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OZ HAB

Near Space Project

Ozhab2 – The New Project for 2018

Since the launch and unsuccessful recovery of Ozhab1, I’ve always planned to reattempt another launch. However time and more important tasks seem to get in the way. However 2018 brings on many new challenges., so why not throw the construction of Ozhab2 into the mix. Though I still hope Ozhab1 will be found  (slim chance), I’ve certainly learnt a lot and had a lot of fun building, launching and tracking it.

Construction of Ozhab2 has now commenced with the 2m – VHF APRS module arriving a week ago. The module is the same Radiometrix HX-1 used in my previous launch and I was very happy with it.

For Ozhab2, I’m not trying to reinvent the wheel, so will base my tracker off the Trackunio project code for Arduino. I won’t be using the Trackunio Shield as that wouldn’t be as much fun,

APRS looks to be transmitting already, but I haven’t tested a decode yet. A little more to go yet.

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Testing Ublox GPS Module

Purchased a couple of Ublox GPS M8N modules recently and thought they may have been faulty as my Ardunino Nano wasn’t receiving any data.

So I thought I would share how I tested my module, in case it’s of use for anyone else.

First you need to obtain a few items and download the Ublox software :-

Ublox GPS Module (I usUblox GPS Moduleed a M8N which is on a GPSV3 board for this test)

 

 

 

 

Serial to USB (I used a YP-05 FTDI Module)FTDI

 

 

 

Use Connector Wire to hook the GPS Module and FTDI board together. My GPS module works with both 3.3v and 5v, just ensure you send the right voltage.

Connect the VCC -> VCC  and GND -> GND  , then ensure TX –>   RX   and the RX -> TX
gpd-ftdi

Before I connect the USB cable I like to check in my Windows Device manager to see what is connected under the “ports (COM & LPT)” that way you should be able to identify what COM port your FTDI will be on.
After connecting the USB cable, i see the following appear. commportd This indicates that my FTDI will be connected to COM14.

If you don’t already have the UBlox U-Center software you will need to download and install it. Ublox – U-Center

commportucenLaunch U-Center and set the Port and Baud Rate via the Receiver Menu.

 

Usually the Baudrate is 9600 by default, but you may need to try other speeds if you don’t have any luck.

You may also need to change the GPS type under the generation menu.

Within U-Center you can enable various windows to show you the information coming out of the module. The simplest to understand appear under View – Docking Windows. Just enable some of them to confirm your getting data.

dockingucentr

If you have connected everything correctly you should start seeing some information appear.  You should see several satellites and their signal strength, you should also see a sat fix status.
Remember if you’re indoors, you may not get the best signal.

If no data is received, check your settings and connections.

This should allow for a basic test to confirm the GPS Module is working. Take care if your trying to change any settings on the module as you can alter the modules characteristics which may not suit your project.

 

 

 

Launch video and data of OZHAB01

Here’s the video of OZHAB01 being launched from Barmedman  NSW as well as other data I have collated so far

Unfortunately I have not yet recovered the payload of OZHAB01 so I am unable to provide any of the on board collected data. However I do have some flight data that was collected via APRS and the RTTY transmitter which gives a good indication of the flight progress.
The APRS was being received by digipeaters around 1000m and continued to have contact until it burst about 31000m. APRS Google Earth KML OZHAB01

aprs-altitude
Elevation Profile
aprs-flight
Flight from Launch until bursting

The RTTY was decoded on my laptop as I chased the balloon and followed the same path as the APRS. I did loose signal a few times as it was climbing to its burst altitude. RAW KML of RTTY Flight for Google Earth

rtty-collected-data-kml

Post Flight thoughts for next time

  • Ensure I pack a highly directional antenna to locate the payload.
    • Something with variable attenuation would be great.
  • Use a weight instead of digital scales to determine correct lift and helium dosage.
    • The digital scales were difficult to read as the wind blew the balloon around, which lead to less helium in the balloon and a slower ascent.
  • Cut balloon away when approaching max altitude to ensure a cleaner descent.
    • As I haven’t recovered payload yet, I don’t know how much balloon was intact and this could have impeded the parachute
  • Don’t forget the tarp next time.
    • Blankets worked , but were too small
  • Improve my APRS decode.
    • APRS was decoding sporadically.
    • I didn’t have an app installed that would upload the APRS data to the web

Still tracking

Flight is taking a little longer then expected but trackers are still transmitting.  Phew Should be reaching bursting altitude soon.

I was getting concerned that it wasn’t going to make the predicted turn back west and keep heading towards the east. But it saw my mountain and decided to make a turn. 🙂

turning.JPG
Turning back at Mount David

5 mins , tracker online

Tracking OK, before launch, if I continue to have signal the map should update.
look for VK2HEK.

https://tracker.habhub.org
or, if APRS is working
http://aprs.fi/#!mt=roadmap&z=12&call=a%2FVK2HEK-9&timerange=3600&tail=3600

tracking.JPG

15min to launch of ozhab01

Longest 15mins ever. Trackers ready but am I. 

Launch preps underway

The launch preps are well underway.

Launch preps

OzHAB1 is Go for launch

After a long wait, the day has finally come where I hope to have a successful launch of my first ever Arduino based High Altitude Balloon project.

My launch approval has been granted through CASA and my NOTAM has been issued for Wednesday morning 9am / Tue 10pm UTC.

notam.jpg

The approval process was a lot easier than I had expected. I ensured that I provided all the information required from the regulations for a light balloon and the rest was easy.

I’m currently camped out at the launch site in Barmedman NSW where it must be at least 30 degrees C, so its going to be a hot night. Not going to make sleep easy when I’m rattling all the things of forgotten to bring through my head.

pred.JPG

The predicted flight looks straight forward and as long the transmitters hold out, I should get some good results.

I’ll have a APRS tx on 145.175 , and RTTY on 433Mhz.
As long as I have mobile reception I should be able to upload to https://tracker.habhub.org/  or http://aprs.fi

 

 

Connecting chute and payload

I’ve reached a point where I am now securing the payload to the tie lines running up towards the chute and balloon. I want to have as much of the securing done prior to the launch day so I save time and potential last minute problems.

I have seen some launches where the balloon is tied in line at the top of the chute as well as others where it is tied below. My initial though is that the payload is going to weight as much as the balloon itself. If upon bursting the remnants  weigh the same or maybe slightly more, then the payload, its possible that the balloon will pull the chute upside down preventing it from opening.

chute-setup
Parachute with balloon line clipped in

I have placed a mini carabiner similar to that used to hold your keys onto the line running to the chute. I’m hoping that when the balloon bursts it will fall causing the carabiner to slide down towards the payload leaving the chute clear to open.  I just need to ensure that the chute doesn’t tangle with the balloon line.

Both methods seem to have been successful for other people’s launches but I feel that the 2nd method will allow for a better chance of recovery.

payload-test
Testing out payload lines

The lines around the payload are  taking shape with some test lines taped to the sides. I still need to load the items into the payload and balance out and finally secure with more tape.

 

I will be placing the trackers in a separate box, so need to ensure that the antenna doesn’t become tangled or interfered with.

I am also trialing some fishing swivels that have a hook clip at one end. They seem to allow the rope to fit onto the swivel and are smaller then the small carabiners.

swivels
Fishing Swivel and Carabiner

 

 

I have had to use two of these specific types as the clipped end connects nicely to the rope whilst the eyelet on the swivel would require thinner rope.

payloadI am still working on the balancing of the payload but the below shots give you an indication of what it looks like so far.

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