An accident during prelaunch testing has delayed the test flight of the Cosmos 1, which was developed by Babakin Space Center in Moscow for The Planetary Society of Pasadena, Calif. The solar sail remains scheduled for late September or early October. The incident occurred at the Severmosk launch port and preparation area outside Murmansk, Russia. According to reports, the pyrotechnic systems that are responsible for inflating the sail were triggered while the craft was being mounted for testing. Cosmos 1 will demonstrate the feasibility of propulsion by the pressure of sunlight. It features a 600-m2 sail of 5-µm-thick aluminized Mylar.