A privately funded spacecraft launched from a Russian submarine and intended to deploy a solar sail into Earth's orbit was lost to controllers shortly after takeoff, but late Tuesday engineers tracking Cosmos 1 said the craft might have been found.
Engineers in Moscow and Pasadena poring through reams of tracking data said eight hours after the launch, which took place in the Barents Sea, that they might have detected faint signals from the craft indicating that it was in space, but not in its intended orbit.
Data from four separate tracking stations -- buried under a large amount of background noise -- "appears to indicate a spacecraft signal," the Planetary Society said in a late-night statement released in Pasadena, where the society is based.
"It seems like it is in orbit," said David Betts, director of projects for the society. "The most consistent story is that it made its orbit and is transmitting. That's great news."
Cosmos 1 -- a $4-million spacecraft powered only by the sun's rays -- is regarded by its makers as the first practical attempt to engineer a class of space vehicle that could reach other planets and other stars using rocket power only to attain Earth orbit. Powered by photons emitted by the sun, it could theoretically attain speeds far greater than those of the space shuttle.
The apparent reacquisition of the spacecraft was the first bit of good news for the assembled members of the society, who had grown increasingly despondent as the day wore on without any sign of the craft from the tracking stations. A search by U.S. Strategic Command government radar failed to find any trace of the craft. But they were looking for it in the expected orbit, and that's probably why they didn't find it, Betts said.
"It's probably in a lower orbit, which is why the signals are so weak," he added.
The tracking stations in Petropavlovsk and the Kamchatka Peninsula in Russia, Majuro in the Marshall Islands and Panska Ves in the Czech Republic are part of the Russian space network. The mission is being controlled in Moscow, with a secondary control center in a remodeled carriage house near the society's headquarters in Pasadena.
Theorists and science-fiction writers have long imagined a type of spacecraft that would be swept through the cosmos by the sun's rays as they were reflected on broad panels or wings. The spaceship would steadily accelerate as it journeyed deep into space, venturing into the outer solar system or possibly other stars. Among the strongest proponents for such a spacecraft was the late astronomer Carl Sagan.
Cosmos 1 is intended to test the theory that photons, or packets of light emitted by the sun, could propel the spacecraft to a higher and higher orbit before it eventually fell back to earth. After being lofted into its initial orbit by a converted intercontinental ballistic missile, Cosmos 1 was designed to unfurl a delicate array of 49-foot sails that would spread like blades on a windmill.
The converted intercontinental ballistic missile carrying the craft launched safely at 12:46 p.m. Pacific Daylight Time from the Russian submarine Borisoglebsk. The first part of the launch went according to plan, Planetary Society President Louis D. Friedman said from Moscow, but controllers subsequently observed a great deal of "noise" in the signal during the last part of the launch phase.
Cosmos 1 apparently encountered trouble after its main booster rocket had expended all its fuel. The spacecraft was to have been boosted into its target orbit by a second small rocket, but ground controllers never received data indicating that the second rocket had fired. The situation grew even more grave as ground-based tracking stations detected no evidence that the spacecraft had reached its predicted orbit.
The society describes itself as the largest space advocacy group on Earth, with more than 80,000 members.
Engineers had originally planned to unfold the spacecraft's petal-like sail on Thursday, but it now seemed likely that event would be delayed for several days -- if it could take place at all. If the satellite is, in fact, in a lower orbit, the sail might encounter too much air resistance if it is deployed.
The original plan called for a 30-day stay in space before the satellite was brought back to the ground, but that plan might also be changed.
The long-term goal would be to use a larger sail to propel a craft to other planets in the solar system, using only enough fuel to launch the craft into an initial Earth orbit. Friedman, former Jet Propulsion Lab director Bruce Murray and Sagan began working on such an idea in the 1970s, but Tuesday's launch marked the first realistic test of the concept.
Cosmos Studios in Ithaca, N.Y. -- a science entertainment company founded by Sagan's widow, Ann Druyan -- provided much of the $4-million launch cost.
"Whatever we discover from this mission, if it's not a success, we'll still learn from it," Druyan said. "The way to the stars is hard."
Times staff writer Brad Wible and Associated Press contributed to this report.