SPACE

Lighting up Earth

A space mirror has ‘awesome’ implications

PATRICIA CHISHOLM February 8 1993
SPACE

Lighting up Earth

A space mirror has ‘awesome’ implications

PATRICIA CHISHOLM February 8 1993

Lighting up Earth

SPACE

A space mirror has ‘awesome’ implications

PATRICIA CHISHOLM

MALCOLM GRAY

When he is excited, veteran Russian space scientist Vladimir Syromiatnikov, 60, runs his hands through his hair frequently, pushing the grey mass into disorderly spikes. Last week, at the Spaceflight Control Centre in the Moscow suburb of Kaliningrad, Syromiatnikov’s hair stood out in all directions as he spoke of the spectacular space experiment he will help supervise this week. On Feb. 4, Russian aerospace engineers planned to deploy a huge, aluminumcoated plastic disc to deflect sunlight onto the dark side of the earth’s surface. Known as Znamya, or Banner, the socalled space mirror has captured the imagination of space scientists and amateur astronomers around the world. Some of them, describing the Russian experiment as visionary, say that it will have practical applications such as lighting large areas of the earth at night.

Said James Oberg, a space engineer in Houston who is also an expert in Russian aerospace projects: “This is astonishingly fertile technology. The implications are awesome.” But at the same time, some environmental experts have raised concerns about the potential the device may have for damaging animals and plants by disturbing their established light cycles.

Scientists have been discussing the possibility of deploying large, ultra-thin -

structures in space to harness the sun’s energy for decades. Used as mirrors, they could extend twilight, provide light to city-sized polar regions in winter and to remote drilling and mining areas at night, and deliver emergency illumination to search-and-rescue operations. The structures are also critical to the development of still-theoretical solar sailing—using the pressure of sunlight on vast floating sails to power spacecraft. But the ambitious project also faces difficulties. North American scientists warn of delicate technical challenges. The Russian space program also faces serious funding problems. Said Gerald Atkinson, chief scientist in the Space Sciences program at the

Canadian Space Agency in Ottawa: “Projects like the space mirror are partly aimed at promoting international sales of Russian technology and getting funding from other space agencies.” Added Atkinson: “They are trying very hard to keep going under very tough conditions.”

Still, scientists also concede that the Russian

team is made up of veterans who may well succeed in their complex venture. But success will depend on a critical first manoeuvre: deployment of the circular, 66-foot mylar disk. The folded sheet went into orbit aboard the Progress Ml5 robot ship, which docked in October with Mir, Russia’s manned space station. This week, Syromiatnikov’s team expected to separate Progress from Mir, then activate an electrically powered spinning drum to unfold Banner, which has no frame and keeps its shape by revolving. Banner would remain attached to the robot ship for the twoto threeday test.

The satellite’s prescribed orbit is at a rela-

tively low altitude of 250 miles, circling the earth every 90 minutes. Twice in each orbit, it crosses the dividing line between night and day. At those times, Russian technicians have five to seven minutes to fire the rockets on Progress and angle the mirror properly to reflect a circle of sunlight almost four miles in diameter onto darkened areas of the earth’s surface. They anticipate that the reflected light will be about three times brighter than the light from the moon.

If the test goes according to plan, observers who are within the circle of light cast by the reflector will see two bright stars—Progress and the nearby Mir station— and a flash lasting about a second as Banner passes overhead. Those outside the circle will see only what looks like two bright stars. Russian engineers will concentrate on ensuring that Banner is properly aimed when it passes over much of Russia and northern Europe. Although millions of Canadians live in the orbital path and may see both the bright stars and a flash, Russian experts cautioned that the demonstration is highly experimental and the mirror may not be aimed in a way that will make it visible when it is over North America.

But, while the giant mirror offers the tantalizing prospect of extending daylight, some scientists have voiced concerns about disrupting natural light patterns. Said Raymond Cummins, a professor of botany at the University of Toronto: “Extended periods of light could alter the flowering cycles of plants. It could also kill a lot of plants in northern areas if it prevented them from slowing their growth in preparation for winter—the results of that could be scary.”

For now, however, widescale use of mirrors remains only a possibility. Syromiatnikov estimates that a full-scale solar reflector, capable of casting a circle of light in one place for more than a few minutes, would need to be more than 600 feet in diameter and would cost about $12.5 million. Some Western experts estimate that development would, in fact, cost tens of billions of dollars. However, noted John Caldwell, a professor of astronomy at York University and director of the Space Astrophysics Laboratory at the Institute for Space and Terrestrial Science in North York, north of Toronto: “Dreamers don't worry about details like that.” For the visionary Russian scientists, matching their futuristic ideas with cold cash may be their greatest challenge.

PATRICIA CHISHOLM with MALCOLM GRAY in Kaliningrad