Although satellites long ago took over the main job of keeping an electronic eye on Soviet missile and bomber bases, small clusters of U.S. Air Force personnel are still stationed at a 25-year-old radar barricade across the frozen Artic ice-field to warn of a surprise attack.

In some ways, the string of radar stations called the Distant Early Warning, or DEW, line seems like a relic that was overtaken by newer technology but that somebody forgot to shut off.

But U.S. Air Force Col. James Galloway, commanding officer of the 4684th Airbase Support Unit based at this remote airstrip, says the DEW line's mission today is the same as it was 15 years ago and its role is still important.

Galloway's unit -- some 95 enlisted men and women and a dozen officers -- help keep the three DEW line radar sites in Greenland supplied and operating. The sites are part of a string of a dozen or so spread across Alaska. Canada and Greenland facing the polar route over which Soviet missiles and bombers would fly on the shortest line to the U.S. mainland.

Galloway prefers not to see these radars as a "backup" to the satellite early warning systems but rather as a "sister" to them, pumping data back to the Air Force's underground air defense command post in Cheyenne Mountain in Colorado.

In other words, the DEW line network would act to verify, or possibly challenge, data sent back by satellite. Furthermore, he believes, the system has taken on new life because the Soviet Union continues to build new bombers, which might escape other radar detection by flying low once they take off, and also because new low-flying, air-breathing missiles launched by bombers are becoming popular in weapons arsenals.

In the far northern tip of Greenland, the United States also maintains a huge radar station at Thule for signaling warning of a Soviet missile attack. In the 1950s, fighters and antiaircraft missiles also were based there, along with perhaps 5,000 or so U.S. airmen. Today, there are said to be only a few hundred Air Force personnel left at Thule and the fighters and missiles have gone home.

At one time in the early 1960s, there were also more than a thousand men here at an airstrip that resembles a moon base nestled between the walls of an icy fjord. But the U.S. tanker planes designed to refuel big B52 bombers in flight that were here during the last decade are gone too.

Nevertheless, Galloway says morale is high among those who still serve and occasionally dip into the only heated swimming pool in Greenland, on the U.S. base here.

The continued U.S. presence at Thule and here centers on airfields built during World War II when the United States assumed responsibility for protecting Greenland after Denmark was occupied by German forces. In 1951, a defense agreement between the two countries continued the arrangement.

A handful of airmen interviewed generally confirmed that life was okay here despite the remote location. But the Air Force limits tours of duty here to one year and encourages everybody to take two two-week leaves during the year in the United States at four-month intervals.

The Scandinavan Airline System, SAS, which flies in here from Copenhagen, has also been extremely cooperative with the U.S. unit, Galloway says, providing flights to the Danish capital on a standby basis at no charge when seats are available.

A lot of airmen take advantage of that but say they come back broke anyhow because hotel prices are so high in Copenhagen.