NASA associate administrator Leonard A. Fisk has a message of hope for America's discouraged space scientists. ``The long hiatus in space science ... is drawing to a close,'' he says.
Those scientists haven't launched a planetary mission in 11 years. They have seen their equipment mothballed and plans deferred as NASA's budget tightened and, finally, the Challenger accident grounded them completely.
Now, with the shuttle expected to be back in action soon, the National Aeronautics and Space Administration's top science official says he looks forward to ``what promises to be an exciting year'' in 1989.
Part of the excitement is Voyager 2's visit to Neptune next August and the (expendable) rocket launch of the Cosmic Background Explorer craft to study radiation from the universe's birth.
But it is the scientific shuttle missions that will, if successful, begin to put United States space science truly back in business.
In April, Columbia is to carry up the Magellan Venus satellite to map that planet by radar. In October, Atlantis is to launch the Galileo mission to orbit Jupiter and probe that planet's atmosphere.
Launch of the Hubble Space Telescope, once scheduled for next fall, now is set for no earlier than February 1990, however. And missions to carry an Astro astronomical observatory and to orbit with the European-supplied Spacelab research laboratory in the shuttle bay have also slipped into 1990.
US space scientists generally have mixed feelings about this prospect. They welcome the promised invigoration of their research.
Yet they also feel a sense of d'ej`a vu.
They recall that 1986 was also to be a year of extraordinary excitement. Shuttles were to launch Galileo, the Hubble Space Telescope, and the US/European Ulysses sun-observing mission (now scheduled for launch in October 1990). And Columbia was to have orbited with an astronomical observatory to observe Halley's Comet.
The parallels between the promise of 1986 that turned to frustrating disappointment and the new promise of 1989 remind the scientists that they still are critically dependent on timely operation of the shuttle system.
This is why US space leaders such as Thomas Donahue of the University of Michigan continue to warn that the United States is in danger of losing space science leadership. Scientists spoke out at a two-day symposium at the National Academy of Sciences in July, held to celebrate the 30th anniversary of the academy Space Science Board.
The board itself released a study chaired by Dr. Donahue that emphasized this danger. Restoring US space science vitality will take more than launching long-postponed missions, the board notes. It will take a sustained effort and commitment of resources over the next decade and beyond.
Fisk urges his scientific colleagues to have faith that things will be better this time. Yet he says he understands their wariness. Limited funding has not in itself been a problem.
Fisk explains that there has been plenty of money for NASA's science programs. but NASA wasn't allowed ``to spend it wisely.'' By that he means scientists were forced to use the shuttle even when they had no need for astronauts.
Then, Fisk notes, these scientists watched their project costs balloon as shuttle troubles delayed their missions.
Launch slippage and consequent redesign of the mission raised the cost of the Galileo Jupiter program from $379 million to $843 million, for example.
Everyone involved with US space science now considers shuttle dependency a mistake. NASA is trying to correct this with its ``mixed fleet'' strategy that will provide expendable rocket alternatives. But scientists will still be tied to the shuttle.
Some of the most important projects, such as the Hubble Space Telescope and other astronomical satellites, are designed to be upgraded and repaired by astronauts.
Also, these - and many other missions - will depend on NASA's Tracking and Data Relay Satellite communications network, which must itself be shuttle-launched. Failure of that system could put all such missions out of business.
Then there is the impending space station construction. Space scientists are concerned that the station, like the shuttle, could absorb resources they need. Academy board member James Van Allen of the University of Iowa notes that most US scientists ``do not need the station.'' He says that's why the view of his associates ranges ``from only lukewarm interest to strongly negative,'' when it comes to the space station.
Reflecting this concern, the academy board urges that space science be ``no less central to the space program of the United States than any other [objective].''
The NASA agrees. It also agrees with the academy board that completing projects on schedule is essential. This now has top priority in NASA's strategic science plan.
The academy board is not hostile to the space station. It recognizes that it will be useful for some kinds of science. It especially urges the space agency to push micro-gravity research on new materials, and to study the effects of long-duration space flight on humans.
Also, a European and an American polar orbiting earth observing satellite will accompany the station.
Fisk expects that the space science of the 1990s will bring ``a deeper understanding of our role and our place in the universe.''
He adds that ``the revolution that this understanding will cause in our thinking will rival the one that occurred when Copernicus showed that the Earth was not the center of the universe.''
Fisk has said NASA needs a total budget of $13 billion to $14 billion a year in the 1990s just for near-term plans. If space science receives its traditional 20 percent share, this ``revolution'' may indeed happen. But if that level of support cannot be sustained, or unforeseen shuttle problems again upset NASA's plans, the leadership of the revolution may well pass to Europe, Japan, and the Soviet Union.
Among other things, Europe expects to orbit an infrared observatory in 1993 and the Soviet Union is talking about putting up its own space telescope.