London, September 11 (ANI): If engineers have their way, Earth's polar regions would soon have watchmen, in the form of 'sailing' spacecrafts poised above the planet, relaying vital data on polar climate change or solar storms.
"Solar sailing" has long been a dream for space engineers, who have envisaged craft exploring the depths of the solar system, propelled only by light.
Such craft could be lighter to launch and would range farther than craft using conventional fuel.
But, according to a report in The Times, scientists are now also exploring more realistic applications that could be deployed in the short term.
Because they will never run out of fuel, solar sailing craft could be used to stay in orbits that would be impossible for conventional satellites.
Once launched into space, solar sailing craft would unfurl giant sails of thin reflective material. Photons - particles of light - hitting the sails would transfer energy to the craft.
Although this force is tiny, in the weightless and airless conditions of space, the craft could build up great speeds.
The constant force provided by solar sails could also be used to hold craft in position indefinitely by effectively expanding the solar system's natural balancing points.
These, known as Lagrange points, exist where the gravitational attractions from two celestial bodies are exactly equal.
According to Colin McInnes, a mechanical engineer at the University of Strathclyde, "Even if you've got quite a small force from your solar sail you can shift the Lagrange point quite substantial distances. Even quite a modest solar sail can have a big effect."
"Because you've got that small continuous force it gives you vantage points for observation that you can't get with conventional spacecraft because you would run out of propellent fairly quickly," he said.
Solar sailing craft would be able to hover above the polar regions, where conventional satellites cannot provide a constant view.
"Given the polar region is of great interest to climate change and environmentally monitoring, having an observation point above the poles is of practical interest," Professor McInnes said.
If positioned near a Lagrange point closer to the Sun, solar sailing craft could also give early warnings of solar storms that threaten to disrupt the Earth's telecommunications, he added. (ANI)