Space mirrors and solar sailing
Cloudy skies over much of northern Europe in early February partly foiled an attempt by Russian space scientists to light up the night sky with a giant satellite-mounted reflector. The Znamya-2.5 project, which was launched from the Russian Mir space station, involved unfurling a sheet of reflective fabric that was trained toward Earth so that certain cities in northern Russia might receive the sun's rays during hours of darkness.
The experiment was partially successful, according to the Space Regatta Consortium, a group of Russian companies ultimately interested in lighting northern cities with swarms of giant reflectors mounted on satellites. The 82-foot mirror unfurled properly on a second day of experiment and on Feb. 5 a five-km swath of light moved eastward over France, Switzerland, Germany, Poland, and Belarus at a rate of eight kmph. Many people reported seeing a flash of light, but cloud cover prevented a full view.
If this plan proves successful, sailors transiting northern waters could witness a sky cluttered with heavenly bodies. Some people find it difficult enough to identify existing stars and planets for sight reduction. Astronomers are also concerned: light pollution from these giant mirrors would hinder astronomical observation.
The same company is also pursuing a plan to make space vehicles propelled by solar wind, a force strong enough to push spacecraft with large sail area away from Earth's orbit and out into the solar system for extra-planetary visits. Fuel, therefore, would only be required when the craft was launched into space. The proposed launching of a celestial sailing vessel could be within five years, according to the company. Follow the progress of the Russian scientists at src.space.ru.