Solar sail experiment lost due to launcher problem

Posted: July 21, 2001

Officials analyzing data from this week's test flight of a solar sail demonstrator have confirmed that the third stage of the Volna rocket failed to separate from the spacecraft. That left the inflatable re-entry shield and the two solar sail blades unable to deploy, dooming the mission.

The joint German-Russian inflatable re-entry shield was to have deployed itself moments after third stage separation, followed shortly thereafter by the beginning of the deployment sequence for the two solar sail blades, which was to have been filmed by two cameras that were supposed to return to Earth aboard the re-entry capsule.

Solar sail
Illustration of solar sail test flight. Photo: Babakin Space Center/The Planetary Society
The Planetary Society, which sponsored the flight along with Cosmos Studios, said in a statement that engineers continue to examine telemetry from the vehicle "to determine exactly what happened and why."

An initial finding in the investigation shows that the command to separate the third stage from the spacecraft was overridden because powerful variations were detected in the rocket stage. The Volna rocket's systems were programmed to override the separation command if such a situation occurred.

But Planetary Society officials say that those variations would not have affected the solar sail deployment test or any other part of the flight. "This possibility is being examined further," The Planetary Society said in a statement.

A recovery team near the landing site on Kamchatka peninsula reportedly saw the fiery re-entry of the spacecraft, with the Volna's third stage apparently still attached. The remnants of the craft are believed to have impacted near the expected touchdown location in Kamchatka.

Search teams will continue to look for the likely demolished capsule, reports say.

It is unclear as to exactly what affect these developments will have on the orbital flight of the Cosmos 1 solar sail, which is also planned to launch aboard a submarine-launched Volna rocket. That launch was previously scheduled for late this year.

However, Bruce Murray, President of The Planetary Society, is still hopeful for a launch later this year. "I am quite impressed with how well the US-Russian team, involving non-profit and commercial organizations, and relying heavily on Russian military and civilian organizational support, worked together effectively and harmoniously in this test. I am optimistic that we can keep on schedule to launch Cosmos 1, the first solar sail spacecraft, later this year," he said.

Solar sails work by using light pressure from stars -- the Sun in the case of Cosmos 1 -- or lasers to change their velocity, orbital energy, and attitude. Spacecraft with solar sails need little or no fuel to maneuver.