25 August 2013

Planetary defense: Which strategy will Russia choose?

From: http://rbth.ru/science_and_tech/2013/08/22/planetary_defense_which_strategy_will_russia_choose_29117.html

Planetary defense: Which strategy will Russia choose?

August 22, 2013 Andrei Kislyakov, special to RBTH

Russian researchers have been developing systems to gather data on the most dangerous threats to the Earth — and to destroy them, if need be. Yet a specific strategy for neutralizing space threats has yet to be developed.

The latest news from space is depressing: The threat of space objects hitting the Earth is rising by the year. According to NASA, 16,602 man-made objects were orbiting the Earth as of July 3, 2013.

Only 3,612 of those were active satellites. The rest were space junk of one kind or another. To make matters worse, the Earth has been increasingly under attack by aliens from remote corners of space — asteroids.

“It used to be believed that fragments such as those from the Tunguska meteorite could hit the Earth once in 700–900 years, but now the theory is that such events might occur much more frequently — every 90–100 years,” says Yuri Zaitsev, an academic adviser at the Academy of Engineering Sciences.

More:  Moscow envisions national asteroid-defense system

More asteroids have been discovered over the past decade than in the previous two centuries. “Impacts are all but inevitable — it’s just a matter of time,” the scientist says.

Detect and destroy

According to the general director of the Planetary Defense Center, Anatoly Zaitsev, the “Citadel” International Planetary Defense System — a project presented in March 2013 — should incorporate two or three observer spaceships, reconnaissance satellites to identify asteroid parameters and trajectories, and interceptor satellites capable of destroying an asteroid or changing its trajectory.

The designers estimate it would take around five or six years to create the system, at a cost of around $2 billion.

The leading Russian space corporations have come up with projects of their own. The Energiya Rocket & Space Corporation is prepared to develop a heavy-duty, nuclear-powered carrier to deploy anti-asteroid ammunition in space by 2020 or 2030.

The Lavochkin NPO has developed a sketch of a module designed to land on an asteroid to install a radio transmitter, which would help calculate the space object’s trajectory with more precision.

Initial observations in 2004 indicated a probability thatApophis would strike the Earth in 2029. Additional observations eliminated this possibility. Yet the possibility remained that, during a close encounter with the Earth, Apophis would pass through a gravitational keyhole between 6.5 and 1,970 feet wide, making a future impact inevitable.

Roscosmos head Vladimir Popovkin has stated repeatedly that the choice of defenses should depend on the size, weight, composition and specifications of the dangerous object.

Russian experts tend to believe that nuclear charges should be used to destroy dangerous asteroids and comets. It remains to be seen, however, which space threat neutralization method Russia will eventually chose.

Meanwhile, putting nuclear ammunition in space to counter the asteroid threat might create some international military and political complications. Deputy Prime Minister Dmitry Rogozin stated as much in late February 2013. He believes that certain foreign countries might put nuclear weapons into space for military purposes, in the guise of anti-asteroid weapons.

Reduce the chances of a catastrophe to zero

Physical destruction of asteroids is a matter of the future. Currently, it is most important to gather information on the most dangerous space objects approaching the Earth, such as the asteroid called Apophis.

Although NASA refined its observations in January 2013 and almost excluded the risk of Apophis impacting the Earth during the decades ahead, the risk will not disappear and preparations should start now, the director of the Russian Academy of Sciences’ Space Research Institute, Lev Zelyony, believes.

“I think that the most effective way would be to soft-land a spacecraft on such a threatening object and try to change its trajectory over time, using electric thrusters,” says Zelyony.

Related topic: Space

The technology could be perfected by a joint Russian-American project to capture a small asteroid and tug it closer to the moon’s orbit.

“We are talking about pulling a 50- to 65-foot asteroid into the moon’s orbit using a space tractor, and starting to work with it—perhaps send a manned mission to it, or study it using automatic vehicles,” Vladimir Popovkin said in April. The total project cost could come to $2.65 billion.

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