I do not think we can do it yet,
but a true tractor beam certainly needs to first neutralize the fields
surrounding the object and then to somehow induce a directional field that
moves it. Our present theoretical
knowledge is too slight to tackle this yet and it may of course never be
practical. Again observations of UFOs
suggest that it is possible but not easy.
At least they are trying to characterize
the problem as a necessary first step in development.
It is astounding how most of the
imagined inventions of the past are appearing in serious attempts of creation. Star Trek took advantage of many such SF
ideas that now are truly happening or soon will be. We already have the cell phone and we
certainly could organize a medical diagnostic tool if we put our minds to it
even now.
Tractor beans are now on the
agenda and perhaps we can find a way to transport folks without dissolving
them. I do prefer wormholes.
NASA studying ways to make 'tractor beams' a reality
NASA Goddard laser experts (from left to right) Barry Coyle, Paul
Stysley and Demetrios Poulios have won NASA funding to study advanced
technologies for collecting extraterrestrial particle samples. Credit: NASA's Goddard Space Flight
Center , Debora McCallum
Tractor beams -- the ability to trap and move objects using laser light
-- are the stuff of science fiction, but a team of NASA scientists has won
funding to study the concept for remotely capturing planetary or atmospheric
particles and delivering them to a robotic rover or orbiting spacecraft for
analysis.
The NASA Office of the Chief Technologist (OCT) has awarded Principal
Investigator Paul Stysley and team members Demetrios Poulios and Barry Coyle at
NASA's Goddard Space Flight Center in Greenbelt, Md., $100,000 to study three
experimental methods for corralling particles and transporting them via laser light to an
instrument -- akin to a vacuum using suction to collect and transport dirt to a
canister or bag. Once delivered, an instrument would then characterize their
composition.
"Though a mainstay in science fiction, and Star Trek in particular,
laser-based trapping isn't fanciful or beyond current technological
know-how," Stysley said. The team has identified three different
approaches for transporting particles, as well as single molecules, viruses, ribonucleic acid, and
fully functioning cells, using the power of light.
"The original thought was that we could use tractor beams for
cleaning up orbital
debris," Stysley said. "But to pull something that huge would be
almost impossible -- at least now. That's when it bubbled up that perhaps we
could use the same approach for sample collection."
With the Phase-1 funding from OCT's recently reestablished NASA
Innovative Advanced Concepts (NIAC) program designed to spur the development of
"revolutionary" space technologies, the team will study the state of
the technology to determine which of the three techniques would apply best to
sample collection. OCT received hundreds of proposals, ultimately selecting
only 30 for initial funding.
Replace Current Sample-Collection Methods
Currently, NASA uses a variety of techniques to collect
extraterrestrial samples. With Stardust, a space probe launched
in 1999, the Agency used aerogel to gather samples as it flew through the coma
of comet Wild 2. A capsule returned the samples in 2006.
NASA's next rover to Mars, Curiosity, will drill and scoop samples from
the Martian surface and then carry out detailed analyses of the materials with
one of the rover's many onboard instruments, including the Goddard-built Sample
Analysis at Mars instrument suite.
Goddard technologists are studying different techniques for corralling
particles and transporting them via laser light to instruments on rovers and
orbiting spacecraft. Credit: Concept image courtesy Dr. Paul Stysley
"These techniques have proven to be largely successful, but they
are limited by high costs and limited range and sample rate," Stysley
said. "An optical–trapping system, on the other hand, could grab desired
molecules from the upper atmosphere on an orbiting spacecraft or trap them from
the ground or lower atmosphere from a lander. In other words, they could
continuously and remotely capture particles over a longer period of time, which
would enhance science goals and reduce mission risk."
Team to Study Three Approaches
One experimental approach the team plans to study -- the optical vortex
or "optical tweezers" method -- involves the use of two
counter-propagating beams of light. The resulting ring-like geometry confines
particles to the dark core of the overlapping beams. By alternately
strengthening or weakening the intensity of one of the light beams -- in effect
heating the air around the trapped particle -- researchers have shown in
laboratory testing that they can move the particle along the ring's center.
This technique, however, requires the presence of an atmosphere.
Another technique employs optical solenoid beams -- those whose intensity
peaks spiral around the axis of propagation. Testing has shown that the
approach can trap and exert a force that drives particles in the opposite
direction of the light-beam source. In other words, the particulate matter is
pulled back along the entire beam of light. Unlike the optical vortex method,
this technique relies solely on electromagnetic effects and could operate in a
space vacuum, making it ideal for studying the composition of materials on one
of the airless planetary moons, for example.
The third technique exists only on paper and has never been
demonstrated in the laboratory, Poulios said. It involves the use of a Bessel
beam. Normal laser beams when shined against a wall appear as a small point.
With Bessel beams, however, rings of light surround the central dot. In other
words, when seen straight on, the Bessel beam looks like the ripples
surrounding a pebble dropped in a pond. According to theory, the laser beam
could induce electric and magnetic fields in the path of an object. The spray
of light scattered forward by these fields could pull the object backward,
against the movement of the beam itself.
"We want to make sure we thoroughly understand these methods. We
have hope that one of these will work for our purposes," Coyle said.
"Once we select a technique, we will be in position to then formulate a
possible system" and compete for additional NIAC funding to advance the
technology to the next level of development. "We're at the starting gate
on this," Coyle added. "This is a new application that no one has
claimed yet."
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