NO MAJOR POLLUTION FORESEEN FROM SPACECRAFT.

Byline: Jim Skeen Staff Writer

EDWARDS AIR FORCE BASE - Authors of an environmental study prepared to position Edwards Air Force Base for testing future spacecraft found there would be no significant impact to the environment.

Such testing would be equivalent to less than 1 percent of the base's current flight tests, and sonic booms as the craft approached for landing would be much less than those caused by space shuttles, according to the study prepared for the Air Force and the National Aeronautics and Space Administration, which operates the Dryden Flight Research Center at Edwards.

``The selection of Edwards AFB as the preferred landing site for the re-entry corridor is based on extensive capabilities that exist at the site and the fact that flight corridors would most likely be over sparsely populated areas from the West Coast to the inland Edwards AFB landing site,'' the report authors wrote.

The environmental assessment is now out for public comment.

The report notes Edwards' long history with experimental aircraft, ranging back to Chuck Yeager's X-1 flight in the 1940s, the X-15 flights of the 1960s and space shuttle landings since the 1980s.

``Edwards Air Force Base is a cost-effective location for re-entry landings because of the facilities in place, its remote location and previous success in its use for space shuttle and other unmanned vehicle flights and landings,'' the report's authors wrote.

The environmental assessment is not being conducted for any specific aircraft but rather for a ``generic'' one envisioned in the future.

The researchers envisioned a 25,000-pound wingless craft 30 feet long and 15 1/2 feet wide. In comparison, the space shuttles are more than 180 feet long.

The generic vehicle resembles the X-24 ``lifting body'' experimental aircraft tested at NASA Dryden Flight Research Center during the late 1960s and early 1970s.

The report identifies two primary corridors for the approach and landing during testing. The first is a 140-mile-wide western corridor in which the spacecraft would come in over the California coast, between Monterey and Santa Barbara. The spacecraft would cross the coast at an altitude of 108,000 feet.

The second corridor is 240 miles wide as it crosses southwestern Oregon and extends south through California over the Sierra Nevada. The unmanned spacecraft would cross the Oregon coastline at about 160,000 feet above sea level.

A number of other corridors were considered but rejected because they posed a risk of high casualties on the ground in the event of a crash.

The required runway length for the generic craft is between 8,000 and 12,000 feet. Edwards' primary runway is 15,000 feet long and 300 feet wide. No new or specialized equipment would be required to support the unmanned vehicle's approach and landing, the report says.

Approximately 30 minutes before touchdown, the unmanned spacecraft would begin entering the atmosphere at an altitude of about 400,000 feet. At about 45,000 feet and within five nautical miles of Edwards, the spacecraft would begin to maneuver for the final landing approach at the desired altitude and speed.

The final approach and landing would be accomplished through a shuttle-type pattern on either the main runway or on Rogers Dry Lake.

CAPTION(S):

2 maps

Map:

POSSIBLE SPACE PLANE ROUTES

(1) Western Approach

(2) Northwestern Approach

SOURCE: U.S. Air Force/NASA