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The first-ever Interstellar Session at the UK Space Conference took place on the 4th April 2009. Up to 50 interested people watched the presentations, which covered a wide range of topics as different as unconventional methods to generate interest and public support, quasi near-term opportunities like a mission to Sun's gravitational focus, the prospects of fusion-driven spaceships and some touching the very foundations of physics like relativity, inertia, Casimir energy and wormholes - all in relation with interstellar travel. Special thanks go to Kelvin Long for the organization of this pioneering event!
The website of the session is here:
Presentations
Claudio Maccone:  Realistic Targets for Early Interstellar Missions
Abstract: The nearest
stellar system, the Alpha Centauri three stars system, is located about
4.40 light-years away. This amounts to 278,261 AU. But at only 550 AU,
or, more generally, at only about 1,000 AU, the focus of the
gravitational lens of the Sun is found, that is then 278 times closer
than our nearest interstellar target. In other words, assuming equal
engineering problems, the trip to the Sun focus takes 278 times less
than the trip to the nearest stellar target. This makes the Sun focus a
reasonable target for our probes to reach within this century. It also
plainly appears that, before we send a probe towards anyone of the
nearest stellar systems, we’ll need a detailed radio map of that
stellar system. In other words, we need a huge radio magnification of
all objects located in that neighborhood, and nothing is better than
the huge magnification provided by the gravitational lens of the Sun.
Thus, sending a preliminary probe to 1,000 AU in the direction opposite
to the target stellar system clearly must be done before any
interstellar flight to that stellar system is even designed, not to say
attempted. In this paper a status review is presented about the “FOCAL”
probe to 550 or 1000 AU. The relevant scientific, propulsion and
telecommunication issues are briefly summarized and updated.
Tibor Pacher:
Unconventional Thinking in Interstellar Spaceflight Research: Practical Approaches
Abstract: Interstellar
space flight and closely related topics likes a possible encounter with
extraterrestrial life are on the edge of interdisciplinary research. By
their very nature these topics require unconventional thinking. I
discuss two practical approaches which are expected to generate new
ideas for practical interstellar flight, involve the public and are
purposely not restricted to academics: a) make a provocative but
accountable prediction (an example for this is the Interstellar Bet,
see www.longbets.org/395) b) call for Crazy Ideas and publish them in a
controlled way on the web (see the Crazy Ideas section at
www.peregrinus-interstellar.net ). Special attention is paid to the
following aspects: a) how to meet the often sceptical attitude of the
scientific community to out-of-the-mainstream research; b) how to deal
with the possible proximity to lunatic fringe ideas; c) how to ensure
scientific rigor. Usage of social networking – now rapidly emerging in
the internet – within these approaches and its potential benefits are
described. Reports on first real-life experiences regarding both the
Interstellar Bet and Crazy Ideas will be presented. I discuss other
possibilities for fostering ideas and unconventional thinking briefly
in the context of interstellar space flight as well, including prize
contests.
Kelvin Long: Inertial Confinement Fusion & Antimatter Catalyzed Fusion for Space Propulsion 6.58 Mb
Abstract: It is well
known that conventional space propulsion schemes are inadequate for
longer term missions to the outer solar system and nearby stars. Fusion
propulsion is a technology that is both appropriate for such missions
and may be available within decades. In this paper we will discuss the
physics relevant to fusion based propulsion and the prospects for this
technology reaching technological maturity in the near future. Some
historical theoretical projects that included fusion based propulsion
will be discussed, such as Daedalus, Longshot and Vista. Finally, the
topic of antimatter catalyzed fusion will be discussed and whether this
offers potential performance gains to a fusion based drive.
Mike McCulloch: The Possibility of Inertial Reduction for Interstellar Travel
Abstract: The Pioneer and
flyby anomalies are well-observed unbound spacecraft trajectories that
seem to disagree with known physics. It is shown here that these
anomalies can be fairly well reproduced using a model that assumes that
inertia is caused by Unruh radiation and reduces in a new way as
accelerations become very small because of a Hubble-scale Casimir
effect. The model requires more testing (some experiments will be
suggested) and it is unclear why it should only apply to unbound
orbits, but it implies that 1) the inertial mass of interstellar craft
may be lower than expected, Pioneer 10 & 11 being the first
examples of this, and 2) it may be possible to further reduce the
inertial mass of such craft by bending Unruh radiation around them,
perhaps using the metamaterial cloaks recently developed, producing
greater acceleration for a given external force.
Remo Garattini: The Use of Casimir Energy for Traversable Wormholes: A Tool for Interstellar Travel
Abstract: Traversable
Wormholes provide an interesting tool for interstellar travel. They
represent Space Time tunnels connecting far points in the universe or
even two different universes. Unfortunately, their existence and
stability is related to the existence of a very particular form of
energy known as ‘’Exotic Matter’’ which has the unpleasant feature of
being negative. Despite of this difficulty, there exists a known form
of energy that appears to be a good candidate for playing the role of
the Exotic Matter, namely Casimir Energy. The study of Casimir Energy
is well known in QED phenomena, but it has obtained a growing interest
in various fields of physics and technology, especially in the
nanotechnology devices where it appears that this effect be relevant.
Luca Derosa: Relativistic Engineering for Interstellar Missions
Abstract: This
presentation takes into account the problem of the relativistic space
engineering and some solutions with which to begin a more exhaustive
study are suggested. Results are shown of the study of some important
velocity profiles for a relativistic space mission (in special
relativity): uniform motion, hyperbolic motion, constant thrust motion
and negative exponential thrust motion. A study on the Lorentz
transformations of the main formulas used to study the reliability of
systems for six important distributions are presented: Weibull,
exponential, normal, lognormal, gamma, Gumbel. Some consideration
concerning advanced space propulsion is also presented and finally,
there is a discussion on the unsolved problem of temperature
transformation, comparing the main theories known.
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