The enlistment of forces and energies known and unknown for advanced propulsion
Posted on Saturday, June 26, 2004 @ 22:33:38 UTC by vlad
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bodebliss writes: This article on the NASA.gov site list topics of interest to all in this field:
Prospects for Breakthrough Propulsion from Physics
(Available as NASA TM-2004-213082)
May-2004
Marc G. Millis
NASA Glenn Research Center, Cleveland Ohio 44145
Abstract
"Space drives," "Warp drives," and "Wormholes:" these concepts may sound like science fiction, but they are being written about in reputable journals. To assess the implications of these emerging prospects for future spaceflight, NASA supported the Breakthrough Propulsion Physics Project from 1996 through 2002. This Project has three grand challenges: (1) Discover propulsion that eliminates the need for propellant; (2) Discover methods to achieve hyper-fast travel; and (3) Discover breakthrough methods to power spacecraft. Because these challenges are presumably far from fruition, and perhaps even impossible, a special emphasis is placed on selecting incremental and affordable research that addresses the critical issues behind these challenges. Of 16 incremental research tasks completed by the Project and from other sponsors, about a third were found not to be viable, a quarter have clear opportunities for sequels, and the rest remain unresolved.
1. Introduction
New theories and phenomena have emerged in recent scientific literature that have reawakened consideration that propulsion breakthroughs may become achievable - the kind of breakthroughs that could make human voyages to other star systems possible. This includes literature about warp drives, wormholes, quantum tunneling, vacuum fluctuation energy, and the coupling of gravity and electromagnetism. This emerging science, combined with the realization that rockets are fundamentally inadequate for interstellar exploration, led NASA to establish the "Breakthrough Propulsion Physics (BPP)" Project in 1996 [1].
This paper summarizes the methods and findings of this Project as well as findings from other parallel efforts. The methods are described to reflect the special management challenges and corresponding mitigation strategies for dealing with such visionary topics in a constructive manner. Projections of future research are also offered.
2. Methods
As the name implies, the BPP Project is specifically looking for propulsion breakthroughs from physics. It is not looking for further technological refinements of existing methods. Such refinements are explored in other NASA projects. Instead, this Project looks beyond the known methods, searching for further advances from emerging science from which genuinely new technology can develop - technology to surpass the limits of existing methods.
2.1. Technical Challenges
The first step toward solving a problem is to define the problem. The following three Grand Challenges represent the critical discoveries needed to revolutionize spaceflight and enable interstellar missions:
Challenge 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 interacting with the properties of space, or possibly by manipulating gravitational or inertial forces.
Challenge 2 - SPEED: Discover how to dramatically reduce transit times. This implies discovering a means to move a vehicle near the light-speed limit through space, or by manipulating spacetime to circumvent the light-speed limit.
Challenge 3 - ENERGY: Discover fundamentally new modes of onboard energy production to power these propulsion devices. This third goal is included since the first two breakthroughs might require breakthroughs in energy generation, and since the physics underlying the propulsion goals is closely linked to energy physics.
2.2. Special Challenges and Mitigations
The combination of high-payoff prospects plus the speculative nature of the edge of knowledge evokes special management challenges. To produce credible progress under these conditions, the BPP Project employs the following operating strategies:
Reliability: Success is defined as acquiring reliable knowledge, rather than as achieving a breakthrough. This emphasis steers publications toward credible progress and away from sensationalistic claims.
Immediacy: Research is focused on the immediate unknowns, make-or-break issues, or curious effects.
Iterated: Overall progress is achieved by repeating a cycle of short-term, incremental tasks.
Diversified: Multiple, divergent research topics are explored simultaneously.
Measured: Progress is tracked using a combination of the scientific method and the applicability of the research to the Project's goals.
Impartial: Reviewers judge credibility and relevance, but are not asked to predict the feasibility of research approaches.
Empirical: Preference is given to experiments and empirical observations over purely analytical studies.
Published: Results are published, regardless of outcome. Null results are also valuable progress.
Given the kind of fundamental investigations sought by this Project, it is difficult to reliably determine technical feasibility during a proposal review. Such an assessment would constitute a full research task itself. Typically, when confronted with the kind of unfamiliar ideas related to this endeavor, many reviewers will reflexively assume that the new idea will not work. To prevent premature dismissal, proposal reviewers are asked to judge if the work is leading to a result that other researchers will consider as a reliable conclusion on which to base future investigations. This includes seeking tasks that can demonstrate that certain research approaches are not feasible. This posture of judging credibility, rather than pre-judging correctness, is one of the ways that the BPP Project is open to visionary concepts while still sustaining credibility.
3. Findings
In addition to the 8 tasks supported through the BPP Project, at least 8 additional tasks were supported by others, and several related research efforts continue. Of the 16 specific tasks reported and summarized here, 6 were found not to be viable, 6 remain unresolved or have debatable findings, and 4 have clear opportunities for sequels.
It should be stressed, however, that even interim positive results do not imply that a breakthrough is inevitable. Often the opportunity for sequels is more a reflection of the embryonic state of the research. Reciprocally, a dead-end conclusion on a given task does not imply that the broader related topics are equally defunct. Both the null and positive results should only be interpreted within the context of the immediate research task, and not generalized beyond. This is consistent with the operating strategy to focus on the immediate stage of the research, and the strategy to put a higher priority on the reliability of the information rather than on producing broad-sweeping claims.
It should also be stressed that these task summaries do not reflect a comprehensive list of research options. It is expected that new concepts will continue to emerge in such an embryonic field.
3.1. BPP Sponsored Research
The NASA BPP Project sponsored 5 tasks through competitive selection, 2 in-house tasks, and 1 minor grant. From this work, 13 peer-reviewed journal articles resulted [1-13]. Summaries of each of the 8 tasks are offered below.
3.1.1. Define Space Drive Strategy. "Space drive" is a general term to encompass the ambition of the first BPP Challenge: propulsion without propellant. To identify the unresolved issues and research paths toward creating a space drive, this in-house task conceived and assessed 7 hypothetical space drives. The two largest issues facing this ambition are to first find a way for a vehicle to induce external, net forces on itself, and secondly, to satisfy conservation of momentum in the process. Several avenues for research remain, including: (1) investigate space from the perspective of new sources of reaction mass, (2) revisit Mach's Principle to consider coupling to surrounding mass via inertial frames, and (3) investigate the coupling between gravity, inertia, and controllable electromagnetic phenomena [2]. These are very broad and open areas where a variety of research sequels could emerge.
3.1.2. Test Schlicher Thruster. In-house experiments were performed to test claims that a specially terminated coax, as reported by Rex Schlicher [14], could create more thrust than attributable to photon radiation pressure. Tests observed no such thrust [15].
3.1.3. Assess Deep Dirac Energy. Theories based on the work of Dirac assert that additional energy levels and energy transitions might be possible in atomic structures [16]. A theoretical assessment, supported via a grant to Robert Deck (Univ. Toledo, Grant NAG 3-2421), found that several of the predicted energy transitions are not possible. Other unexplored possibilities remain. This topic is not fully resolved. Findings have been submitted for journal publication.
3.1.4. Cavendish Test of Superconductor Claims. As a lower-cost alternative to a full replication of the Podkletnov "gravity shielding" claim [17], Cavendish balance experiments were performed using superconducting materials and radio frequency (RF) radiation according to related theories. It was found that the RF radiation coupled too strongly to supporting instrumentation and prevented any discernable results [18]. No sequels to this approach are expected.
Other groups sponsored full replications of the Podkletnov configuration, and their findings are presented in section 3.2.3.
3.1.5. Test Woodward Transient Inertia. Experiments and theories published by James Woodward claim that transient changes to inertia can be induced by electromagnetic means [19, 20], and a patent exists on how this can be used for propulsion [21]. Independent verification experiments, using techniques less prone to spurious effects, were sponsored. Unfortunately, when subsequent publications by Woodward indicated that the effect was much smaller than originally reported [22], the independent test program had to be changed. The revised experiments were unable to resolve any discernable effect with the available resources [23]. Woodward continues with experiments and publications [24], and has begun addressing the theoretical issues identified during this independent assessment. This transient inertia approach is considered unresolved.
3.1.6. Test EM Torsion Theory. Theories using a torsion analogy to the coupling between electro-magnetism and spacetime [25] indicate the possibility of asymmetric interactions that might be of use, at least in principle, for propulsion [26]. Experiments were sponsored to test a related prediction of the theory, but the results were null. Further analysis indicates that the experiments missed a critical characteristic to correctly resolve the issue [27]. This approach is considered unresolved.
and much, much more.
I know you guy relish this stuff like I do. Enjoy!
Bode Bliss
Note: Also see the earlier article: "Commentary on Millis's 2004 NASA BPP Report"
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