Thanks Dan, for your comments. My son rattles off questions just about non-stop. I make every attempt to answer them without being condescending, and with as much technical input as I feel he can take. I love it, but his mum can't deal with the barrage of questions!
Maybe its the answers she really can't deal with,
In reality, we don't need to retrieve the plane. All it needs is a transmitter, power supply and one or two sensors. The sensors could just be a thermometer - we really just want to know if it is burning up or not in the main instance. If it burns up, we have a result. If it doesn't, we can initially assume it has survived re-entry.
Other sensors could be an accellerometer and something to gauge the dimensional stability of the craft to determine if it is keeping its shape or crumpling. The accellerometer could be determined by monitoring the transmission through GPS, or something. None of these sensors as components are very big, and an appropriately designed and size of paper plane would not be difficult to build.
I happen to recall earlier this year about an Australian father and son team who have started a business of light weight rockets, and deploying sub-orbital and low orbit science payloads. Some of these were also something like 'paper planes' that had sensors on them, some type of 'nano-bots', that fluttered down. Reason I mention this is the 'paper plane' notion is really not that crazy and pointless.
If I only could remember the details of this father and son team. I think they are in South Australia. I wish I had paid more attention to the radio that day.