In 1998, the greatest peacetime, worldwide collaboration ever attempted will begin building the largest spacecraft in history. The International Space Station is truly a foothold on the future. This orbiting outpost will provide 21st century Earth with unprecedented research advances.

The Lyndon B. Johnson Space Center in Houston, Texas is NASA's designated Center of Excellence for human operations in space. Human exploration and astro-materials is this center's primary mission in support of the Human Exploration and Development of Space (HEDS) Enterprise. And for good reason. Johnson was established in 1961, first as the Manned Spacecraft Center, and later renamed. Decades of milestone-making work first launched astronauts on quick up and down hops, followed by longer and longer Earth orbiting flights, and outward to land on the moon and return to Earth.

Today, teams of American astronauts wing their way into orbit aboard the Space Shuttle Transportation System. Underway since 1981, Space Shuttle flights have placed hundreds of people into orbit and hauled into space several million tons of cargo. The center has management responsibility for the Space Shuttle program. Johnson's Mission Control Center is where all human space flights are monitored. A new, updated Mission Control Center was completed in 1991, and the new flight control room in the new control center is ready to support International Space Station operations as well as Space Shuttle operations.

Selection and training of astronaut crews is done at the Johnson Space Center. Of paramount interest to NASA is understanding the physiological effects of microgravity. Many changes seen in astronauts are still not completely understood. Among them are leaching of
minerals from bones, reduction in rate of bone formation, atrophy of muscles when not exercised, and motion sickness. All of the effects of microgravity exposure observed in astronauts have so far been reversed after return to gravity conditions here on Earth.

Numbers of Space Shuttle missions have carried specific experiments to better determine physiological changes in astronauts. Johnson is engaged in an intense and sustained effort aimed at understanding the causes underlying these changes and developing ways to prevent them. The increased information about body functions derived from this effort is paving the way for prolonged missions in space, first aboard the International Space Station, then on sojourns back to the moon and onward to Mars.

In preparation of the construction of the International Space Station, Space Shuttle dockings with the Russian Mir space station returned valuable lessons for extended stays on the high frontier.

Since 1995, U.S. astronauts have resided aboard the Mir orbiting complex. At the close of 1997, the U.S. astronaut time aboard Mir totaled twenty-two monthswith eighteen months of continuous occupancy since March 1996. By contrast, it took the U.S. Space Shuttle fleet more than a dozen years and sixty flights to achieve an accumulated year in orbit. Through Shuttle-Mir, NASA has gained valuable experience in rendezvous and docking, spacewalks, and long-duration operation of large-scale systems.

The International Space Station draws upon the resources and the scientific and technological expertise of fifteen cooperating nations, including the United States, Canada, Japan, Russia, and ten member nations of the European Space Agency, and Brazil.

Built in factories worldwide, components for the International Space Station will be lofted into orbit via forty-five launches using three different types of boosters. For five years, an international corps of astronauts will live on and assemble the station in orbit. When completed in 2003, the International Space Station will weigh more than one million pounds. Orbiting at an altitude of 250 statute miles, the huge facility will hold up to seven people when complete.

A science and technology institute in space, an agenda of promising research is to be conducted onboard the International Space Station. Biotechnology, physiology, materials science, combustion science, physics and biology, global environmental observation, and technology developmenthundreds of high-quality science and technology experiments are to be conducted year round.

What are the secrets that gravity masks? As gravity factors are eliminated, what are the results? Aboard the International Space Station, the solidification of metals and alloys, as well as transporting fluids and chemicals in microgravity are to be analyzed. Both scientific and commercial benefit is anticipated from such experimentation. Who can say what new materials, more efficient use of fuel resources, new medicines, advanced computers and lasers, and better communications will prosper by International Space Station research?

Engineers, scientists, and astronauts at Johnson are prepared to begin the nation's quest to master space through the International Space Station. Moreover, the U.S. role in the International Space Station maintains the country's leadership position in human spaceflight and aerospace technology.

Demonstrating its vision of the future, Johnson Space Center is testing recyclable life support systems. Volunteer teams have spent extended periods in a three-story, twenty-foot diameter chamber. These teams are investigating the use of mechanical and chemical means to recycle all air and water, including urine. Some of these physicochemical air and water processors are similar to equipment that will be used onboard the International Space Station. But regenerative life support studies are critical technology for the future of humans in space, because astronauts will not be able to support a trip to Mars or the Moon.

Space engineers at Johnson are also engaged in developing the X-38 prototype space station "lifeboat" or crew return vehicle. To take full advantage of its innovative technology, the X-38 is being designed and tested with an eye toward possible alternative uses as a future international crew transport. Unpiloted X-38 atmospheric test vehicles, built largely at Johnson, are being flight tested in drops from NASA's B-52 aircraft at the Dryden Flight Research Center. An unpiloted space flight test is scheduled for launch aboard a Space Shuttle in 2000. The X-38 is being developed with an unprecedented focus toward efficiency, taking advantage of available equipment and already-developed technology for as much as eighty percent of the spacecraft design.

Johnson Space Center is also the home for research in the fields of life sciences, space systems, robotics, and lunar and planetary geosciences. Indeed, it was a team of Johnson scientists who first found evidence in meteorite ALH84001 that strongly suggests primitive life may have existed on Mars about 3.6 billion years ago. That evidence, while still debated in scientific circles, has fostered considerable research into better understanding the conditions for life, not only on Mars, but on Earth as well.