From: Stig Agermose <email@example.com> Date: Wed, 3 Feb 1999 20:40:48 +0100 (MET) Fwd Date: Wed, 03 Feb 1999 20:44:33 -0500 Subject: Russian Space Mirror Experiment Schedule Source: Sky And Telescope http://www.skypub.com/news/special/znamya.html Stig *** Up in the Sky! It's a Bird, It's a Plane, It's Znamya! By J. Kelly Beatty ** Above: When deployed in 1993, Znamya 2's eight reflective panels did not join along their edges as planned. The resulting gaps halved the amount of sunlight reflected onto the darkened Earth below. The object in the center is the Progress-M 15 spacecraft, which carried the experiment into orbit. Courtesy *Energia Ltd. Six years ago Russian space officials conducted an orbital test of a 20-meter-wide (65-ft) reflector called Znamya, the Russian word for banner. The spinning space mirror directed a 4-km-wide (2=BD-mile) spot of reflected sunlight along a swath of Europe that lay in predawn darkness. Although much of the target area was blanketed by clouds, a few observers reported seeing a 1-second-long flash nearly as bright as the full Moon. [Map: Left: Thin yellow lines show the path of Mir over the Earth during the 16-hour test of Znamya 2.5 on February 4th. Heavy yellow lines indicate where the reflector's light beam might be directed during the test. Courtesy of Space Regatta Consortium. (Click on image for larger view).] Buoyed by this success, the Russians will attempt to deploy another giant reflector, dubbed Znamya 2.5, on February 4th. With a diameter of 25 meters, this version incorporates design improvements that should spread the aluminized 5-micron-thick plastic sheet more evenly when it is spun out at 1=BD revolutions per second. Furthermore, Mir cosmonauts Gennady Padalka and Sergei Avdeyev will orient the reflector by remote control, keeping it trained on ground targets for one or two minutes at a time. If all this works as planned, during the 16-hour test several cities in North America and Europe could find themselves briefly bathed in artificial light 5-10 times brighter than the full Moon in the hours after sundown. Observers far outside Znamya 2.5's directed beam will see the spacecraft outshining virtually every star as it coasts across the sky in an orbit 360 km (225 miles) high. Znamya Timetable: 4 February 1999 ( * =3D 5 February) (courtesy Space Regatta Consortium) Moscow time..UT(GMT)..Local time..Event 13:04........10:04................Progress M-40 undocks from Mir 14:34........11:34................Znamya 2.5 reflector deploys 16:12........13:12....18:12.......beam on Karaganda, Kazakhstan 17:45........14:45....17:45.......beam on Saratov, Russia 19:20........16:20....19:20.......beam on Poltava, Ukraine 20:54........17:54....18:54.......beam on Liege, Belgium 20:56........17:56....18:56.......beam on Frankfurt, Germany 2:54*.......23:54....17:54.......beam on Winnipeg, Manitoba 2:56*........23:56....18:56.......beam on Quebec City, Quebec 4:30*........01:30*...18:30.......beam on Calgary, Alberta 4:32*........01:32*...19:32.......beam on Devil's Lake, North Dakota 5:13*........02:13*...............Test ends, reflector is released This cosmic klieg light is the brainchild of the Space Regatta Consortium (SRC), a partnership involving seven Russian aerospace management and engineering organizations. Vladimir Syromyatnikov, SRC's general director, hopes the Znamya test will lead to whole constellations of space mirrors orbiting 1,500 to 4,500 km (1,000 to 3,000 mi) up. With a diameter of 200 meters (650 feet), each satellite could beam down a disk of light as wide as a city and 100 times the Moon's brightness. Syromyatnikov imagines such spacecraft being used to illuminate high-latitude regions of Earth in the hours after sunset or before sunrise, ostensibly to improve the spirits and productivity of those forced to endure long, dark winters. The orbiting beacons might also provide emergency lighting for cities during disasters. Syromyatnikov even envisions using SRC's solar-sail technology to propel interplanetary spacecraft using sunlight alone or to power orbiting observatories. However, the prospect of an armada of giant space mirrors hardly comes as a delight to astronomers. "We're having enough trouble battling light sources on the ground," contends Daniel W. E. Green (Harvard-Smithsonian Center for Astrophysics). "To have to deal with sources from the sky is very disheartening." Some preemptive action has already been taken by radio astronomer Woodruff T. Sullivan (University of Washington). In his role as president of the International Astronomical Union (IAU) commission that deals with light pollution, Sullivan is trying to persuade the United Nations to recognize the night sky as an important part of Earth's environment and to protect it from encroachment by artificial satellites. All this negative reaction is not lost on SRC officials. According to Chris Faranetta, a spokesman for SRC partner Energia Ltd., the consortium has pledged to conduct a full environmental-impact assessment prior to full-scale development. Faranetta also points out that few observatories exist in the far-northern regions that the SRC hopes to illuminate. An open letter to astronomers on SRC's Web site http://src.space.ru offers the hope that these "extremist experiments" will someday provide scientists with "unique tools for real exploration of the farthest corners of the universe." =AE =A9 1999 Sky Publishing Corp. All rights reserved. Please read our *copyright and permissions policy.
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