Could Army use high-tech blimp to spy on Americans?

Floating over Maryland's Baltimore suburbs is the newest system launched by the Army to protect the Eastern Seaboard. While officials say the new security system won't be keeping an eye on residents below, many are skeptical, reports CBS News correspondent Chip Reid.

At the U.S. Army's Aberdeen Proving Ground in Maryland, soldiers practiced the complicated choreography of launching an unmanned blimp nearly as long as a football field.

"Every time I see it take off, it literally is like the first time. It's that amazing," Cpt. Matt Villa said.

He said it takes his breath away.

"When it's up in the air, it is literally like a balloon on a string," Villa said.

That string is barely an inch thick and almost 2 miles long. It's made of Kevlar and designed to keep the blimp in place even in hurricane-force winds.

"It could go up to 10,000 feet high," Villa said.

To passing drivers on I-95, about 10 miles away, it looks like a floating white whale and it has thousands of people asking: What in the world is it doing there?

"It's a three-year NORAD exercise that is going to test the integration of this into our missile defense system," Col. Frank Rice said.

If all goes as planned, in about three years, the blimp will approved for permanent duty scanning the sky for incoming cruise missiles. The state-of-the-art radar housed in the bubble underneath the unmanned dirigible has a range of 340 miles -- from Boston to North Carolina.

"We are in the NCR, the National Capital Region, it is our geopolitical center of power in the United States. We have to protect it," Rice said.

He says threats could potentially include missiles launched from a Russian aircraft or submarine, or by terrorists from a highjacked container ship.

Eventually there will be two blimps. He said the one currently undergoing testing will be used to detect cruise missiles in the air while the other would be used to target missile defenses toward any such threat. While he couldn't talk about it in detail, he said the requisite missile defense system is already in place.

Similar blimps have been used on the Mexican border to detect smugglers, and in Afghanistan. But those are equipped with cameras -- and that has some people alarmed.

"People who live in the shadow of this blimp are concerned," Electronic Privacy Information Center associate director Ginger McCall said. She said people have told her they're very unhappy about the blimp floating over their heads.

"It bothers them to look up into the sky and see it looking back at them," McCall said.

Villa said people really needn't worry about the blimp spying on them.

"Like I said, there is no cameras on board and there is nothing that can look at any individual person," Villa said.

McCall wasn't satisfied by that answer, "because I have these documents right here that say that the secondary purpose of this is to surveil and track surface moving targets."

McCall obtained the documents through a lawsuit under the Freedom of Information Act.

"Even without the video surveillance, these blimps are designed to track and surveil surface moving targets, that is people, it's cars, it's individuals going about their daily lives," McCall said.

The Army insists the blimp will never be used to spy on Americans. In a statement, NORAD/NORTHCOM spokesperson Maj. Elizabeth Kreft told CBS News that while the technology for the blimps were "initially developed to provide coverage over a deployed theater," the blimp flying in Aberdeen, which the military refers to as JLENS, is not the same.

"The helium lift technology that takes the radar into the skies is similar, but this sensor suite is completely different," Kreft said in an email. "The JLENS radar and current exercise were designed to look for threats like cruise missiles and it simply cannot see human beings."

However, following revelations about spying by the NSA, some people are nervous about what they believe could one day become the government's eye in the sky.