Artist's impression of a solar sail. Photo: Michael Carroll/The Planetary Society.

The Planetary Society disclosed Wednesday that it's plans to launch a solar sail demonstration satellite later this month would be delayed indefinitely due to a testing accident that damaged the spacecraft.

The sub-orbital test flight of the so-called Cosmos 1 craft was scheduled to launch from a Russian Delta III Class submarine in the Barents Sea on April 26.

Officials said the accident occurred during a ground test at Severmosk, the launch port and preparation area near Murmansk, Russia. The test craft arrived there from the Babakin Space Center located near Moscow. The Babakin Center is developing the craft for The Planetary Society.

Preliminary information indicates that the accident occurred when the actual operation sequence of the spacecraft was initiated while the craft was mounted for testing.

"The extent of damage is unknown at this time," said Dr. Louis Friedman, Executive Director of The Planetary Society and Project Director of Cosmos 1. "Though we are disappointed that this accident has caused a delay, we recognize that this is what tests are for. This test occurred on the ground and with our test vehicle and in no way derails our program. In fact, it could help us to avoid more costly problems in the future."

The spacecraft will be returned to the Babakin Space Center where it will undergo checks, repairs, re-assembly and tests. The test flight will then be re-scheduled.

Artist's conception of the sub-launched rocket. Photo: Michael Carroll/The Planetary Society.

Two flights of the solar sail design were slated to occur this year -- the suborbital flight in April and an orbital launch in the October to December timeframe.

The suborbital flight will feature the deployment of two solar sail blades to test deployment techniques. An inflatable re-entry shield will be used to return film from cameras aboard the sail after the half-hour flight ends with a landing on the Kamchatka peninsula.

The primary orbital flight will see a full solar sail assembly of eight blades that make up an area of around 600 square meters. The structure is composed mainly of aluminized mylar.