Arthur C. Clarke, the author and screenplay writer for 2001: A Space Odyssey, put the issue rather starkly some years back when he said: The dinosaurs are not around today because they did not have a space program. He was, of course, referring to the fact that we now know a quite largish meteor crashed into the earth, released poisonous Iridium chemicals into our atmosphere and created a killer cloud above the Earth that blocked out the sun for a prolonged period of time.

This could have been foreseen and averted with a sufficiently advanced space program. But this is only one example of how space programs, such as NASAs Spaceguard program, help protect our fragile planet. Without a space program we would not know about the large ozone hole in our atmosphere, the hazards of solar radiation, the path of killer hurricanes or many other environmental dangers. But this is only a fraction of the ways that space programs are crucial to our future.

We rely on space systems for communicating with many parts of the world, for navigating our airplanes, for coping with weather systems, for charting the path of hurricanes and tidal waves, and for monitoring air and water pollution.

Right now space scientists and engineers are developing new technology to protect us from environmental perils, to alert us to terrorist attacks and to stimulate new industries that actually create new jobs. Cheap energy, essential to sustaining modern life, may very well have to come from space-based energy systems. Every dollar NASA spent on developing the communications satellites industry has put back more than $25 into the economy. It is important for citizens to know that the lack of a space program may truly imperil generations to come. Many people have said the time has come to re-evaluate our space programs, define a new vision and articulate new goals in space. These people are dead right. The time for a major review is indeed now.

It is time for everyone to know and understand the ways that space programs are absolutely critical for solving the largest problems that all people living on our planet now face. NASA Administrator Sean OKeefe and President George W. Bush are welcome to share this list with the American people and members of the U.S. Congress who ask, why do we need a space program?

Prevention of environmental disaster: Remote sensing satellites allow us to monitor the ozone hole, global warming, air, water and ocean pollution, the effect of oil spills on the melting of the ice caps, the loss of rain forests and other environmental threats to human survival. These systems can help us trace our recovery from the worst environmental threats and improve our quality of life.

Creating a global network for modern communications, entertainment and networking: Advanced satellites provide global connectivity by means of the telephone, fax, the Internet, radio and television extend far beyond the reach of fiber optic cables. Eleven thousand television channels are now available via satellite and well over 200 countries and territories are linked via satellite.

Global education and health services: Over 2 billion of the 6 billion people in our world today lack formal educational systems, health care services, potable water or power. The only way to provide global education and health care services in coming decades at reasonable cost and broad coverage is via space-based communication systems. Socrates once said, there is only one good knowledge, and only one evil -- ignorance. In an age of terrorism and great intolerance the need for global education is ever more important.

Cheap and environmentally friendly energy: NASA scientists and engineers already have gone a long way to develop space technology that can provide unlimited low cost energy from space. The operational systems, however, still need to be developed and proven in practice.

Transportation safety: The 6,000 commercial airplanes that are aloft at one time during peak periods in the U.S. depend on satellite navigation for safe operation. New systems can provide better fuel efficiency, earlier warnings of safety hazards and alert of terrorist attack. This is but one of the ways that future space systems can provide greater transportation safety in decades to come.

Emergency warning and recovery systems: The ability to warn populations of pending dangers from hurricanes, monsoons, tidal waves, fires and earthquakes are increasingly dependent on space-based systems. Further rescue operations, from emergency communications to disaster assessment to recovery operations, are dependent on satellite networks as well. Protection of our information networks from cyberterrorists: Many of our current electronic information networks that control transportation systems, energy grids, banking systems and governmental databases are vulnerable. Public Key Infrastructure systems are in need of upgrade. New types of security systems based on GPS location and encryption systems are dependent on space-based systems.

National defense and strategic security: Space has been called the high frontier. National security systems are increasingly based on smart technologies and instruments that operate in outer space. Ever since Operation Desert Storm, military operations are based heavily on space systems and future systems will be even more so.

Protection against catastrophic planetary accidents: It is easy to assume that an erratic meteor or comet will not bring destruction to the Earth because the probabilities are low. The truth is we are bombarded from space daily. The dangers are greatest not from a cataclysmic collision, but from not knowing enough about solar storms, cosmic radiation and the ozone layer. An enhanced Spaceguard Program is actually a prudent course that could save our species in time.

Creation of new jobs and Industries -- a new vision for the 21st century and a mandate to explore truly new frontiers: Most of the economically advanced countries such as Japan, Canada, Australia and Europe, not to mention China, India and Russia, use their space programs to stimulate their economy, expand their educational and health care networks, improve their agriculture, upgrade their information networks, enhance their entertainment networks and create new jobs. In this respect the

U.S. space program now spends precious little of its resources in these areas, but it once did and it could again. These are only some of the ways that space programs could help create a better future for generations yet to come, but it is an impressive list that impacts every American. Space is actually our future. Some would argue that space is the next great step forward for a pioneering nation that sees the need for advancement and discovery. In Nebraska a historical display dedicated to the pioneers that went out West notes that the cowards stayed home but the brave died seeking a better tomorrow. Now is the time to assess our values and our aspirations. It is time to truly ask some key questions:

Why explore space and why send humans into space?

Why does NASA spend the money it does?

Why does NASA use the resources it has the way it does?

What is NASAs role in terms of education, health care, energy and job creation?

Why is there not more international cooperation in space activities?

Should the U.S. government, at all levels, not realize it needs to do a better job telling us why space and space research, exploration and applications are key?

Joseph N. Pelton is director of the Space & Advanced Communications Research Institute at George Washington University and executive director of the Arthur C. Clarke Foundation.