Russia's ambitious plan to light up parts of Europe with a space mirror was put on hold yesterday after a series of faults stopped the 83 ft mirror from opening fully.
Cosmonauts on the Mir space station started the experiment by jettisoning a Progress cargo ship, with the folded mirror attached, just before 10.00 a.m. Irish time.
Just over an hour later, they sent a remote command to unfold the mirror, made of a thin membrane covered by a metal layer.
The segments of a round, silver flower-like structure unfolded only partially, apparently snagging on the cargo ship's antenna.
"It just stopped, that's it," said Mr Gennady Padalka, one of two cosmonauts on Mir, as he looked out the window at the mirror.
Mr Padalka and fellow cosmonaut Mr Sergei Avdeyev then quickly fired the Progress ship's engines by remote control, jarring the mirror, and manipulated the antenna.
The mirror finally unfurled a bit further, but became stuck again, the ITAR-Tass news agency reported, citing Russian Mission Control officials.
The news agency did not say whether the crew would try to revive the experiment.
The mirror was supposed to work like an artificial moon, reflecting sunlight on to several regions in Russia and other former Soviet republics before reaching Germany and the Czech Republic.
If the experiment had gone smoothly, the mirror would have reflected light on a spot about five miles in diameter in a number of agreed-upon places, said Mr Valery Lyndin, a spokesman for the Mission Control.
The experiment has prompted an avalanche of dramatic reports, many of which described the mirror as a "second moon" that would glare from the skies.
But officials connected with the experiment said that was not the case.
"We have been tormented by the media which simply went mad about that, spreading all kind of ridiculous rumours," a spokeswoman, Ms Vera Medvedkova said.
The cosmonauts were supposed to steer the Progress by remote to hold the spot of light steady for about 15 seconds in each area of the experiment.
People in the regions who were looking at the correct sector of the night sky would have seen the mirror as an immobile pinpoint of light, only slightly brighter or larger than an ordinary star, for about 15 seconds.
From space, the crew hoped to see a tiny spot of light on the Earth's surface and wanted to try filming it through Mir's windows.
The mirror's reflected sunlight was supposed to be visible in Bonn and the Czech city of Plzen about 5.45 p.m. Irish time, weather permitting.
Before reaching Bonn and Plzen, the mirror was expected to also illuminate the cities of Aktyubinsk in Kazakhstan and Saratov in Russia, as well as cities in Belarus and Ukraine.
British astronomers gravely concerned over Russian space mirror
British astronomers yesterday expressed "grave concerns" over the glare from the mirror.
The Royal Astronomical Society warned that the technology could threaten scientific studies and interfere with the operation of expensive ground-based observatories.
A statement from the society said: "All such studies will be put at risk and the future development of astronomy could be seriously impeded by the light pollution of the night sky that would inevitably result."
Radar studies of the atmosphere could also be hindered by space mirrors, said the society.