Air date: 1991-01-08

Runtime: 55 min

NOVA returns to Mount St. Helens a decade after its cataclysmic eruption to learn how nature is recovering from the disaster.

Air date: 1991-04-30

Runtime: 55 min

An experiment that could mean limitless supplies of energy sets the scientific world on its head. NOVA covers the cold fusion controversy.

Air date: 1991-02-05

Runtime: 55 min

NOVA covers the most elaborate expedition ever undertaken in the search for dinosaurs—to China's Gobi desert. Paleontologists brave sandstorms, heat and worse to find their fossils.

Air date: 1991-02-12

Runtime: 55 min

Are dinosaurs still among us? NOVA looks at the contentious question of whether present-day birds are dinosaurs. Over the years, new fossil discoveries keep amending the answer.

Air date: 1991-02-19

Runtime: 55 min

Tyrannosaurus rex, the terrifying kind of the dinos, recently turned up in a nearly complete skeleton in Montana. NOVA follows the dig to extract the bones and looks at the science and lore of dinosaurs in general.

Air date: 1991-02-26

Runtime: 55 min

In the first program of a three-part miniseries on the Soviet space program, NOVA profiles the mysterious genius behind the world's first satellite, the first man to orbit the earth and other early Russian triumphs in space.

Air date: 1991-02-27

Runtime: 55 min

NOVA reveals the details of Moscow's secret plan to reach the moon ahead of the Americans. Was Neil Armstrong's "giant leap for mankind" almost upstaged?

Air date: 1991-02-28

Runtime: 55 min

In an unprecedented insider's look, NOVA covers the training, flight and recovery of a cosmonaut crew that visits the Soviet space station Mir. Unexpected emergencies show that space travel is still far from routine.

Air date: 1991-03-05

Runtime: 55 min

Gregory Peck narrates a scientific voyage around Vancouver Island in search of whales. Humpbacks, Killers, Grays and other whale species make their appearance in spectacular, never-before-seen footage both above and below the waves.

Air date: 1991-03-26

Runtime: 55 min

Will machines be able to beat us at our own game? The computer chess champ matches wits with the human world titleholder.

Air date: 1991-10-01

Runtime: 55 min

NOVA covers the causes and attempted cures of baldness. Some men take pride in their bald heads; others will go to great lengths to cover up. Alan "Douglas Brackman" Rachins of NBC's LA Law hosts.

Air date: 1991-10-09

Runtime: 55 min

In a two-hour special, NOVA follows seven aspiring doctors through four years of medical school. The first examination, the anatomy lab, the first death, the first baby-it's all part of becoming a doctor. Neil Patrick Harris, star of ABC's Doogie Howser, MD hosts. (Follow-up to the program 1521 "Can We Make a Better Doctor?")

Air date: 1991-10-15

Runtime: 55 min

Forty years after they were discovered, the Dead Sea Scrolls have yet to be published in their entirety. NOVA looks at the laborious-some say scandalous-process of compiling and releasing this religious treasure.

Air date: 1991-10-22

Runtime: 55 min

NOVA accompanies Soviet scientists on a deadly mission inside the sarcophagus-the massive structure that entombs the Chernobyl nuclear reactor. Will there be another deadly explosion?

Air date: 1991-11-05

Runtime: 55 min

The tallest mountain in the world? Think again—cartographers had to when satellite date revealed a peak called "K2" might be the real champ. Which is the world's tallest mountain?

Air date: 1991-11-12

Runtime: 55 min

The fastest machines in the sky are going to be slow stuff when the latest speed demons on the drawing board take to the air. NOVA looks at the intoxicating lure to fly even faster.

Air date: 1991-12-03

Runtime: 55 min

NOVA follows the efforts of four participants in a celebrated California study to unblock arteries without using drugs or surgery before their heart disease becomes fatal. A studio segment featuring experts with varying medical views will air as part of the 60-minute program. ABC News Medical Correspondent George Strait moderates.

Air date: 1991-12-10

Runtime: 55 min

This 80-minute NOVA pledge special chronicles the building of the Worldwide Plaza, 47-story office tower in midtown Manhattan, from a hole in the ground to a 770-foot skyscraper.

Air date: 1991-12-17

Runtime: 55 min

The spectacular eclipse of 1991 passed over major observatories on the island of Hawaii. NOVA was there for 6 1/2 minutes of frenetic research that revealed new secrets about our sun.