The great Spanish explorer Alejandro Malaspina's glorious scientific voyage of 1789 to 1794 is celebrated in a small exhibition at the Museum of History and Technology that opened last night.

What? You never heard of Malaspina? Not even with the additional hint that it is he for whom the Malaspina Glacier in southeast Alaska is named?

You've heard of Captain James Cook, the English explorer of that period. Perhaps you've even heard of Jean Francois Galaup de la Perouse, the French explorer of that time. In Malaspina's grant application for the expedition to the Spanish minister of marine, he promises to enter Spain into their "noble rivalry . . . in which navigation, geography and the knowledge of humanity have made very rapid progress"; and, according to the organizers of this exhibit, he succeeded.

But the clue to why he did not become as famous as Cook is on page 41 of the exhibition catalog: "According to evidence presented at the time, Malaspina (aspired to) both political power as chief of state - as well as the personal affections of the queen, Maria Luisa of Parma."

That is, after Malaspina went exploring aboard, he went adverturing at home. And because his adventures were not as successful as his explorations, he was just about expunged from history by the man he wished to replace as chief of state - and lover.

The five-year voyage that Malaspina led to South and North America and parts of anthropological, geographical, zoological and botanical data. What is shown at the Museum of History and Technology is a small part of it, pertaining to the stay in northeastern America and Canada - Indian masks and baskets, drawings of Indians and nature, careful maps.

Cook and La Perouse both died on route, but Malaspina lived to return to Spain a hero. And, like a triumphant astronaut, he began to look as if he had political potential.

He had picked up some liberal ideas on his travels and by associating with the "advanced thinkers of the day," according to Donald Cutter, a Malaspina expert at the University of New Mexico. (The Museum of New Mexico organized this exhibit, which will be here through Feb. 26.)

"He was the hero of the hour and very attractive politically to reformists - imperial reformists, who were interested in a more responsible kingship. He believed in free trade, in the rights of man; he was critical of the colonial system, and was anti-French."

The key to political power then was the queen, Maria Lusia - the tight-lipped lady painted so often by Goya with her weak husband, who looks like a George Washington gone foolish. Manuel Godoy; the queen's lover, was chief of state, and the idea, said Cutter, was "to substitute Malaspina for Godoy, to have him take Godoy's place all round."

Malaspina attempted this by writing letters to the queen. We don't know what was inthem, but Godoy did, because he discovered the letters in the queen's boudoir, and had Malasphina tried for treason.

He was convicted and first imprioned, and then exiled. The multi-volume work he had planned to write on his scientific discoveries was never written, said Cutter, and his name was deleted from accounts of his voyage, while the documents he had gathered were scattered.

"His name hardly ever appears in the published accounts of his work," said Cutter. "It makes it all very sad. Malaspina would have been as famous as Cook - if he hadn't gotten caught."