The new Orient Express will speed from Los Angeles to Peking in as little as two hours. All that's needed to make it happen is a political consensus to support the expenditure of a few billion tax dollars for research.

Dr. George A. Keyworth II, science adviser to the president, and officials from the Defense Department and the Na- tional Aeronautics and Space Administra- tion (NASA) are pushing to build that consensus.

Yesterday they carried their message of technological possibility to a breakfast meeting of the aviation forum, an informal group of members of Congress.

Recent developments in engine technology, light materials and computer controls have created the situation where "we're on the verge of technological revolutions, not evolutions," Keyworth said.

He said research has made it possible to foresee an airplane that "can take off from a standard airport runway, like at Dulles. It can cruise at very high speeds -- in the neighborhood of Mach 10 about 7,410 mph, 10 times the speed of sound or even more -- at altitudes well above 100,000 feet. It can also climb into low Earth orbit."

"That means we're talking about an aircraft that can not only make possible virtually one-hour travel between here and the Far East, but one that can become a relatively inexpensive, flexible means for access to space," said Keyworth.

Passenger fares similar to those on a Boeing 747 today are conceivable, he added.

The effort is known as the Orient Express, named after the famous European passenger train that ran from London to various Mideast destinations. A restored version is now available as an expensive tourist treat.

Keyworth, Dr. James A. Tegnelia, deputy director of the Defense Advanced Research Projects Agency (DARPA), and Dr. Raymond S. Colladay, associate NASA administrator, outlined a three-year, $500 mil- lion research program, starting next January.

If prospects look good after that, they then would want to build an experimental aircraft for $2 billion to $3 billion and have it flying by the early 1990s. Defense would pay 80 percent of the cost, and NASA 20 percent.

Keyworth said that "the president has not yet been briefed" but added that there is "zero doubt in my mind there will no negative votes . . . . " He expressed optimism that there will be "overwhelming public support."

Rep. Bob Carr (D-Mich.) told Keyworth, "Folks just don't like their taxes raised . . . they want the folderol cut out. I've seen optimism turned into anger . . . . " Rep. Dan Glickman (D-Kan.), one of the founders of the aviation forum, said it would be "terrible" if the Gramm-Rudman-Hollings amendment were to eliminate this type of research. "We would leave the field open to Europe and Japan," he said.

The dream of an economically feasible high-speed transport that could cut vast distances to bite-size has long been shared by military planners and commercial airlines.

The fastest growing commercial aviation market is across the Pacific, but flights from the United States to Tokyo and beyond take 13 hours or more.

Of the U.S. manufacturers, McDonnell Douglas Corp. has been most active in research on "hypersonic" aircraft, but all major airframe and engine manufacturers have followed developments closely.

Northwest Airlines, the largest U.S. carrier across the Pacific, had representatives at the meeting and is on record supporting the effort.

United Airlines Chairman Richard J. Ferris told reporters recently, "I hope I will be around the day that Boeing or McDonnell Douglas build a supersonic transport that has the range, the effi- ciency and licks the noise pollution problem."