Pegasus II

MISSION FAILED (04/03/06) - Contact was lost at launch, while sms messages were received during the first few minutes of flight the gps coords did not change suggesting a GPS error (Fear that the CF GPS card might have come loose). Most likely landed in the sea as no further sms messages were received (would expect some messages if had landed on land).

• Construction
• Launch

• Video 1
• Video 2

• Use a better balloon e.g. 1200g balloon to push above 100,000ft
• Replacing the downwards camera with a digital video camera (cheap from ebay)
• Temperature sensors - inside and outside payload
• New container - use the dry ice containers from university pathology department - they are much easier to work with (a good size and thick.)
• More complicated software - allow commands to be sent by text message, the gumstix using gnokii checks the phone's text message inbox and reads the latest message - examples of commands are - dial up internet and email gps.log and allow ssh login, reduce the amount of text messages say to every 5 mins (once we have a lock there is no need for as many messages).
• The tracking system showed its flexibility and will be kept pretty much unchanged.

• Gumstix CFstix pack - £106 ($186) before VAT and shipping
• gumstix connex 400
• waysmall STUART
• cfstix

Option 1

• CF to serial adapter £97.95 (inc. VAT)
• 3145 - Computer Temperature Data Logger £16.95 (inc. VAT)
• 2 x DS18S20 (one included with logger) £3.95 (inc. VAT)
• Serial GPS unit (from Pegasus I) (connected to waysmall serial port)
• Nokia 5110 phone (connected to waysmall serial port)
• Total = £118.85

Option 2

• CF GPS unit -£84.95 (inc. VAT)
• 3145 - Computer Temperature Data Logger (connected to waysmall serial port) £16.95
• 2 x DS18S20 £3.95
• Nokia 5110 phone (connected to waysmall serial port)
• Total = £105.85

Option 3

• USB 1.1 Host Adapter CF Card here £105
• PhidgetInterfaceKit 8/8/8 from here (connected by usb to the host adapter card) £74.91 (inc. VAT)
• Phidget Pressure Sensor (suprisingly expensive) - £37.46 (inc. VAT)
• 2x Phidget Temperature Sensors (One for inside the payload and one for external environment) - £8.24 (inc. VAT)
• Humidity Sensor (suprisingly expensive) - £52.44 (inc. VAT)
• Serial GPS unit (from Pegasus I) (connected to waysmall serial port)
• Nokia 5110 phone (connected to waysmall serial port)
• Total = £196.39 (just with temp. sensors)

Gone ahead and ordered:

• gumstix connex 200 (felt i didn't need that much processing power)
• gumstix cfstix expansion board
• waysmall STUART expansion board (has 2 serial ports)

Think i'm going to take option 2 as its possible to get the cf gps units for under £50 and so the overall costs will be much lower

My gumstix arrived today all the way from california - already fought with the dhcp server on my desktop and manged to login over usbnet (serial console was being weird so I gave up rather rapidly on that approach). Changed it now to a static address which allows me to easily login now.

Now the plan is to gather all the other remaining parts though I reckon i'm going to hold off till after christmas before hitting ebay - I reckon things might be a little cheaper and can't be bothered for things to get lost in the crazy christmas postal service.

Here is a list of things required (i'll say when I've got hold of each part)

• 1000g latex weather balloon -
• 36” parachute - got, from pegasus I
• Nylon cord - got
• polystyrene container -
• gumstix connex 200 - got
• cfstix expansion board - got
• waysmall STUART expansion board - got
• CF GPS unit - got
• Nokia 5110 - got, from pegasus I
• Nokia data cable - got
• serial data logger with 2 temperature sensors -
• 3 cameras around 3MP (to be arranged to create overlapping pictures and therefore a panoramic view)
• cheap digital video camera - ordered
• 3 uv lenses

Now christmas is over have ordered a CF GPS and a Nokia data cable from ebay - waiting for them to arrive before I start work.

Right - so gps and cable have arrived - managed to get the gps working through some terrible kernel hacking (will explain more in the final write up! - something to do with namespace clashed) so now gps works through ttyS0 and the serial ports are ttySA0. Also put on gpsd and gpslogger so everything is in place that side and ordered an external antenna to allow for better reception.

Now onto getting gnokii to work - is going to be slightly harder due to the requirement of the extra lines of the serial port to power the circuitry in the cable itself (converts from rs232 to TTL). Perhaps its time to start getting everything else - anyone have a 1000g balloon lying around as kaymont aren't replying to my emails!

Here is a page explaining the pxa and 8250 namespace clash and how i solved it, hope it helps!

Been testing the gps - even without the external antenna it works well in the car so that looks good. Gnokii looks like its going to be a bit more work. Have decided to upgrade to a nokia 6310i (have one with a broken screen) tested it on my mac so it works well with gnokii - now time for me to sort out the serial ports.

Managed to get the gumstix connecting to my nokia 6310i (with the broken screen). Was having major issues as I had to power the conversion circuitry in the data cable (usually provided by RTS and DTR from the serial port). The gumstixs serial ports are actually only Txd, Rxd and GND so i somehow had to find an alternative. Firstly i used the adjacent serial port changing the outputs to GPIOs and that worked. Then I soldered some wires onto the I/O pads on the base of the waysmall and linked them up and it worked! Now a matter of getting hold of male DB9 socket to attach all these stray wires to.

This page is beginning to get a bit messy so I'm going to split it into two - continue making progress updates (and no phatmonkey i'm not going to switch to a blog - i'm far to lazy and enjoy pretending that I'm hacker by handcoding my html) and also begin compiling the final report.

Also ordered the cheapest digital video camera possible off ebay - looking forward to seeing how awful it is. Also bidding for 2 tinytag temperature loggers - if i manage to get them i won't need the serial data logger as they record themselves. Which leaves me with a free serial port (well only Rxd, Txd and GND at rs232 levels) any ideas email me at jacoxon@googlemail.com

Have orderd a geiger counter off ebay to be hacked up and attached to the gumstix (either through the spare serial port of a gpio). It produces clicks which could quite easily be interfaced to be measured and then recorded. Hehe, should be fun!

Have now recieved a 1200grm and a 200grm totex balloon from the British Antarctic Survey (i got it through the Atmospheric Chemistry Department - BAS is based in the Cambridge and obviously Antarctica). With that now I reckon I'll be able to launch within a month and a half.

Also the digital video camera has arrived (got it off ebay) it should be sufficent for its job - to face down and video the ascent and descent (will be very useful to see how much spin the payload experiences).

Now looking into getting hold of the rest of the parts and then to start constructing the payload itself.

Lots has happened since the last update! I've sent off my permission application to the CAA for a launch window for March. I reckon my first attempt (weather permitting) will be on Sat. 4th March from my college sports pitches (I hope that they aren't being used!) - hopefully the CAA will get back soon with how thats going!

Also i've put together the serial temp. sensor kit and it works off my usb→serial - now to make it communicate with the gumstix (shouldn't be too difficuly as it only has 3 lines - DTR, RxD and GND). Decided not to go with the tinytag sensors as they would require me getting a cable and the software - I'm sure they'll come in useful one day!

Now the geiger counter - got this off ebay, its more of a russian personal dosemeter. Opened it up to find the most rubbish engineering ever with some insane methods of doing things such as the use of what looks like a nixie tube to show the flashes - surely there are better ways. Have totally given up on trying to sync it - not to much of a loss though. As has been suggested I'm still going to go ahead and put some unexposed film on the top of the payload undercover and see if it encounters any high energy radiation. Simple yet quite effective.

Am now working on the various jobs left to do such as find a payload container - any ideas please email me!!!!!! jacoxon@googlemail.com

Just a quick update! Still nothing back from the CAA but not in too much of a rush, ordered lithium batteries, found enough polystyrene and have recieved the camera. Plan to do some construction today (its 2.47 am so at a more reasonable hour) so might post some pictures.

Pegasus II has sadly been lost, more then likely into the North Sea - there are many reasons I can think of (and lessons to be learnt):

• Winds were totally in the wrong direction - they were blowing SE towards the sea, considering we were using a 1200g balloon with a light payload it was going to go a long way! * The balloon was too big - jumping from 200g to 1200g with a payload of approximately the same weight was perhaps a little ambitious!
• Too complicated - I tryed to fit to many things on to the payload - they should have been launched on seperate launches. This also meant that I was worry about interfacing the various experiments and not paying enough attention to the vital gps/phone system
• Too rushed - I left it to late to finalise the payload which meant not sleeping the night before in an attempt to get it finished and actually working on it as the balloon was being inflated.

There is of course the chance that someone will find it and contact me which would be nice

Of course this isn't going to stop the Pegasus Project - Bring on Pegasus III