Full color reprint of NASA History Office Study of 2007. Illustrated throughout.

Full color publication. NP-2009-066-GSFC. This colorful book provides concise explanations and descriptions-easily read and readily understood-of what is now known of the chain of events and processes that connect the Sun to the Earth, with special emphasis on space weather and sun-climate.

Provides striking full color images from earth-observing environmental satellites in orbit srount the planet. This book shows patterns, shapes, colors, and textures of the land and atmosphere.

With illustrations and photographsp in full color.

A vital, often predominant function in every space mission is that of communications. From the moment of launch, the only connection between spacecraft and earth is the communications system. This system is responsible for sending scientific data back to earth in the specified quality and quantity together with engineering data reporting the condition of the spacecraft. The communications system also provides the capability of tracking the spacecraft and commanding it to take certain actions. Without an effective communications system a successful mission would not be possible. To appreciate the challenge that one faces in designing such systems for planetary exploration, one must consider the enormous distances that are involved. Voyager spacecraft, for example, are now more than one billion miles from earth, tens of thousands of times farther than the most distant communications satellite, and continue to transmit data and respond to commands. The necessity of minimizing spacecraft weight presents a major problem to communications systems designers. The far-reaching implications of spacecraft weight become apparent as the designer considers the problems of providing power supply, antennas, and other necessary devices and supporting elements. Another important challenge is the extreme reliability required of the communications system on the spacecraft. Once the spacecraft is launched, on-board failures can no longer be repaired except by use of redundant systems. System degradation due to aging, imperfect antenna pointing, or imperfect trajectories can be expected; and the designer must know how much degradation to expect from each case and must design the equipment, the operations, and the procedures of data analysis accordingly. The telecommunications engineer works with the most precise and advanced techniques of the engineering world. Since the launch in 1958 of Explorer I, the first free-world satellite, there has been substantial progress in improving communications capability. Even though substantial progress has been made in the last 25 years, space exploration is still in its infancy. There has been no exploration beyond the solar system. There are numerous galaxies and billions of stars to investigate. Bigger and tougher challenges are still ahead; more exciting times are yet to come. These challenges will undoubtedly call for more advanced telecommunications systems to transmit information to and from deep space. Telecommunications technology is still in its infancy. Through the years, a number of telecommunications design techniques, procedures, and analyses contributing to the success of deep space exploration missions have been developed and applied. The purpose of this book is to provide descriptive and analytical information useful for the optimum design, specification, and performance evaluation of deep space telecommunications systems. The book emphasizes system performance information. Long, tedious derivations are not included. The book should serve to acquaint new telecommunications engineers with the techniques available to them and should summarize for the experienced engineers the analyses and information necessary for their work. It also provides a background for understanding the interface between the Deep Space Network and the spacecraft and is intended to facilitate the conceptual designs and analyses for the enhancement of telecommunications performance and assurance of compatibility between spacecraft and ground system capabilities.

Hypersonics is the study of flight at speeds where aerodynamic heating dominates the physics of the problem. Typically this is Mach 5 and higher. Hypersonics is an engineering science with close links to supersonics and engine design. Within this field, many of the most important results have been experimental. The principal facilities have been wind tunnels and related devices, which have produced flows with speeds up to orbital velocity. Why is it important? Hypersonics has had two major applications. The first has been to provide thermal protection during atmospheric entry. Success in this enterprise has supported ballistic-missile nose cones, has returned strategic reconnaissance photos from orbit and astronauts from the Moon, and has even dropped an instrument package into the atmosphere of Jupiter. The last of these approached Jupiter at four times the speed of a lunar mission returning to Earth. Work with re-entry has advanced rapidly because of its obvious importance. The second application has involved high-speed propulsion and has sought to develop the scramjet as an advanced airbreathing ramjet. Scramjets are built to run cool and thereby to achieve near-orbital speeds. They were important during the Strategic Defense Initiative, when a set of these engines was to power the experimental X-30 as a major new launch vehicle. This effort fell short, but the X-43A, carrying a scramjet, has recently flown at Mach 9.65 by using a rocket. Atmospheric entry today is fully mature as an engineering discipline. Still, the Jupiter experience shows that work with its applications continues to reach for new achievements. Studies of scramjets, by contrast, still seek full success, in which such engines can accelerate a vehicle without the use of rockets. Hence, there is much to do in this area as well. For instance, work with computers may soon show just how good scramjets can become.

Human space flight is still in its infancy; spacecraft navigate narrow tracks of carefully computed ascent and entry trajectories with little allowable deviation. Until recently, it remained the province of a few governments. As private industry and more countries join in this great enterprise, we must share findings that may help protect those who venture into space. In the history of NASA, this approach has resulted in many improvements in crew survival. After the Apollo 1 fire, sweeping changes were made to spacecraft design and to the way crew rescue equipment was positioned and available at the launch pad. After the Challenger accident, a jettisonable hatch, personal oxygen systems, parachutes, rafts, and pressure suits were added to ascent and entry operations of the space shuttle. As we move toward a time when human space flight will be commonplace, there is an obligation to make this inherently risky endeavor as safe as feasible. Design features, equipment, training, and procedures all play a role in improving crew safety and survival in contingencies. In aviation, continual improvement in oxygen systems, pressure suits, parachutes, ejection seats, and other equipment and systems has been made. It is a core value in the aviation world to evaluate these systems in every accident and pool the data to understand how design improvements may improve the chances that a crew will survive in a future accident. The Columbia accident was not survivable. After the Columbia Accident Investigation Board (CAIB) investigation regarding the cause of the accident was completed, further consideration produced the question of whether there were lessons to be learned about how to improve crew survival in the future. This investigation was performed with the belief that a comprehensive, respectful investigation could provide knowledge that can protect future crews in the worldwide community of human space flight. Additionally, in the course of the investigation, several areas of research were identified that could improve our understanding of both nominal space flight and future spacecraft accidents. This report is the first comprehensive, publicly available accident investigation report addressing crew survival for a human spacecraft mishap, and it provides key information for future crew survival investigations. The results of this investigation are intended to add meaning to the sacrifice of the crew's lives by making space flight safer for all future generations. Many findings, conclusions, and recommendations have resulted from this investigation that will be valuable both to spacecraft designers and accident investigators. This report provides the reader an expert level of knowledge regarding the sequence of events that contributed to the loss of Columbia's crew on February 1, 2003 and what can be learned to improve the safety of human space flight for all future crews. It is the team's expectation that readers will approach the report with the respect and integrity that the subject and the crew of Columbia deserve.