While solar sail project leaders cling to diminishing hope that their tiny spacecraft achieved orbit yesterday, Russian launch officials say the modified booster rocket malfunctioned and crashed.

Cosmos 1 was launched from a submarine aboard a Volna rocket, as shown in this artist's concept. Credit: Michael Carroll, The Planetary Society

"In the past twenty-four hours, the Russian space agency (RKA) has made a tentative conclusion that the Volna rocket carrying Cosmos 1 failed during the firing of the first stage. This would mean that Cosmos 1 is lost," The Planetary Society, the solar sail's organizer, said in a statement issued at 1730 GMT (1:30 p.m. EDT) today.

"While it is likely that this conclusion is correct, there are some inconsistent indications from information received from other sources. The Cosmos 1 team observed what appear to be signals, that looks like they are from the spacecraft when it was over the first three ground stations and some Doppler data over one of these stations. This might indicate that Cosmos 1 made it into orbit, but probably a lower one than intended."

The Volna rocket -- a converted ballistic missile -- blasted out of its launch tube aboard the Borisoglebsk at 1946 GMT (3:46 p.m. EDT) Tuesday. The Russian Navy submarine was stationed underwater in the Barents Sea offshore Russia's northern coast.

American scientists anxiously awaited news that their solar sail had been delivered into the desired 500-mile orbit around the planet. But tracking stations positioned to hear transmissions from the craft originally reported hearing nothing.

Hours later, The Planetary Society announced that its team had uncovered what were believed to be weak signals in recorded data from the sites at Petropavlovsk on the Kamchatka peninsula in far eastern Russia and on the island of Majuro in the Pacific's Marshall Islands. Even more encouraging was possible signals received via Panska Ves in the Czech Republic near the end of the first orbit, suggesting the spacecraft had reach some kind of sustainable altitude and not simply re-entered the atmosphere on a sub-orbital trajectory.

However, Russian media reports quoted naval sources as saying the Volna's liquid-fueled first stage engine stopped firing too soon, causing a failure to reach orbit.

The conflict in data between the rocket team saying the booster misfired and the Cosmos 1 team still thinking the sail was in space was further complicated by U.S. military's Strategic Command space tracking network's unsuccessful attempts to spot the sail in orbit.

So is Cosmos 1 truly circling the Earth today?

"The project team now considers this to be a very small probability," this afternoon's Planetary Society statement acknowledges.

However, the scientists aren't ready to give up completely despite the odds stacked against them. Efforts to contact and track the spacecraft continue because of the "slim chance" the craft is somewhere in space, just not the intended orbit.

"We are working with U.S. Strategic Command to provide additional information in a day or so," The Planetary Society statement said.

"If the spacecraft made it to orbit, its autonomous program might be working, and after four days the sails could automatically deploy. While the chances of this are very, very small, we still encourage optical observers to see if the sail can be seen after that time."