Earth Observing Satellites

Earth-observing satellites are robot spacecraft that use remote sensing technology to routinely collect a wide variety of data across the electromagnetic spectrum. These data support national defense, scientific research, environmental monitoring, meteorology, and commercial activities. Aerospace engineers custom-design each Earth-observing satellite (or family of such spacecraft) to serve the needs of a particular user. For example, Earth-orbiting military satellites apply remote sensing...

Rocketry In The Age Of Science And Reason

During the sixteenth and seventeenth centuries, Europe experienced profound changes in intellectual thought that ushered in the early modern age. The changes, loosely called the scientific revolution, laid the foundation for understanding the workings of the universe that ultimately led to space flight. Nicolaus Copernicus began a revolution in astronomy with the publication in 1543 of On the Revolutions of Celestial Spheres. The book suggested a heliocentric model of the universe with Earth,...

Space Transportation System STS Space Shuttle

The official name for NASA's space shuttle program is the U.S. Space Transportation System (STS). The space shuttle is a mostly reusable, delta-winged aerospace vehicle that launches into space like a rocket, but then returns to Earth by gliding through the atmosphere and landing on a runway like an airplane. The space shuttle is the world's first and only operational reusable aerospace vehicle. As the name aerospace implies, this vehicle operates in Earth's atmosphere and in outer space. The...

Space Technology and the Creation of a Transparent Battle Space

Space technology has greatly influenced the nature and conduct of modern warfare and is now an inseparable part of national defense. Space systems are the primary source of warning of an impending attack and can fully characterize that attack. Highly capable reconnaissance satellites monitor arms-control agreements and continually provide data that help intelligence analysts assess the world situation and avoid military or political surprises. Collectively, these capabilities represent...

Prehistory To Medieval Europe

The story of space technology is interwoven with the history of astronomy and humankind's interest in flight and space travel. Most ancient societies developed myths and stories of human flight, even spaceflight, and were curious about the lights in the night sky. The Babylonians, Mayas, Chinese, and Egyptians all studied the sky and the motions of the planets. Nevertheless, it was the Greeks who had the largest impact on early astronomy, developing models and theories that shaped the...

Liquid Propellant Rockets

The other major type of chemical rocket is one that uses liquid propel-lants. Compared to the solid-propellant rocket, the liquid-propellant rocket is a very complex device. Liquid-propellant rockets have three principal components in their propulsion system propellant tanks, the rocket engine's combustion chamber and nozzle assembly, and turbopumps (see Figure 4.6). The propellant tanks are the load-bearing structures that contain the liquid propellants. There are separate tanks for the fuel...

National Reconnaissance Office

The National Reconnaissance Office (NRO), an agency of the Department of Defense, is responsible for U.S. spaceborne reconnaissance. The technology and expertise the NRO developed made a significant contribution to the early U.S. space program. In the 1950s, rapid Soviet nuclear weapons developments along with that nation's long-range bomber and missile-delivery systems created the possibility of a devastating surprise attack a nuclear Pearl Harbor. To monitor Soviet activity, the United States...

Newtons First Law of Motion

Newton's first law of motion is just a statement of easily observable physical fact. It states that if a body in motion is not acted upon by an external force, its momentum remains constant linear momentum (p) mass (m) X velocity (v), or p mv. But to really know what this implies, you must understand the scientific meaning of the terms rest, motion, and external unbalanced force. Think of rest and motion as the opposite of each other. Rest is the state of an object when it is not changing...

Johannes Kepler 15711630

German astronomer and mathematician Johannes Kepler discovered three major laws of planetary motion that now bear his name. Kepler's laws are used extensively in the age of space to describe the motion of natural and artificial satellites as well as that of unpowered spacecraft in orbit around planets. Kepler was born on December 27, 1571, in Weil der Stadt in the duchy of W rttemberg (in present-day Germany). His father was a mercenary soldier who abandoned the family, and his mother was once...

Reusable Launch Vehicle RLV

The reusable launch vehicle (RLV), currently only in the conceptual state, is an aerospace vehicle that includes functional designs and fully reusable components to provide low-cost access to space. The RLV employs twenty-first-century space technology and innovative payload- and vehicle- processing techniques to achieve airline-type operations in delivering pay-loads into low Earth orbit (LEO). Aerospace experts believe that they can construct an operational RLV, but recognize that complete...

Rocket Fundamentals

A rocket is a completely self-contained projectile, pyrotechnic device, or flying vehicle propelled by a reaction engine. In its simplest form, it is just a chamber enclosing a gas under pressure. A small opening at one end of the chamber, called a nozzle, allows this pressurized gas to escape. As the gas rushes out through the nozzle, it produces a reaction thrust that propels the rocket in the opposite direction. An inflated balloon can help us understand this concept. Within its elastic...

Propulsive Upper Stages

Quite often, getting a payload into low Earth orbit (LEO) is only part of the overall propulsion effort. Some payloads need an upper-stage vehi cle, a rocket that boosts them to a higher-altitude operational orbit or onto an interplanetary Earth-escape trajectory. Aerospace engineers use an upper-stage vehicle to accomplish this task. This special vehicle rides into LEO attached to the payload. Once deployed from the launch vehicle, the upper-stage rocket engine then fires to send the payload...

Chronology of Space Technology and Exploration

This chronology presents some of the key events, scientific concepts, and political developments that led to and then formed the age of space. Several of the entries correspond to events now obscured in antiquity, while others are associated with the emergence of modern science during the late Renaissance period in Western Europe. More recent entries highlight how stories of spaceflight in the science-fiction literature of the nineteenth century stimulated technical visionaries at the dawn of...

Hazards of Human Spaceflight

Another critical issue centers around this probing question Why send people on high-risk missions when machines can do the job, often at a far lower cost This debate extends across the entire spectrum of space missions from planetary exploration to in-orbit assembly, construction, and repair. It is a very difficult question to ignore and an even more difficult question to respond to. On one side are technical experts who strongly advocate the exploration and use of space, but want to minimize...

Wireless Switchboards In The

Early in the twentieth century, physicists and communications engineers recognized that radio waves, like other electromagnetic waves, propagate along the line of sight that is, they travel in a straight line and cannot of themselves bend around the curvature of Earth. Consequently, a radio or television receiver cannot obtain broadcasts from a transmitter that lies beyond the horizon. The higher the transmitting antenna, the farther the line of sight available for direct-wave, wireless...

Space Technology and the Information Revolution in National Security

Reconnaissance satellites, surveillance satellites, and other information-related Earth-orbiting military spacecraft changed the nature of military operations and national security planning forever. Space-based information collection produced enormous impacts on peacekeeping and war fighting and immediately became an integral part of projecting national power and protecting national assets. For simplicity, reconnaissance systems use their sensors to search for specific types of denied...