MOSCOW (AP) _ The crew of the Russian Mir space station will stage what it hopes will be a spectacular experiment Thursday using a huge mirror to reflect a beam of sunlight over Earth.

The Znamya (Banner) experiment envisages unfolding a space mirror made of a membrane covered by a metal layer. In theory, the mirror is to work like the moon, reflecting sunlight onto Europe and North America, Mission Control spokesman Valery Lyndin said Monday.

The mirror, 83 feet in diameter, would serve as a prototype for even larger models that may be used to illuminate sun-starved northern cities. In the more distant future, such devices may act as ``solar sails,'' allowing spaceships to glide through space using solar wind.

If the sky is clear, the space mirror would resemble a shooting star racing quickly across the sky, Lyndin said. Clouds would make it invisible.

Lyndin wouldn't say what exact areas would be illuminated during the experiment. More detailed information will be released on the eve of the experiment, when flight controllers set the precise parameters of Mir's orbit, some 200 miles above the Earth.

The folded membrane is now attached to a cargo ship docked to the station. Mir cosmonauts Gennady Padalka and Sergei Avdeyev will jettison the Progress cargo ship, guide it to some 400 yards away from the station, then send a signal to unfold the mirror.

Once the mirror is fully open, the crew will steer the Progress to hold the spot of light steady and see how the mirror performs. The experiment will last for about four hours and for as many Mir orbits around the Earth.

Eventually, the cargo ship, which is filled with garbage, will be allowed to burn up in the atmosphere as usual.

In 1993, Russia ran a similar experiment but the crew didn't try to maneuver the mirror and it was barely visible only to those who knew its position, Lyndin said.