Apple - Science and Technology - Flying High with a Solar-Powered Wing

Powered by the sun and controlled by Power Macs, the ultralightweight Helios aircraft shattered the world altitude record in August 2001 when the remotely-piloted vehicle climbed to more than 96,500 feet (29,421 m.) - three times higher than most commercial jets - in a test flight over Hawaii.

The last time I mentioned Helios was the BBC News | SCI/TECH | Solar craft sets altitude record post which had personal interest for me:

Had the weather been better in Kauai whilst we were there then Helios may well have been launched during our vacation. The maiden flight of Helios took place the week before we got to Kauai.