The UltraLight kit is just about ready for sale (I'm waiting for some PICAXE-28X's and to complete the directions). I've added a bunch of new stuff to the kit, including a control panel, commit tag, audio beacon, and antenna, as you can see in the picture above.
The NearSpace UltraLight is the easiest way to begin a near space program. The kit can be assembled over a weekend. All you need to complete the kit is decide on your battery and its termination (I use Anderson Powerpoles). If you have cameras, then you'll also need to select a termination method for them (I recommend Dean's micro plugs).
NearSys sells a GPS receiver kit. It is designed for flight computers like the UltraLight. The UltraLight and GPS coupled together is a complete flight computer. Build an airframe and purchase a parachute and you can begin exploring near space.
About the Flight Computer
The UltraLight digitizes four analog sensor voltages, operates three digital experiments (like geiger counters), controls two cameras, and positions two servos (the servos have their own battery). The UltraLight's audio beacon makes enough noise that you can locate the near spacecraft in tall grass or corn fields. The control panel lets you program the flight computer and download data without having to open the airframe. You can also communicate with the flight computer while launch crews are filling the balloon (perhaps to verify sensor operation prior to launch). The flight computer's Tiny Trak is also assessible through the control panel (but not while the GPS is plugged in) The control panel indicates the near spacecraft's power status and the status of the Tiny Trak (that is, when it is transmitting and when its GPS has a lock). The bright red commit tag screams a reminder to begin the mission before releasing the balloon. That way you can power up the near spacecraft and wait for a GPS lock before recording mission data (who wants a bunch of data on the ground when you're headed to 100,000 feet?).
The Onboard Tiny Trak
The APRS tracker is built right into the flight computer. The 500 mW transmitter and dipole antenna will let you track the entire mission. Since the transmitter is set for 144.390 MHz, I-Gates can put your tracking data online, allowing everyone in the world to track your flight (very useful when your chase vehicle is located in the null of the antenna).
Mission data is stored in 32kB of memory. After recovery, reprogram the flight computer to download its data right into your PICAXE Editor (with its built-in terminal program). This can be done right in the field if your want (bring your netbook along). The data is then saved as a text file and opened in Excel. You can be generating results from the mission at the post recovery lunch!
It may take another week to get the kits packed and the directions in their first draft. Meanwhikle, feel free to contact me if you have questions.
I guess it's time to start a forum!