Earlier this month, the first tourists reached the last earthly frontier of adventure travel: the high, sunlit ice plains of the South Pole. The very first tourist flight to the pole touched down on Jan. 11. The 19 tourists, who were shuttled to the pole in three flights on the 11th and 12th, were greeted cheerfully by the scientists who live under the big aluminum dome of the United States' Amundsen-Scott South Pole Station. But the flight, and the future of similar jaunts, is met with less enthusiasm in Washington, where United States antarctic policy is made.

The flight to the South Pole, conducted by Adventure Network International of Vancouver, in connection with Society Expeditions of Seattle, was without mishap. That's mostly because the operation was meticulously planned, outfitted and backed up; but it may also be because so many people elsewhere were holding their breath, hoping everything would be okay.

Antarctic adventure tourism has a checkered and horror-crossed past, and today, as ships, planes and snowmobiles open this most remote and dangerous continent to more and more casual visitors, antarctic tourism is a source of increasing anxiety to those who run the international scientific programs, including the U.S. National Science Foundation (NSF).

Until the last couple of years, tourism in Antarctica was limited to occasional major private expeditions, a few cruise ships that sailed down from South America each year and one or two annual attempts to do something unusual, such as row across the Drake Passage or walk to the South Pole. That has changed. The National Science Foundation estimates that 7,200 tourists will visit Antarctica this year.

The number is likely to increase. Adventure Network International is planning to continue and increase its flights to the pole, while other organizations step up their overland treks or maritime cruises. Trips by ship to the Antarctic Peninsula, a glorious landscape of fiords, hanging glaciers, penguins, seals, whales and congenial scientific bases, have dramatically increased -- although none of them are cheap. For example:

Lindblad Travel offers three antarctic cruises this year, and Society Expeditions has scheduled nine cruises from December to the end of February; prices run from about $4,000 to $14,000 for 10- to 22-night voyages.

Sobek Expeditions runs two trips of 12 days each from Punta Arenas by plane to King George Island and thence by Chilean freighter around the peninsula area; the price is $3,700 per person.

Mountain Travel of Albany, Calif., has an arrangement to put up to 65 passengers on an Argentine research and supply ship for six separate cruises this year. The minimum price is $2,850 -- probably the lowest price yet offered for a ticket to Antarctica. For an extra couple of grand you can go down on one cruise, spend 15 days at an Argentine base, and go out on the next ship.

Mountain Travel also organizes climbing expeditions to the Vinson Massif, the highest peak in Antarctica, and is the force behind the major ski expedition to the South Pole scheduled to begin in November. This is the most expensive antarctic ticket: The expedition will be made up of 10 adventurers, who will each pay $70,000 -- and get to do camp chores, too.

The onslaught of tourists worries NSF officials for two reasons. First, the sheer volume of visitors has started to get in the way of the scientific research. Sixteen tourist visits were scheduled to the Antarctic Peninsula base, Palmer Station, last year. Although some couldn't get through the ice to the base, enough made it to significantly interrupt the station's schedule. "Sometimes we had to postpone experiments or not start until 11 p.m. and run it all night long," said Robin Ross, a noted antarctic biologist who studies krill at Palmer. "It was hard to keep our science coordinated."

"We like tourists," said Langdon Quetin, Ross' partner. "But you can even get sick on ice cream." This year, for the first time, the NSF has sent an official tourist liaison to Palmer, and has officially limited access to 400 tourists per tour company per season. In a survey of tour companies, the NSF learned that the top four things tourists wanted at Palmer were jacket patches and postal cachets; T-shirts; a look at krill; and to have their photo taken there. Those needs are easy enough to meet without disruption.

"If they had wanted to talk science or to find out what it is like to live there," Ross said wryly, "it would have been more difficult."

The other problem of antarctic tourism is harder to solve: the threat of catastrophe. This is no exaggerated fear; there are still people in the NSF's division of polar programs who helped carry bodies from the wreckage of a New Zealand tourist airliner in 1979. That crash killed 257 people and left a stain on the antarctic travel industry that has been hard to erase.

There have been other incidents. The 1986 triumph of Britons Robert Swan, Roger Mear and Gareth Wood, the first people to walk to the pole since Scott did it and died in 1912, was marred when their support ship was crushed by ice and sank. While they were celebrating at the pole their crew was being rescued by U.S. Coast Guard helicopters. They were flown unceremoniously out of Antarctica by NSF planes. The NSF charged them $30,000.

In December 1985, eight U.S. tourists and two pilots died when their plane hit an island on approach to a Chilean antarctic base. In January 1985, another private British explorer damaged a leg trying to climb a mountain and had to be rescued by combined U.S. and British forces; the rescue required a daring helicopter landing that could easily have led to tragedy itself. Even the U.S. science program has its share of disasters: Last month, a Hercules LC-130 crashed during a salvage operation and two men were killed.

The U.S. program, as policy, turns down all requests for adventure assistance that it gets, and it gets plenty. Some of them are pretty strange. One came from a pilot who wanted to fly an ultralight plane across a continent on which 200-knot winds are not unusual, another from a man who planned to drive his Volkswagen bus to the South Pole.

Playing the ogre to American adventurers is an uncomfortable role for the National Science Foundation. But it is not the National Park Service; its goal is to support scientific research. And, like every nation's operation in the Antarctic, it leaps to the rescue when lives are truly endangered.

But just the thought of being on call as a rescue service angers NSF officials, because each year's schedule is filled to overflowing with scientific work -- such as studying the ozone hole over Antarctica, or learning whether the massive icecap on part of the continent is shifting, which could mean a change in worldwide sea levels. Money is not the only issue; research depends on two things you cannot buy in the Antarctic: good weather and time. Every rescue, like every tour of a scientific base, is accomplished at a cost to science.

Adventurers don't see these costs as unjustifiable, noting that not everyone can be a scientist, and the love of wild places is not restricted to those who can work there. "There has to be a spirit of adventure left in man," said Leo LeBon, president of Mountain Travel.

In this debate, practical questions, such as who will handle search and rescue, become philosophical: People who pursue the human need to struggle with the elements and survive are not being frivolous; what is more important to humankind than the cleaning experience of hardship? Few who work in Antarctica disagree.

But, the NSF says, if rescuers have to show more guts getting you out of a fix than you showed getting into it, where's the glory? Scientists, too, struggle for years to get to Antarctica to do their research; how can you deny one person the adventure of adding to human knowledge in order to help another who goes adventuring for sport? Worse, who pays and in what currency if a Navy helicopter pilot, father of three, dies trying to pluck a rash young climber off a ledge? That hasn't happened in Antarctica yet, but any rescue is haunted by the chance.

Not all nations with stakes in Antarctica are worried about adventure. British ships often assist tourists. Chilean and Argentinean bases support adventurers actively, which brings up another problem: Hosting tourists could be conceived as an act of national sovereignty.

Seven nations claim parts of Antarctica but, by signing the Antarctic Treaty, have agreed with nonclaimant nations, including the United States and the Soviet Union, not to pursue those claims. Since Argentine and Chilean claims overlap, however, those two rival nations have practiced a kind of underground sovereignty, hauling down families to colonize windswept bays and islands, conducting marriages and encouraging the production of babies.

To the dismay of the United States and other nations, Argentine officials have been known to ask for passports at Esperanza Bay, and tourists have willingly complied: Nothing like an Antarctica stamp to impress the customs agent back home. The NSF suggests that Americans keep their passports in their pockets: Each stamp adds a little inky confusion to an international puzzle.

One of the recent additions to this puzzle is a private expedition: the establishment of a year-round base on Ross Island, near McMurdo, by the international environmental organization Greenpeace. Greenpeace seeks to influence world opinion in its drive to have the whole continent declared a world park. If that proposition is to enter into the debate over the continent's future, there must be a place for tourists.

"Antarctic tourism is not controversial," said Adventure Network International's Hugh Culver. "Everyone agrees it's inevitable. What's controversial is how it's done." Culver, proud of his own organization's use of backup aircraft, emergency equipment and care for the niceties of the Antarctic Treaty, said he wouldn't oppose some sort of bonding system to provide for the costs of rescue, nor object to an independent board set up to review adventurers' plans in advance and thus weed out hopelessly dangerous escapades.

The NSF agrees, and has recently sought suggestions on the issue from respected adventurers' groups such as the Explorers Club, the Alpine Club and the Antarctican Society. Guy Guthridge, with the NSF's division of polar programs, suggests that the review of an expedition's iceworthiness might be tied to the bonding process, so no organization could get insurance without approval from the review board.

Such control seems as inevitable as the growth in tourism, but is unlikely to slow it down. Both scientists and adventurers may gain from closer contact; there is no adventure more compelling than research. On this harsh and wonderful continent the gap between scientist and visitor is not vast: Both love a place that is hard on human beings.

One windy September afternoon late in Antarctica's winter, a few Polish and American scientists were standing braced in a Russian-built landing craft in a bay near a Polish base. The Americans were visiting on their way back to South America. But the landing craft had developed engine difficulties; the wind was picking up; swells were rolling the boat and nudging it downwind toward an iceberg that rolled like a livid blue mine in the surf. A leopard seal was patrolling the rough water around the landing craft, as if assessing the taste of the cargo. Suddenly the craft swung around in a trough, sank its flat bow into a wave and brought aboard a load of green water. The salt water was about 29 degrees F. It threw chunks of ice. It cascaded right on top of the Polish base's physician. He vanished briefly, then emerged, his blue jacket soaked, his face and beard running with that bitter water. He grinned hugely.

"Life without adventure," he said, "is not life."

Michael Parfit has spent parts of all four seasons in Antarctica. His book "South Light: A Journey to the Last Continent" was published in hardback by Macmillan in 1986 and was recently issued in paperback by Collier Books.