Space program taking giant, if unsung, leaps

Findings: Though not as dramatic as moon landings, recent explorations have brought us ever closer to understanding the universe.

July 25, 1999|By Julian H. Krolik

THIRTY YEARS AGO this month, a man from Ohio took a walk on the moon. When Neil Armstrong stepped onto the moon, the eyes and ears of the folks back home on Earth followed his every bouncy step and static-laced word. On that night of triumph for imagination, bravery and technological skill, we could thrill to the idea that humankind was beginning a grand new adventure.

By contrast, today's manned spaceflight program seems boringly routine. Few Americans notice the many launches that occur each year. There is the sense that instead of blazing paths through space to new planets, we've become content to have our astronauts simply spin around the block, puttering with experiments as they circle the Earth every 90 minutes. Even the International Space Station is merely a floating bedroom community for Earth, not a vehicle that can carry astronauts to new worlds.

Though it might be a long time before the manned spaceflight program takes a dramatic step comparable to the moon landings (trips to Mars are many years in the future), the American (and world) space program has hardly been dormant since we last sent astronauts to the moon.

It is just that the focus has changed. Precisely because launches have become relatively routine, commercial exploitation of space is a reality. Weather satellites, communications satellites, TV broadcast satellites and global positioning networks have become part of everyday life.

Making launches safer, more predictable -- and thus more boring -- has also enabled us to orbit more complicated scientific spacecraft. What these flying scientific instruments have given us (while perhaps less appreciated than the benefits of having CNN in your hotel room in Timbuktu) is truly spectacular, and gets more exciting by the year.

Before we had access to space, the range of our ground-based telescopes was limited by the blinders imposed on us by the atmosphere. But we've launched dozens of orbiting observatories that map and measure new perspectives of the heavens. We can see a sky that glows in many kinds of light, from infrared to gamma rays.

The Hubble Space Telescope has changed and challenged astronomers' understanding of the universe, giving us clear pictures of galaxies so distant that we are seeing them at a time when the universe was billions of years younger, only one-tenth its present age.

With data such as this, cosmology has been transformed from a patchwork of mythology and guesswork to a genuine experimental science. Once-abstract theories can be tested with observations and measurements, converting shaky estimates into quantitative and credible results. Space-based observations might even permit us to define the course of the universe's expansion from the Big Bang to far into the future.

Other fields of science have been altered by access to space. Geologists now call themselves "planetary scientists" because they are able to see the Earth as only one example of a planet, to be compared with Venus, Mars and the rest of our companions in the solar system.

This expanded view was made possible by the long journeys of unmanned missions to Jupiter, Saturn and beyond. Both Mars and Venus have been mapped in exquisite detail. And the Galileo spacecraft, orbiting Jupiter, has given us spectacular tourist snapshots of such phenomena as the volcanoes on Jupiter's moon Io, as well as discovering oceans of liquid water under the frozen surface of another of Jupiter's moons, Europa.

The kind of truly global view that is possible only from space is also central to understanding problems such as global warming and the infamous "ozone hole." Scientists are even using satellite data to measure the temperature and detect the growth of algae in rivers and lakes, with an eye toward predicting areas susceptible to an outbreak of dysentery.

It is quite possible that when our great-grandchildren study the history of space exploration, they will hear more about how we learned the fate of the universe than what Neil Armstrong said when he took that first small step.

Julian H. Krolik is a physics and astronomy professor at the Johns Hopkins University. Knight Ridder/Tribune News Service distributed this article.

Pub Date: 07/25/99

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