Propulsion

Breakthrough Propulsion Physics Project

 

Why Now?

Source: Glenn Research Center
http://www.grc.nasa.gov/WWW/bpp/bpp_WHY.htm

There comes a point when it is time to seek the next revolutions in technology. That point is when the existing methods are reaching the limits of their performance and new possibilities are emerging for alternative methods that might exceed those limits. The limits of ground transportation were surpassed by aircraft. The altitude limits of aircraft were surpassed by rockets. And now, rocket technology is approaching the performance limits of its underlying physical principles. To break through the limitations of rockets, it is necessary to search for alternative propulsion methods with different physical principles. New theories and physical effects have emerged in recent scientific literature that may provide such alternatives. To shape these emerging possibilities to answer the propulsion needs of NASA, the Breakthrough Propulsion Physics Project was established.

Rocket technology is fundamentally limited by its need for propellant. The farther, faster, or more payload carried, the more propellant that is required. This limit cannot be overcome with engineering refinements. This limitation is based on the underlying physical principles of all rocket propulsion - the very physics of its operation. Because a rocket's reaction mass, its propellant, must be carried with the rocket, propellant needs rise exponentially with increases in payload, destinations, or speed. This is true for all forms of rocket technology, from the chemical engines of the Shuttle, through all envisioned nuclear rockets, and even electric ion thrusters. For human journeys into orbit, to the Moon, or to Mars, rocket technology is adequate. For robotic probes to the outer planets of our Solar System, rocket technology is also adequate. However, to dramatically reduce the expense of these journeys or to journey beyond these points in a reasonable time, some new, alternative propulsion physics is required.

Recent advances in science have reawakened consideration that new propulsion mechanisms may lie in wait of discovery. For example, recent experiments and Quantum theory have revealed that space might contain enormous levels of vacuum electromagnetic energy. This has led to questioning if this vacuum energy can be used as an energy source or a propulsive medium for space travel. Next, new theories speculate that gravity and inertia are electromagnetic effects related to this vacuum energy. It is known from observed phenomena and from the established physics of General Relativity that gravity, electromagnetism, and spacetime are inter-related phenomena.

These ideas have led to questioning if gravitational or inertial forces can be created or modified using electromagnetism. Also, theories have emerged about the nature of spacetime that suggest that the light-speed barrier described by Special Relativity might be circumvented by altering spacetime itself. These "wormhole" and "warp drive" theories have reawakened consideration that the light-speed limit of space travel may be circumvented. Today, it is still unknown whether these emerging theories are correct and, even if they are correct, if they will become viable candidates for creating propulsion breakthroughs.

To space technologists such emerging possibilities are of keen interest. The propulsive implications of such emerging science is not a major concern to the general scientific community, however. Instead, much of modern physics is focused on understanding the origins and age of the universe, answering the question of the missing matter of the universe, and probing the physics of black holes and high-energy particle interactions.

In 1990, a team of Lewis Research Center volunteers began an effort to formulate the questions and search for ideas from the scientific literature related to the possibility of creating a "field-drive" propulsion. This informal and unofficial group, called The "Space-Coupling Propulsion and Power Working Group, conducted some experiments and theoretical investigations, and forged collaborations with other scientists and engineers from other NASA centers, other government laboratories, universities, and industry. In particular, this group helped create a growing awareness of the opportunities emerging from science and the need to apply these opportunities to overcome the limitations of rocket technology.

In 1996, following a re-organization of NASA, the Marshall Space Flight Center was tasked to formulate a comprehensive strategy for advancing propulsion technology for the next 25 years. This strategy, called the Advanced Space Transportation Program (ASTP), spans the nearer-term technology improvements for launchers all the way through seeking the breakthroughs that could revolutionize space travel and enable interstellar voyages. To address the most visionary end of this scale, the Marshall Space Flight Center sought out the work of this Lewis Research Center team. Marc G. Millis, the leader of the Lewis team, assembled a group of government, university, and industry researchers to propose the Breakthrough Propulsion Physics Project, as a part of this Advanced Space Transportation Program. In July, 1996, this Breakthrough Propulsion Physics Project was formally established.

The Breakthrough Propulsion Physics Project supports the scientific study of motion through space with the goal of discovering breakthrough means to propel spacecraft farther, faster, and more efficiently. Specifically, this project aims to produce near-term, credible, and measurable progress toward conquering the following 3 breakthrough goals:

(1) MASS: Discover new propulsion methods that eliminate or dramatically reduce the need for propellant. This implies discovering fundamentally new ways to create motion, presumably by interactions between matter, fields, and spacetime, including the possibility of manipulating gravity or inertia.

(2) SPEED: Discover how to attain the ultimate transit speed to dramatically reduce travel times. This implies discovering a means to move a vehicle at or near the actual maximum speed limit for motion through space or by the motion of spacetime itself (if possible, this means circumventing the light-speed limit).

(3) ENERGY: Discover fundamentally new modes of onboard energy generation to power these propulsion devices. This third goal is included since the first two breakthroughs could require breakthroughs in energy generation, and since the physics underlying the propulsion goals is closely linked to energy physics.

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