They hover above our heads, out of sight, zooming in and taking pictures.

They aren't interested in the latest celebrity wedding or covert military operation. And the images they take aren't going to make the front page of any magazine or website.

But maybe they should.

That's because the data collected by these powerful satellites have helped save countless lives by allowing meteorologists to warn people about dangerous storms -- sometimes a week before they strike -- with pinpoint accuracy.

Seven days before Superstorm Sandy hit the United States on October 29, computer models based on the data from these satellites predicted the storm would make landfall in New Jersey.

It landed just five miles from where the earliest forecasts said it would.

"It is unprecedented," said Chad Myers, CNN's severe weather expert and meteorologist. "(No) other storm in recent memory has been forecast that good for that long.

"We knew days in advance, much more in advance, 48 hours in advance more than we knew in Katrina (in 2005)."

It could have been a much different story.

A month before the 1,000-mile-wide storm struck the Northeast, at the height of the hurricane season, the geostationary satellite that monitors the Caribbean and Atlantic -- where Sandy gathered strength -- stopped working. While there are dozens of American weather satellites in orbit, these geostationary spacecraft are crucial to predicting dangerous weather patterns.

Luckily, the National Oceanic and Atmospheric Administration, or NOAA, had a backup satellite to scramble into place. Without it, the early warning for Sandy's impending strike on the northeast might not have been as accurate.

That close call has meteorologists worried that, in this era of shrinking budgets, aging satellites might not get the expensive repairs they need to operate, and NOAA might not be able to purchase backup satellites.

Satellites like these are expensive -- $1 billion each -- and they take five years to build and launch.

Compare that to the cost of major storms, like Sandy which is estimated to have inflicted nearly $80 billion in damage in New York and New Jersey alone. Not to mention the cost in human lives.

"If there's a major failure of the satellites, that would be a major disaster and indeed we would be blinded in many respects," explained Kevin Trenberth, who heads climate analysis at the National Center for Atmospheric Research.

"We would not be able to see what's going on in the Earth's system as well as we can now."

Scientists can only wonder how many lives this technology could have saved on September 8, 1900, when a Category 4 hurricane slammed into Galveston, Texas, with no warning, killing at least 8,000 people. It would be another 70 years before satellites were used in weather forecasting.

A major failure of these satellites could pose a serious threat as climatologists and meteorologists warn that storms like Sandy could become more frequent and more powerful in the near future.

Lessons from Katrina

Seven years ago, the only thing protecting the low-lying city of New Orleans from a massive storm surge was an inadequate and outdated system of levees and floodwalls.

After Hurricane Katrina slammed into the U.S. Gulf Coast in 2005 -- killing 1,800 people and inflicting $100 billion in damage -- Congress said never again.

Federal lawmakers spent $14.5 billion, mostly federal funds, to build a fortress around New Orleans.

Today the city is protected by 350 miles of stronger levees and higher flood walls that form a circle around New Orleans to keep any deadly storm surges at bay.

Among its most powerful new weapons: the largest storm-surge barrier in the world.

The massive barrier wall extends nearly 200 feet into the earth, and towers 26 feet above the water. It's reinforced by 350,000 tons of steel -- 50 times the amount in the Eiffel Tower.

The fortress has turned New Orleans into a giant bathtub. To prevent that bathtub from filling up during a major storm, the city built the world's largest water pumping system.

"(One station) can pump about 30,000 cubic feet of water per second, which is just extraordinary," said Garrett Graves, who is overseeing the state's new hurricane protection plan.

At that rate, Graves explained, each of the 77 pumping stations could "fill an Olympic size swimming pool in about 4½ seconds."

It's arguably the best hurricane protection system in the country -- but Malcolm Bowman hopes it won't be for long.

That's because Bowman wants to build a barrier system across the 5-mile-wide opening to New York Harbor that he says could have protected America's most populated city from Sandy's devastating storm surge.

"If barriers and sand dunes had been properly built in the last eight years, none of this would have happened," he said.

Bowman leads the Storm Surge Research Group at Long Island's Stony Brook University. The group promotes a plan to create an elaborate system of barriers and causeways that would virtually flood-proof much of metro New York.

They say their "Outer Harbor Gateway" plan would cost billions of dollars less than the damage that Sandy inflicted upon the state of New York.

Bowman has spent years warning officials of the storm surge risk to New York City.

Less than a month after Katrina, he wrote an op-ed in the New York Times warning that the same thing could happen to New York City -- and outlining his storm barrier system solution to prevent it from happening.

He tried again in 2008 as part of a climate change panel convened by New York City's Mayor Michael Bloomberg.

But no barriers were built.

Today, Bowman is hopeful that New York authorities will green-light his plan. Gov. Andrew Cuomo is awaiting recommendations from a commission that he tasked with finding long-term solutions to protect his state from future weather calamities.

Two commissions on disaster preparedness and response have already offered their recommendations to the governor, who is expected to announce several proposals during his "state of the state" address on Wednesday.

Bowman's idea is not new: Similar barriers already exist in Stamford, Connecticut, and Providence, Rhode Island, and massive barriers are already in operation in the Netherlands and Russia.