I n July of 1803, just before Lewis and Clark began their historic expedition, a Boston newspaper derided the value of the lands newly acquired in the Louisiana Purchase as, “a great waste, a wilderness unpeopled with any beings except wolves.” The article gave voice to those who opposed both the purchase of those lands and their exploration as an expensive adventure at a time of national need. Today, as we anticipate the next great age of space exploration, we may wish to remember a central lesson of Lewis and Clark’s “Corps of Discovery” — one confirmed and reconfirmed throughout history. The lesson is that exploration does not slow a nation’s progress, but accelerates it.

Our first age of space exploration conferred benefits on America that defy calculation: a ccurate weather forecasting; precision global navigation; improved communications; a greatly enhanced understanding of our planet and our universe; an engineering and aerospace work force that helped place us at the world’s technological forefront. And let’s not forget the imaging satellite. The forewarning it affords has made our nation safer, and its ability to verify treaty compliance has helped control the proliferation of dangerous weapons and associated technologies. These benefits were largely unforeseen when U.S. Presidents Dwight D. Eisenhower and John F. Kennedy chose to explore space a half century ago.

Around the world governments have worked hard to add their names to the growing roster of space faring countries. One new addition, China, has even added human spaceflight to its ambitious program of robotic exploration. Indeed, that balance between human and robotic exploration is one measure of a serious exploratory vision. China and other nations recognize their deepening dependence on space and are determined to participate in the explorations soon to come. U.S. President George W. Bush has stated that the next age of discovery will be a journey, not a race. Yet even journeys need leaders and it is critical to our nation and the world that the United States assumes that role.

The commercial sector will bring innovation and agility to the effort, but the government’s role cannot be substituted. “Basic research is what I’m doing when I don’t know what I’m doing,” said the father of the Apollo program, Wernher von Braun. Like basic research, exploration has no pre-determined result in mind. Jonas Salk discovered the polio vaccine while conducting basic research at a public university. Corporations, by contrast, are beholden to their stockholders and can rarely initiate an investment without a planned return. The reach of space exploration must exceed the commercial sector’s grasp, and only NASA can lead the way.

Adventure was the Corps of Discovery’s companion, not its objective. President Thomas Jefferson required that the tasks of Lewis and Clark include scientific research, analysis of trade and economic potential, and the discovery of land and water routes for commerce and immigration. Theirs was an age of discovery and they knew that, though exploration makes no promises, it usually returns results. In 1803 no one foresaw the astonishing productivity of western farmlands or the economic boon of plentiful oil. No one imagined the great cities, industries and universities those lands would spawn. No one anticipated the grandeur of Yellowstone or the national parks system that was born there. President Jefferson simply understood that the nation’s destiny lay west, and to abstain from its exploration would be to deny his countrymen their future.

We face too many challenges to remain withdrawn from the exploration of space. The quest is inevitable. The vision is in place. Skeptics will warn of waste and wolves, but the challenges and opportunities of our times demand that we lead the journey toward unknowable benefits and new progress.

Ron Sugar, PhD, is c hairman, chief executive officer and president of Northrop Grumman Corp. , and a member of the National Academy of Engineering with more than 35 years experience in design and management oversight of NASA and military space programs.