RAY: This is from the wonderful world of space travel. This puzzler was sent in by Dave Foster. I actually had to obfuscate a little, but here it is:

In the early '60s, NASA was sending electronic gear into outer space on unmanned missions. They'd already sent a guy into space but they wanted to make sure that if they were going to send people up for longer flights, that they had a chance of surviving. They were sending this electronic gear up to test a variety of things like radiation exposure, and so on.

The equipment kept failing, but they couldn't figure out why. Finally, someone determined that the circuits were overheating, so they installed a fan to cool off the devices.

But the problems persisted. Why?