. As with all the sensors, i and a friend of mine who is also going to be working on this, are curious to see the conditions up that high and en-route to that high.


#20

Ah, I see…

Might be a good idea to start on the isolated box before talking about sensors.