"The Flight of the Eagle," opening today at the K-B Janus, is a great moviegoing experience--of an exceedingly austere, harrowing kind.

The foreign-language film (with subtitles) reconstructs the events of an expedition into polar regions that would appear to be the Scandinavian equivalent of Robert Scott's ordeal in the Antarctic. Financed in part by King Oscar II and Alfred Nobel, three explorers ascended in a hydrogen balloon, christened Eagle, from Spitzbergen in July of 1897, intending to amaze the world by sailing as far as the North Pole.

The expedition had been postponed a year for want of favorable winds from the south, and the weather began to mock their hopes soon after takeoff, forcing the group to jettison a good deal of expensive ballast to stay aloft and then forcing a landing three days later, with the balloon hopelessly encumbered by ice.

Though splendidly equipped, hardy and resourceful, the men were stranded on arctic ice floes about 200 miles from land and almost 500 miles from their ostensible goal.

Led by a reticent, scholarly mechanical engineer named Salomon August Andre'e, portrayed by Max von Sydow in the film, the lost dutifully performed scientific experiments and kept documentary records of the ordeal as they struggled to survive. This documentation included diaries and photographs, part of the primary source material used by Swedish filmmaker Jan Troell ("The Emigrants" and "The New Land") and his collaborators to re-create the devastating odyssey of the Eagle.

Enlarging with subtly observant, cumulative impact on what would seem to be a scrupulous fidelity to the known facts, Troell is content to present a straightforward chronicle of preparation, adversity, suffering and heroic tenacity that adds up to an overwhelming impression of humanity driven to the limits of physical and psychological endurance.

The filmmaker is no more given to wearing his heart on his sleeve than is the leader of the group, so the emotions well up out of a deliberately restrained, uncoercive style.

In fact, you're not quite certain if Troell's reserve will prevent him from orchestrating the final release of pathos that the story needs to seem emotionally bearable, not to mention powerful.

Troell knows just the right, unwavering camera angle from which to observe an enormously moving, silent duet of reconciliation between von Sydow and the robust, impressive new Norwegian actor Sverre Anker Ousdal, cast as an earthy and profane polar explorer named Kurt Fraenkel, the leader's temperamental opposite and spiritual antagonist. Then there is an image of isolation and loneliness so imposing and definitive that there really is nothing more to be said.

Troell is not inclined to deny or sentimentalize death-defying urges in men. To some extent he even prepped for this achievement with the sequences in "The New Land" depicting the ordeal of a young boy in the wilderness of the American West. The Andre'e party is ready to place survival on the line in pursuit of glory, and in this movie the journey, suicidal or not, finds a beautiful memorial in Troell's reenactment and the touching performances of von Sydow, Ousdal and Go ran Stangertz. THE FLIGHT OF THE EAGLE

Directed by Jan Troell; screenplay by George Oddner, Ian Rakoff, Klaus Rifbjerg and Jan Troell, from the novel by Per Olaf Sundman; edited by Jan Troell; director of photography, Jan Troell; art director, Ulf Axen; music composed by Hans Eric Philip. Produced by the Swedish Film Institute and Jorn Donner. This film runs 141 minutes and is unrated. THE CAST Salomon August Andre'e . . . . Max von Sydow Nils Strindberg . . . . Goran Stangertz Nils Ekholm . . . . Jan-Olof Strandberg Knut Fraenkel . . . . Sverre Anker Ousdal