Breakthrough Propulsion Physics Program

The Breakthrough Propulsion Physics Activity (BPP) was a analysis activity adjourned by NASA from 1996 through 2002, to abstraction assorted proposals for "revolutionary" methods of aircraft propulsion which would crave breakthroughs in physics afore they could be realized, appropriately the name. During its six years, this affairs was adjourned with a absolute investment of $1.2 million.

Diametrical

The adverse drive was a abstract angle for an "engine" which would actualize a non-conservative gravitational acreage with non-zero curl. It was argued that in such circumstances, the ancillary of the acreage which creates added force on the aircraft will advance the aircraft in the administration of the force.


One abstraction for acumen this abstraction complex academic particles with abrogating mass, originally proposed by Robert Forward and Jamie Woodward. If one were to assemble a block of abrogating mass, and again attach it to a accustomed "positive" mass, the abrogating accumulation would abatement appear the absolute as does any accumulation against any other. On the added hand, the abrogating accumulation would accomplish "negative gravity", and appropriately the absolute accumulation (the spaceship itself generally) would abatement abroad from the abrogating mass. If abiding properly, the ambit amid the two would not change, while they connected to advance forever. It has been argued that adherence issues ability arise.


the abstraction is illustrated according to Millis by :


where :


is the gravitational scalar potential


is Newton's Gravitational Constant


is accustomed mass


is distance

Disjunction

By breach is meant the break of the antecedent of a acreage from amount to which alternation would be with beneath accustomed concrete states. 1 According to a arbitrary of abstract propulsion account on NASA's website

“ This abstraction entertains the achievability that the antecedent of a acreage and that which reacts to a acreage can be separated. By displacing them in space, the agitator is confused to a point area the acreage has a slope, appropriately bearing acknowledgment armament amid the antecedent and the reactant. Although absolute affirmation acerb suggests that the source, reactant, and inertial accumulation backdrop are inseparable, any approaching affirmation to the adverse would accept advocate association to this propulsion application. 2 ”

The abstraction is bidding in algebraic

Pitch and bias

One proposed adjustment of accomplishing a adverse drive, or possibly a breach drive, which was advised in the BPP was alleged the angle drive. This has been declared as involving a academic break acreage which would annihilate the charge for the acreage to be generated on the aircraft itself.

One specific angle for such a angle drive was alleged the bent drive. According to this proposal, if it were accessible to locally adapt the amount of the gravitational connected G in foreground of and abaft the craft, one could actualize a bent drive. While the gravitational connected is a axiological concrete connected in accepted relativity, the Brans-Dicke approach of allure does in a faculty acquiesce for a locally capricious gravitational constant, so the angle of a locally capricious gravitational connected has been actively discussed in boilerplate physicscitation needed. It has been claimedby whom? that one botheration with the abstraction of a bent drive was that it ability actualize a aberancy in the field's acclivity amid central the vehicle.

The bent drive and angle drive is bidding qualitatively in mathematics 4 as :

and

respectively.

where :

is the Gaussian administration over dimensionless

is the consequence of academic angle drive effect

is the consequence of academic bent drive effect

Alcubierre

The Alcubierre drive, aswell alleged the bastardize drive, is a proposal, originally due to the physicist Miguel Alcubierre, which consists of a toy archetypal of a Lorentzian spacetime with backdrop somewhat evocative of the fabulous "warp drive" from the science fiction alternation Star Trek.

Differential sail

The cogwheel captain was addition abstract proposal, which appealed to the zero-point activity field. As the Heisenberg ambiguity assumption implies that there is no such affair as an exact bulk of activity in an exact location, exhaustion fluctuations are accepted to advance to apparent furnishings such as the Casimir effect. The cogwheel captain was a belief that it ability be accessible to abet differences in the burden of exhaustion fluctuations on either ancillary of sail-like anatomy -- with the burden getting somehow bargain on the advanced apparent of the sail, but blame as accustomed on the aft apparent -- and appropriately actuate a car forward.

Legacy

After allotment for analysis ended, the Project's architect and manager, Marc G. Millis, was accurate by NASA to complete the affidavit of results. The acme of that plan is the book, Frontiers of Propulsion Science, which was appear in February 2009, by the American Institute for Aeronautics and Astronautics (AIAA). Chapter 3 (Prerequisites for Space Drive Science) provides refinements and added account of the afterward academic "space drive" propulsion methods: adverse drive, angle drive, bent drive, breach drive, and three variations of cogwheel sails.

After the BPP was canceled in 2002, some above members, including administrator Marc G. Millis, founded the Tau Zero Foundation (named afterwards the atypical of the aforementioned name), an alignment that advocates analysis into interstellar travel. The new alignment is not affiliated with NASA. Millis retired from NASA on February 3, 2010, and continues to accompany agnate analysis via Tau Zero.