On the same day that a meteor exploded over Russia injuring almost a thousand people and an asteroid passed too close to Earth for comfort, the asteroid-mining company Deep Space Industries (DSI) proposes setting up sentry lines in space to track and study rogue asteroids posing a threat to Earth. Using technology originally intended for prospecting for water and minerals on asteroids, the sentry lines of satellites would provide information for deflecting potentially dangerous near-Earth objects.

On Friday, February 15 at 9.26 a.m. local time, a rare instance of a meteor causing injuries and widespread damage occurred in Russia’s Chelyabinsk region. According to reports by Roscosmos and NASA, a meteor about two meters (6.6 ft) in diameter and weighing ten tonnes (11 ton) hit the Earth’s atmosphere traveling at least 33,000 mph (54,000 km/h) and causing a massive sonic boom as it passed over the populated areas.

NASA said at a teleconference that the meteor exploded in a bright flash 12-15 miles (19-24 km) above ground with the force of a 300 kiloton bomb, shattering windows, collapsing the wall of a warehouse at a zinc factory and knocking out mobile phone services.

At least 950 people are known to be injured, and as many as 1,200 reported, with 46 still in hospital, including 13 children who were hit with broken glass as their school’s windows blew in.

This strike happened on the same day as asteroid 2012 DA14 passed the Earth at 1925 GMT at a distance of 17,239 miles (27,743 kim) – the cosmic equivalent of a hair’s breadth.

According to DSI, there are over 10,000 near Earth asteroids big enough to destroy a city and 900 more are discovered every year, yet very little is known about them. DSI’s proposal is to deploy sentry lines of satellites to track and intercept rogue asteroids to determine their threat and how to counter them.

“The hundreds of people injured in northern Russia show it’s time to take action and no longer be passive about these threats,” said Rick Tumlinson, chairman of Deep Space Industries.

The DSI plan is to set up its FireFly satellites to detect and track rogue asteroids. The FireFly was originally designed to target candidate asteroids for mining operations based on value, return times and learn their composition, structure and spin rate. These would be followed by small probes to intercept asteroids and gather close-up data on their structure and composition that would be important in deflecting them.

According to David Gump, CEO of Deep Space Industries, “Placing ten of our small FireFly spacecraft into position to intercept close encounters would take four years and less than US$100 million. This will help the world develop the understanding needed to block later threats.”

These sentries would back up ground-based observations, but would also go a step further. “Observations by space telescopes like the Sentinel planned by the B612 Foundation and the smaller units offered by Planetary Resources should be supported," Tumlinson said. "Astronomical observations are a good first step but at Deep Space we believe we need get up close and personal. Then when these objects are identified, we can launch one or more FireFlies to intercept them, and give us close-up images so that we understand what we are dealing with."

DSI is already developing the FireFly as part of its asteroid mining venture, with prospecting scheduled to begin in 2015. The company believes that the spacecraft could be used for sentry duty without modification. According to a press release, DSI will be working to develop low-cost commercial plans to set up asteroid defenses.

"While our primary mission is the harvesting of asteroid resources, we believe that virtually the same effort and technology can be applied to removing this threat to our precious planet," Tumlinson said.

Sources: Deep Space industries, NASA