The first "Star Wars" test by men in space ended in failure today when crew members of the space shuttle Discovery found themselves 180 degrees out of position to receive an Air Force laser signal beamed at them from the Hawaiian island of Maui.

It was not clear why Discovery was so far out of position -- backwards -- or why the crew didn't realize it in time to correct it, but flight directors at Houston's Johnson Space Center took the blame for what was easily one of the worst navigating mistakes in more than 20 years of American manned space flight.

An irony of today's incident is that the laser itself worked, shooting its blue-green light from an Air Force installation on the island to the shuttle 230 miles up. So bright did the laser shine in the predawn darkness on Maui that the astronauts were able to see it from space.

Air Force crews on Maui said they hit the shuttle, though the wrong side, and were able to track Discovery by "painting" the DC9-sized spaceliner with a broad light from the laser beam.

Flight directors blamed a "ground-based accounting error" for the snafu. When Discovery's crew ordered its autopilot computer to position the spaceliner for the laser test, the computer placed the shuttle tail forward instead of nose forward.

Flight director Milton Heflin said two major errors were involved. The first, giving the computer a wrong number for the longitude of Maui, was corrected in time. The worse mistake, made too late to correct, was giving the computer the altitude of the spacecraft in feet instead of nautical miles.

The result was that a laser-reflecting mirror positioned in the portside hatch window of Discovery ended up pointing toward space instead of at Earth. Said NASA spokesman John Lawrence: "The error was of such magnitude that it was like looking for the center of the Earth when you wanted to find the surface of the Earth."

Today's failure postponed any test of the laser on Maui with the crew of Discovery until Saturday, when the shuttle will again pass over Hawaii while the islands are in darkness and the spaceliner is in sunlight. This opportunity takes place just before sunrise when the shuttle is passing almost directly overhead.

Though little anguish was demonstrated over the incident by Mission Control Center in Houston and the Discovery crew, their conversations made it clear that they knew they had committed a major gaffe.

"Sorry about that," astronaut James Weatherbee said from Houston once everybody on the ground and in space realized the mistake. "I guess we're going to have to go for the secondary option later on in the flight."

While the brunt of the blame fell on flight directors in Houston, the crew's slow response in realizing the craft was so far out of position was also a factor. The first crew member to pick up the mistake was Commander Daniel C. Brandenstein. It may have been the task of astronauts John M. Fabian and Steven R. Nagel to monitor cockpit instruments indicating their position while Brandenstein and pilot John O. Creighton watched over the spaceliner's cockpit controls.

"Steve and I are taking some amount of static from our commander and pilot," Fabian said sheepishly to Weatherbee about 45 minutes after the incident.

Replied Weatherbee: "I bet you're not getting half the static the flight director's passing out down here."

Two hours after the incident, as the astronauts were getting ready for sleep, the navigating mistake was still on their minds. Crew members were asked how they felt after three days in space. Replied Creighton: "The crew's had a great attitude this whole mission and it's nice to see that the orbiter's got one now." "Attitude" is space talk for position.

Navigating in space around the Earth is not like navigating in the air. An astronaut cannot tell just by looking out the window whether his spaceship is tail first or nose first.

The Earth is often out of view of the forward cockpit windows, where the pilots are, and there is no "up" or "down" in space by which the pilots can orient themselves quickly as the spacecraft speeds along at 17,500 mph.

"You have to look out the window and see the Earth and then look toward north, assuming you know which way north really is," one astronaut explained today. "By the time you've done all this and done it correctly, you've gone a couple of thousand miles through space."

The object of the test was to shoot the laser beam at an eight-inch mirror positioned in the shuttle's hatch window. The aim was to hit the mirror continuously with the beam while tracking the shuttle in space, then receive the beam's reflection off the mirror with a similar device on the ground.

Not everything went wrong on the third day of the seven-day Discovery mission. Early this morning, the crew successfully deployed a third communications satellite, this one for the telephone giant AT&T.

The three-for-three deployments gave the space shuttle 14 successful communications satellite deployments out of 17 tries. None of the three failures was blamed on the shuttle or its astronauts. Onboard engines on two of the failed satellites misfired in space, and an onboard engine on the third satellite never fired.