After the asteroid Orpheus in the
asteroid belt is hit by a
comet, dozens of asteroid fragments are sent on a collision course with Earth, along with a five-mile-wide fragment that will cause an
extinction-level event. While the United States government engages in political maneuvering, the smaller asteroid fragments preceding the main body wreak havoc on the planet, revealing the threat. The United States has a secret
orbiting
nuclear missile platform satellite named
Hercules that was designed by Dr. Paul Bradley. It was intended to defend Earth against a threat like Orpheus, but instead was commandeered by the
U.S. Armed Forces to become an orbiting weapon now aimed at the Soviet Union. After many calculations, it is determined that the fourteen nuclear missiles on board
Hercules are not enough to stop the asteroid. The United States has known that the Soviet Union also has a similar weapons satellite in orbit called
Peter the Great, with its sixteen nuclear warheads pointed at the United States. Needing the additional firepower to stop Orpheus, the President goes on national television and reveals the existence of
Hercules, explaining it was created to meet the threat that Orpheus represents. He also offers the Soviets a chance to save face by announcing that they had the same program and their own satellite weapon. To coordinate the counter-effort between the two countries, Bradley requests a Soviet scientist named Dr. Alexei Dubov. Bradley and Harry Sherwood of
NASA meet at the control center for
Hercules, located beneath
195 Broadway in
Lower Manhattan. Major General Adlon is the commander of the facility. Dubov and his interpreter Tatiana Donskaya arrive, and Bradley gets to work on breaking the ice between them. Since Dubov cannot admit the existence of the Soviet device, he agrees to Bradley's proposal that they work on the "theoretical application" of how a "theoretical" Soviet space platform's weapons would be coordinated with the American platform. Meanwhile, more meteorite fragments strike Earth (one inside
Siberia), and the Soviets finally agree to join in the effort. Both satellites are coordinated and turned toward the incoming large asteroid as smaller fragments continue to strike the planet, causing great damage, including a deadly
avalanche in the
Swiss Alps and a
tsunami that devastates Hong Kong. With hours remaining until Orpheus' impact,
Peter the Greats missiles are launched first as planned because of its relative position to the asteroid, with
Herculess missiles timed to be fired forty minutes later. Immediately prior to
Herculess missiles being launched, a splinter fragment is discovered to be heading toward the command center in New York City. If the center is destroyed,
Hercules will not be able to launch. With seconds to spare,
Hercules receives the signal to fire from the command center and launches its missiles. The splinter impacts the city, destroying the top half of the
World Trade Center twin towers in a direct hit, and creating a large crater in
Central Park. Several workers inside the control center are killed when the facility is partially destroyed by the collapse of the building above, and the survivors are forced to work their way out of the control center by going through the
New York subway system, which becomes a trap due to water from the
East River flooding the tunnels. Meanwhile, the two flights of missiles link up into three successively larger waves. The
Hercules crew reaches a crowded subway station and waits while others try to dig them out. Eventually, the missiles reach the meteoroid. The first wave of missiles strikes the rock, causing a small explosion; the second wave follows with a larger blast, and the third wave creates an enormous explosion. When the dust clears, the asteroid appears obliterated. In New York City, the radios broadcast the good news: Orpheus is no longer a danger to Earth. Just then, the subway station occupants are rescued. Later, at an airport, Dubov, Tatiana, Bradley and others exchange goodbyes before Dubov and Tatiana depart on a plane for the Soviet Union. ==Cast==