‘Star Wars’ Test Blast to Spill Toxic Fuel : High desert: Officials say the ICBM explosion at Edwards Air Force Base will not have a ‘significant impact’ on nearby people or the environment.

The Air Force plans to explode components of an ICBM in a “Star Wars” test at Edwards Air Force Base sometime in the next six weeks, loosing a cloud of toxic rocket fuel in the Mojave Desert. The test should pose no danger to neighbors or the environment, the Air Force said.

Air Force officials announced the test Thursday, saying it would produce a “toxic plume” that they said would remain within the base’s boundaries and cause “no significant impact” to nearby people or the environment.

A spokesman for Edwards, located in the high desert about 90 miles northeast of downtown Los Angeles, said he believed that the two fuel components involved--hydrazine and nitrogen tetroxide--dissipate rapidly after exploding and do not cause widespread contamination.

Dennis Shoffner, a public affairs official at the base, said the test was originally scheduled for Eglin Air Force Base in Florida, but was shifted to Edwards because of Air Force concerns it could harm an endangered species of Florida woodpecker.

The Mojave Desert region where the base is located also is home to a federally protected endangered species, the desert tortoise. But the Air Force said the test “is not expected to have a significant adverse impact” on the tortoises.

The Air Force said it plans to explode missile fuel tanks containing 1,500 pounds of hydrazine and 2,600 pounds of nitrogen tetroxide using a 145-pound charge of C-4 high explosive. About 50% of the nitrogen tetroxide and 20% of the hydrazine will escape the fireball and be dispersed downwind, the Air Force said.

The Air Force said the test, the first of two planned at Edwards, will assess the ability of so-called kinetic energy weapons to destroy enemy nuclear missiles as part of research on the Strategic Defense Initiative, often called “Star Wars.” The test will simulate what would happen to incoming missiles hit by high-speed projectiles.

Shoffner said the first test is scheduled for sometime between now and mid-May, but the exact date depends on the weather. The test must be carried out in winds of no greater than 5 knots--5.75 m.p.h--to ensure that contaminants do not escape the base toward populated areas, the Air Force said.

The nearest communities are Boron and Four Corners, 4 to 5 miles to the northwest of the test site in a remote area about 3 miles inside the northern border of the 300,000-acre base. The environmental clearance document for the test prepared by the Air Force said that they are “outside the toxic corridor” and that “these population centers are not directly in the path of the plume.”

Nitrogen tetroxide is a highly toxic oxidizer that burns rapidly and gives off a potentially deadly cloud of gas. It is used to help power the space shuttles.

Hydrazine is a hazardous but common liquid rocket fuel.

The Air Force for years has trucked shipments of nitrogen tetroxide produced in Mississippi through the far northern portion of Los Angeles County en route to its rocket center at Vandenberg Air Force Base near Lompoc.

The trucking has drawn public protests in the past.

Air Force officials were unavailable late Thursday to explain what happens to unburned rocket fuel dispersed by the explosion. “As I understand it, the materials don’t land on the ground until they’re harmless,” Shoffner said.

Shoffner said the planned test site will be miles upwind from the populated areas of the base, so that its nearly 20,000 daily inhabitants face no danger.