Repaired solar sail now ready for test launch

Posted: June 13, 2001

A suborbital demonstration flight of a solar sail is back on track for launch after a botched test damaged the craft. With repairs completed, the mission is expected to occur this summer aboard a Russian Volna rocket launched from a submarine in the Barents Sea.

Solar sail
Illustration of solar sail test flight. Photo: Babakin Space Center/The Planetary Society
Originally set to fly on April 26, the Cosmos 1 test spacecraft was damaged during pre-flight testing on April 9. As officials conducted a test on the craft's electrical systems, a short circuit caused the re-entry sequence to begin, which includes the deployment of the inflatable heat shield and the firing of pyrotechnics to jettison non-essential components from the core re-entry vehicle.

The electronics of the spacecraft remained undamaged, but various cables were snapped and parts of the sail platform were bent.

The craft was immediately shipped from the launch site facility back to the Babakin Space Center in Moscow for repairs. Those repairs included the replacement of the two blades that comprise the solar sail, as well as other damaged parts of the vehicle.

The Planetary Society, a sponsor the Cosmos 1 missions along with Cosmos Studios, reports that the new components have been successfully retested and that the platform has been transported back to the home port of the submarine that will launch the mission, located in Severmosk, Russia. With that, the launch can now proceed as far as the payload is concerned.

But the Russian navy, which is in charge of the launch operations, has yet to approve a launch date for the mission. Officials say that a June launch date out of the question, and that a mid-July launch is much more likely. They say that a new date will probably be agreed upon by the end of this month.

Once the suborbital mission launches, the flight will last almost 32 minutes, beginning with a launch in the Barents Sea, and ending with a touchdown on the Kamchatka peninsula. Engineers will be focusing their attention on the deployment of the two solar sail blades, but because there will be no live telemetry from the sail, they will have to wait until film of the deployment is returned inside the re-entry vehicle.

In the midst of the delays of the suborbital test flight, the primary orbital mission is still set for launch late this year, pending the results of the suborbital flight. It will launch aboard another Volna rocket to an orbit around 850 kilometers high, where it will deploy its eight solar sail blades to demonstrate solar sailing for the first time. Project officials hope that tracking stations will be able to detect gradual altitude and velocity changes, verifying the success of the mission.

Solar sails work by utilizing light pressure to propel itself and to change its attitude. Studies have shown that the Sun's useful light energy for solar sails dissipates by the time it reaches the orbit of Jupiter, so future missions would have to rely on laser light for propulsion after they pass that point.