The idea is that it carries a GPS and a steerable parachute, so it steers itself back to the launch pad on the way down.
An introduction to the project is in the PowerPoint presentation below. Fair warning: It’s 60 Mbytes.
Update January 2010: I’ve posted all the hardware design and source code for the “Rev 3” hardware on this site. The main index to the series of posts is here.
Update March 2010: I’ve replaced the presentation with a slightly updated version that I presented at NARCON 2010. It discusses a little about the “Rev 4” hardware, based on the 32-bit PIC32 MCU, toward the end. Download all 3 files (and put them in the same folder) if you want the Google Earth links to work.
2010-03 NARCON Presentation.ppt (PowerPoint file)
1004_f2_pressure.kml (Google Earth .KML file, flight of 2008-10-04)
1101f2_pressure.kml (Google Earth .KML file, flight of 2008-11-01)
If PowerPoint is an issue, here’s a PDF version of the slides (15 MB):