The whereabouts of the re-entry vehicle from Thursday evening's launch of a first-of-a-kind solar sail test flight were unknown Friday, after recovery forces failed to find the craft in Russia's far east as planned. The capsule contains the only record of the sail deployment experiment.

Launch of the Volna rocket carrying the Cosmos 1 solar sail demonstrator for the Planetary Society and Cosmos Studios occurred from the Russian submarine Borisoglebsk in the Barents Sea at 0033 GMT (8:33 p.m. EDT Thursday). The launch was timed to give recovery officials in the landing area on Kamchatka peninsula an optimum amount of time in daylight hours to find and retrieve the re-entry capsule, which contained two video cameras that were to record the event.

Those cameras were crucial to the mission because they were the only source available for officials to learn the outcome of the deployment test of the twin solar sail blades.

Illustration of solar sail test flight. Photo: Babakin Space Center/The Planetary Society

The vehicle was to plunge back into the atmosphere inside an inflatable re-entry shield, which was also designed to cushion the capsule during landing.

Radar tracking stations across Russia confirmed that the rocket did place the solar sail spacecraft on the expected suborbital trajectory, The Planetary Society reported.

After the 31-minute flight was over, the capsule's beacon, GPS unit, and COSPAS-SARSAT search-and-rescue equipment were to send signals to both ground and airborne recovery teams. However, as of late Friday, none had been received.

Search teams were dispatched Thursday night, but their attempts have turned up nothing so far. Officials say that those crews continue to look for the vehicle.

"We had hoped to get a signal from the re-entry capsule immediately -- but that did not happen. We still hope to find it and recover data within a few days if the capsule landed safely," Planetary Society Executive Director Dr. Louis Friedman said.

In addition to that issue, there is also some speculation that the re-entry capsule and the solar sail itself, which was not to return to Earth, may not have separated properly from the third stage of the Volna rocket. But that has not been confirmed, The Planetary Society said in a statement.

"We don't know what happened yet," said Viktor Kudryashov, the Cosmos 1 project manager at Babakin Space Center, the prime contractor for the mission. "We will have to examine all data next week."

Friedman later tried to put a positive spin on the apparently bleak situation, saying: "Whatever the final outcome, this mission -- the launch from the submarine and that cooperation with our partners in Russia -- is a great step forward and accomplishment for The Planetary Society and Cosmos Studios. The flight is already a success in two areas: we are the first space interest group to send a mission into space, and a brand new media company, Cosmos Studios, sponsored the launch."

After the Volna rocket's three stages finished their jobs of placing the payload on its proper suborbital trajectory, the spacecraft module was expected to separate and the inflatable re-entry shield was to have deployed itself shortly thereafter.

The two solar sail blades included in the Cosmos 1 test craft were to have begun their deployment sequence at a little under 10 minutes into flight at an altitude of 412 kilometers. The twin cameras were also expected to begin rolling at that point.

The deployment sequence was expected to last around two minutes, followed by a long coast period after which the two blades were to have been jettisoned in preparation for re-entry.

The re-entry sequence began at an altitude of 100 kilometers and at a point about 17 minutes after launch.

After nearly 15 minutes of immense heat and friction, the re-entry capsule, cushioned by air bags mounted on the joint German/Russian inflatable re-entry shield, was expected to land in Kamchatka.

Officials tracked the spacecraft throughout the duration of its flight using Russian radar systems that are routinely used on Russian missile tests and space launches. The last telemetry from the vehicle was received shortly before re-entry, when a communications "blackout" was expected.

If the vehicle is found, it will likely take at least two or three days -- or even up to a week -- to analyze the video recorded from the on-board cameras. Because of the lack of live telemetry from the sail itself during the mission, only then will we know the outcome of the test.

The Cosmos 1 primary mission, with a full complement of eight solar sail blades, is scheduled to be launched into Earth orbit late this year using the same type of rocket that was used on the test flight. That launch date is contingent on the results from this flight.

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.