The trans-Atlantic balloon flight of the Spirit of Knoxville V is set to launch April 5 at 2000 EDT (0000 UTC April 6). The balloon, designed to stay aloft for more than 24 hours, will be inserted into the current jet stream at normal flight altitudes of 30,000-40,000 feet.

This will take the balloon into Europe over the UK and France at around 40 hours into the flight if all goes well. Using radio frequencies, the balloon transmits data detailing its current location, distance traveled, speed, height and health of the balloon. Last month, the Spirit of Knoxville IV made two-thirds of its journey and crossed the tectonic plate to Europe; organizers hoped the balloon would make to Europe, but after 40 hours and 3300 miles, the balloon lost altitude and went into the ocean as it neared Ireland.

The balloon's payload consists of hand-made computers and radios along with a GPS and self-authored software. The onboard computer gathers information from the GPS like altitude, speed and temperature; the computer then determines whether it needs to drop weight to maintain its altitude and sends this information, via Amateur Radio frequencies, to volunteers around the globe. Track the mission live (the live status page will only become active at launch).
See the Spirit of Knoxville Web page for more information.

[ARRL Letter]