Hellschreiber balloon launch

James M6JCX brings news of a Cambridge balloon launch at 1800 UT on Friday, July 9, that will carry an RTTY FSK beacon on 434.075 MHz and a CW and Hellschreiber (Feld-Hell) beacon on 434.070 MHz.

The use of Hellshcreiber is unusual on a balloon launch and this is possibly a first. Hellschreiber is potentially a very good format since it relies on the human brain to decode the characters from the pixels displayed on the PC screen.
The human brain can still interpret characters even under conditions of heavy interference.

Hellschreiber can be decoded by fldigi software, however, currently it is not included in dl-fldigi but will be in the future.

James M6JCX writes:

Finally have got round to the 5th launch in the BallastHalo series, which have been testing latex pinhole floaters and also ballast tanks in anticipation of a future trans-atlantic launch. BH5 consists of a main flight computer downlinking RTTY, a peristaltic pump, ballast tank and a backup beacon.

The plan is to launch BH5 from Churchill College, Cambridge at 18:00UTC (19:00BST) aiming for an ascent rate of between 2 and 3m/s.

Sunset on the ground is at 20:16(UTC) which means that at altitude sunset will be at ~21:00. Hopefully at sunset the balloons ascent rate will drop and begin to float. When this float is detected the flight computer will drop some ballast which should break the float - whether it re-establishes float slightly higher is something we'll find out!

With the current flight predictions it'll stay with in the UK, if we manage to float for a small period of time the payload 'should' land on solid ground (as it'll float inland), if it doesn't float then there is a high chance of a sea landing. The key however is that the ballast tanks get tested at altitude, even a small drop will be counted as a success. This payload has survived 2 Channel crossings visiting France and the Netherlands so it might well be a fitting end.

Lots more information can be found on my webpage:
http://www.pegasushabproject.org.uk/wiki/doku.php/
missions:ballasthalo:ballasthalo5

Tracking is very welcome especially in the East of England, potentially if we can establish float then it could float all night however the ballast drops could disturb this. There is no onboard storage so the more data we can gather over the radio the better.
As usual the best way to track is using dl-fldigi both old and new versions - more info can be found on the UKHAS wiki http://ukhas.org.uk/guides:tracking_guide In dl-fldigi select 'atlas' as the payload to track.

Main Downlink:

* 434.075MHz RTTY 50 baud, ASCII-8, 350 shift, no parity, 1.5 stop bits

* Sample String:
$$ATLAS,0,12:44:33,51.4982,-0.0529,20064,3,0.0;10;1; 31;27;79;500;0*6E

* $$Callsign,Cycle_Count,HH:MM:SS,Latitude, Longitude, Altitude, Number of Sats, Ascent Rate, At Float, Float Time, Internal Temp, External Temp, Light, Ballast, Ballast Mode*Checksum (XOR)

Backup Beacon
* 434.070MHz
* CW 14WPM
* Hellschreiber (Feld-Hell)
* 3 strings looped every 10 minutes

Follow the flight @ http://spacenear.us/tracker/
Follow progress on twitter: http://twitter.com/jamescoxon
Chat on #highaltitude on irc.freenode.net

Thanks

James Coxon, M6JCX
http://www.pegasushabproject.org.uk/

FLDIGI
http://www.w1hkj.com/Fldigi.html

DL-FLDIGI
http://code.google.com/p/dl-fldigi/

FELD-HELL Hellschreiber
http://sites.google.com/site/feldhellclub/