"It Gets Better Every Time"

By MICHAEL D. LEMONICK

As the ship roared higher and higher into the cloudless Florida sky, the words of Lisa Malone, the new voice of Launch Control, were cool and precise: "Discovery -- performance nominal." But if Malone, the first woman to deliver the countdown for a space shot, betrayed little emotion, her colleagues at NASA could barely contain their excitement. "It gets better every time," exulted NASA administrator James Fletcher. He had reason to cheer: last week's launch of Discovery, the third shuttle mission since the 1986 Challenger disaster, was another significant milestone in the comeback of the U.S. space program.

The flight's highlight was the deployment of the $100 million Tracking and Data-Relay Satellite, which completes an orbiting communications network that will let the space agency reduce its reliance on an expensive series of ground stations. Much more was riding on Discovery, though, than a single satellite. Without a successful launch, NASA could not hope to stick to its ambitious schedule of seven shuttle flights this year. And those flights are vital to a whole series of important scientific missions, including sending a probe to Jupiter and placing a powerful telescope in orbit. Those launches, plus several other missions that do not depend on the shuttle, could make 1989 the most eventful year in space science since the 1970s.

The next liftoff should come in April, when the shuttle Atlantis is scheduled to send a craft called Magellan on its way to Venus. The space probe will begin orbiting the planet next year, using radar to map its cloud-hidden surface. The best maps now in existence, compiled by Soviet spacecraft, show features as small as a quarter-mile across, but Magellan is expected to do about ten times as well.

In early October a 40-day window will open for the shuttle launch of Galileo, a craft that will head toward the sun, swing around Venus, and then use the earth's gravity to sling itself out to Jupiter. When it arrives in late 1995, Galileo will drop a probe into the seething maelstrom of the giant planet's atmosphere. Then Galileo will rove through the Jovian system to explore its moons.

Come December, NASA plans to use a shuttle to send aloft the Hubble Space Telescope. The so-called ST will fly above the earth's atmosphere, whose turbulence limits the clarity of astronomical photos taken from the planet's surface. The ST's forte will thus be the sharpness of its pictures, which astronomers hope will help answer long-standing questions about the structures of distant galaxies and mysterious pinpoints of light called quasars, and about whether other stars have planets similar to earth.

Even if technical problems ground the shuttle program again, there will still be some big news from space. In July, for example, NASA will use a Delta rocket to launch the Cosmic Background Explorer, a satellite that will study the background microwave radiation that emanates from every part of the cosmos. These microwaves are thought by astrophysicists to be the faint afterglow of the Big Bang explosion, which started the universe, and they pose a riddle. The glow is uniform in all directions to within 1 part in 10,000, implying that the Big Bang was a perfectly uniform explosion. But the modern universe is filled with clusters of matter called galaxies, and there is no clear explanation of how a smooth explosion could produce a lumpy cosmos. COBE's sensitive microwave detectors will try to determine just how perfect the radiation's smoothness really is.

Another burst of information should come in August, when Voyager 2 makes the last swing on its grand tour of the outer planets. Launched in 1977, the probe has already accumulated scientific data and taken spectacular pictures at Jupiter, Saturn and Uranus. Next stop: Neptune. From earth, Neptune appears as a tiny, fuzzy green ball of light, and its major moon, Triton, as an orange dot. Voyager will provide the first closeup view of both. Triton is especially tantalizing, since it is believed to have its own thin atmosphere of methane, and may be partly covered by oceans of liquid nitrogen.

If this year proceeds as planned, NASA intends to keep up the momentum. In 1990 shuttles are scheduled to launch the ROSAT X-ray telescope, the Gamma Ray Observatory and Ulysses, the first probe to study the sun's polar regions. But some experts worry about relying too heavily on the shuttle. "I certainly hope that these missions will go off as planned," says James Van Allen, the University of Iowa physicist who discovered the Van Allen radiation belts that ring the earth. "But the shuttle is not out of the woods yet. After Challenger, NASA should have made a decision to go to expendable rockets for all space science."

The space agency has learned not to raise hopes too high. Galileo, Magellan and the Hubble telescope were scheduled to be launched in 1986, which NASA had confidently proclaimed to be the Year of Space Science. That "year" ended in flames on Jan. 28 with the death of Challenger.

With reporting by Jerry Hannifin/Cape Canaveral