The Russians feel depressed. "We have forgotten the old principle of Russian space programmes - to do something first and boast about it only after," said Valery Lyndin of Mission Control in Moscow.
February 4, 1999
ROYAL ASTRONOMICAL SOCIETY
3 February 1999
The President of the Royal Astronomical Society, Professor David Williams of University College, London, wrote on behalf of the RAS to the Director of the Space Regatta Consortium (SRC, the partnership of seven Russian organisations funding the experiment) in September 1998. (At that time the experiment was scheduled for last November.)
The letter points out that astronomers in many countries have developed, at huge financial and intellectual cost, large ground-based observatories at remote dark sites. These observatories make discoveries of immense scientific and cultural importance concerning the origin and development of the universe, and Earth's place within it.
In the opinion of the RAS Council, 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 from the programme proposed by the SRC.
In addition, radar studies of our own atmosphere could be seriously hindered by the presence of many reflectors or large individual reflectors.
The SRC has ambitions to launch whole constellations of space mirrors capable of directing towards the ground a beam of sunlight as wide as a city and a hundred times as bright as the full Moon. Light pollution is already a growing problem, and the RAS's position is that such a major threat to the natural darkness of the night sky is not acceptable.
SKY & TELESCOPE's ELECTRONIC NEWS BULLETIN
Special Edition: February 2, 1999
The Znamya experiment calls for bouncing sunlight off a circular, 25-meter (80-foot) reflector and directing the light toward several cities in Europe and North America after sunset on February 4th. The light beam will be an estimated 5-7 kilometers (3-4 miles) wide. If the experiment succeeds, areas along the ground track could be bathed in light five to 10 times brighter than the full Moon for a few seconds to a few minutes. Cosmonauts Gennady Padalka and Sergei Avdeyev will orient the reflector by remote control, attempting to keep it trained on ground targets for one or two minutes at a time. Observers outside Znamya 2.5's directed beam could see the spacecraft outshining virtually every star as it coasts across the sky in an orbit 360 km (225 miles) high.
Amateur astronomers in the targeted cities or living along the ground track will be well positioned to estimate the brightness of Znamya's reflected beam of sunlight. According to SKY & TELESCOPE magazine, observers near the ground track will see Znamya and Mir appear as a bright, slowly moving "double star." Only if the beam passes directly over your location will Znamya flare to full-Moon brilliance, and then only if the sky is clear. Observers under cloudy skies may see the clouds brighten as if illuminated from within by lightning.
"Most people don't realize you can see orbiting satellites from the ground," says J. Kelly Beatty, SKY & TELESCOPE's senior editor. "Most are quite faint and go unnoticed," he adds, "but this one could get so bright it will be impossible to miss. Those who aren't expecting it may think they've spotted a UFO."
Details about Znamya (Russian for "banner") are reported in SKY & TELESCOPE's February issue and on its Web site (www.skypub.com). This Web site also offers Mir visibility predictions for 100 cities in North America and 100 other cities worldwide.
Here is the February 4th timetable released last weekend by officials of the Space Regatta Consortium (SRC), which is funding the Znamya test. Note that times are approximate and may change a little, depending on Mir's exact orbit at the time of deployment. (* = February 5th)
UT Local time
(GMT) on Feb 4th Event
10:04 Progress M-40 undocks from Mir
11:34 Znamya 2.5 reflector deploys from Progress
13:12 6:12 pm light beam on Karaganda, Kazakhstan
14:45 5:45 pm light beam on Saratov, Russia
16:20 7:20 pm light beam on Poltava, Ukraine
17:54 6:54 pm light beam on Liege, Belgium
17:56 6:56 pm light beam on Frankfurt, Germany
23:54 5:54 pm light beam on Winnipeg, Manitoba
23:56 6:56 pm light beam on Quebec City, Quebec
1:30* 6:30 pm light beam on Calgary, Alberta
1:32* 7:32 pm light beam on Devil's Lake, North Dakota
2:13* Test ends, reflector is released
SRC is a partnership involving seven Russian aerospace management and engineering organizations. They eventually hope to loft whole constellations of space mirrors orbiting 1,500 to 4,500 km (930 to 2,800 miles) high. With a diameter of 200 meters (650 feet), each satellite could beam down a disk of light as wide as a city and up to 100 times the full Moon's brightness. These cosmic klieg lights could be 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. But the prospect of an armada of giant space mirrors has astronomers worried that our view of the starry sky will be spoiled by light pollution from the satellites. "The best way to assess the seriousness of this threat," says SKY & TELESCOPE's Beatty, "is for lots of experienced skygazers both within and outside the ground track to watch for Znamya on Thursday evening and estimate how bright it actually gets." Observing reports may be e-mailed to SKY & TELESCOPE.
On February 4, 1993, SRC conducted an orbital test of a slightly smaller reflector called Znamya 2. The spinning space mirror directed a 4-km-wide (2.5-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.
Additional information is available on SKY & TELESCOPE's Web site.
February 1, 1999
The Znamya-2.5 (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 parts of North America, Europe and Asia.
The mirror, 25 metres 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 driven biy the solar light.
If the sky is clear, the space mirror would resemble a shooting star racing quickly across the sky. In the areas on which the sunlight is reflected, this light could be as bright as the full moon or even brighter.
The folded mylar foil of the mirror is now attached to a Progress cargo ship docked to the station. Mir cosmonauts Gennady Padalka and Sergei Avdeyev will jettison the Progress cargo ship, guide it to some 100 metres 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. A few hours later the cargo ship, which is filled with garbage from Mir, will burn up in the atmosphere.
On February 4, 1993, Russia ran a similar experiment (Znamya-2) but the crew didn't maneuver the mirror. A reflected spot of light of about 5 km in diameter traveled at a speed of 8 km/hour from southern France throgh Switzerland, Germany, Poland and Russia. It was not seen by many people as Western Europe was then covered by heavy clouds.
Astronomers, of course, are strongly opposed against this kind of interference with the night sky. Especially when clusters of space mirrors would be circling the Earth, as proposed by the Russian Space Regatta Consortium. This what dr. David Crawford of the International Dark-Sky Organization (IDA) told ASTRONET:
"Indeed we are are against these things. The night is a right, not just for astronomers, but for all. Anything like this is an obtrusive insult on that right. We need to be able to choose whether we want night light, not have it rain down on us. It also sets a very bad precedence for such things, and even for advertising in space."
Carl Koppeschaar
Back to ASTRONET's home page
Terug naar ASTRONET's home page