Space Science on the Ground

The future exploration of space will need more than spacecraft and astronauts. Much research and study can, and must, be done on the ground if we are to go further. Ground-based studies and observations provide the data needed to plan space missions, to support the missions while they are in progress, and to make detailed analy ses of the data that spacecraft gather.

In many cases, ground-based observations are our only source of data about things that spacecraft cannot yet explore: the outermost planets, celestial radio sources, and some aspects of very unusual and distant objects in the universe.

Ground-based astronomy will not die out in the Space Telescope era. There are still many aspects of astronomical research that cannot be accommodated by observatories free of the Earth's atmosphere. Our present radio telescopes are much larger and better equipped for many kinds of observations than anything we can send into space. They not only can listen for the natural and artificial (if any) sources in the radio sky, but they also can transmit radio waves from Earth, to bounce off distant moons, asteroids, and planets, and even the Sun itself. Such measurements can yield hard information on the surface structure and gross physical properties of large asteroids, well before we can hope to explore them with a spacecraft. Optical and infrared telescopes are needed to carry out surveys, to analyze new problems, and to conduct cooperative observations in support of X-ray telescopes and other space instruments.

The collections of extraterrestrial material that we now have - moon rocks, meteorites, and cosmic dust - are still important sources of new data on problems that no spacecraft or telescope currently can properly attack: the physical and chemical nature of asteroids, the early history of planets, the past history of the Sun, and the nature of the solid materials in comets. Even past missions still have much to contribute. The data from our recent Pioneers, Vikings, and Voyagers, which arrived in such floods, are still being studied, sifted, and compared. The continuing analysis of these data is providing further information on the worlds that the missions explored, as well as insight for planning more extensive return visits.

Ground-based scientific studies are the foundation on which all of our explorations of the universe from space have been built. This work is still essential in planning and carrying out future explorations. Just as a spacecraft should not be flown from a poorly constructed and badly maintained launch pad, so our future studies of the universe will necessitate that our ground-based facilities and research capabilities be main tained.