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Advanced Propulsion Comes Of Age

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  • Bill Hamilton
    Advanced Propulsion Comes Of Age By Leonard David Senior Space Writer posted: 07:00 am ET 22 May 2002 NASA is known worldwide for routinely putting people into
    Message 1 of 2 , May 22, 2002
      Advanced Propulsion Comes Of Age

      By Leonard David
      Senior Space Writer
      posted: 07:00 am ET
      22 May 2002


      NASA is known worldwide for routinely putting people into Earth orbit. The
      agency is also revered as the only organization that has flung humans at
      escape velocity speeds to the Moon. However, NASA could also be known as an
      agency that's going nowhere fast.


      SIDEBAR
      The Earth has a magnetosphere, produced by the terrestrial magnetic field
      and plasma from the ionization of the upper layers of the atmosphere. The
      M2P2 will parallel these naturally occurring systems by creating an
      electromagnetic bubble or mini-magnetosphere around the spacecraft. Credit:
      Robert Winglee. Click to enlarge.
      See:
      http://www.space.com/businesstechnology/technology/advanced_propulsion_020522-1.html


      Mini-Magnetospheric Plasma Propulsion (M2P2) is an advanced plasma
      propulsion system that will enable spacecraft to attain unprecedented
      speeds, with minimal energy and mass requirements. This rendering depicts a
      mini-magnetosphere deployed around a spacecraft. Plasma or ionized gas is
      trapped on the magnetic field lines generated onboard, and this plasma
      inflates the magnetic field much like hot air in a balloon. Photo courtesy:
      R. M. Winglee, Univ. of Washington

      Even NASA's new chief, Sean O'Keefe, is keen about the need for speed. The
      agency is stuck in slow gear, he gripes, scooting about in spacecraft today
      at velocities not much greater than when John Glenn first sped into Earth
      orbit over 40 years ago.

      To help put some "momentum" into NASA, the agency is pushing forward on a
      nuclear propulsion and power initiative. Welcome news in contrast to the
      past. Over the years, NASA's advanced propulsion agenda has done little but
      advance in age.

      Fits and starts of funding have dogged NASA's quest for advanced space
      propulsion. Hoped for high-tech concepts have come and gone. Nuclear
      thermal, ion, magnetic, and chemical systems to antimatter, solar sailing or
      laser propulsion - converting these concepts and others from paper studies
      to reality has proven elusive. But that may change given a spurt of money
      for several types of advanced space propulsion.

      Wish list

      To open up the solar system to vigorous robotic and future human
      exploration, new forms of space propulsion are being sought. Not only are
      faster trip times to select targets made possible. Advanced propulsion
      allows more exhaustive, long-term surveys of planets and their moons, as
      well as comets, asteroids, and other bodies.

      NASA has kick-started an In-Space Transportation Investment Area effort.
      This new endeavor embraces a wish-list of high, medium, and low priority
      technologies, evolved from a space agency-wide look last year that focused
      on advanced missions over the next 10 to 15 years. Better yet, there is
      money now targeted to boost wish-list technologies into being.

      NASA's Marshall Space Flight Center, Huntsville, Alabama, is leading the
      In-Space Transportation investment work -- spread out through the NASA
      research network --. They are spearheading the endeavor for the space
      agency's Office of Space Science in Washington, D.C.

      "I think we've got a real chance here," said Les Johnson, the implementation
      manager for the advanced propulsion work. "We're trying to take the things
      people have talked about for years, but get sustained commitment to go make
      them happen," he told SPACE.com.

      Making them happen, Johnson added, means maturing propulsion ideas to a
      technology readiness level just short of actual flight.

      High-priority in-space propulsion technologies include:

      Aerocapture: Using a planet's atmosphere to slow a spacecraft. A vehicle
      built for aerocapture can slip into orbit in one pass through an atmosphere.
      No need for on-board propulsion. This saves mass and permits use of a
      smaller, less-expensive launcher. These technique gets a vehicle to a
      destination quickly, hastening start-up of science operations;

      Next Generation Electric Propulsion: Improve the performance of this
      technology, from ion engines to fission propulsion drives. High-throughput,
      lightweight, and more powerful ion engines, for example, enable a host of
      future space missions, including a Europa Lander, a Saturn Ring Observer, a
      Neptune Orbiter, and a Venus Surface Sample Return probe; and

      Solar Sails: Strong, lightweight composite materials fashioned into a large
      sail. Requiring no fuel, a solar sail relies on the steady push of photons
      from the Sun. A major challenge is how best to unfurl a thin sail in space,
      then control its direction. Sail propulsion is seen as the way to launch an
      interstellar precursor mission in the next decade.
      Go fly status

      Johnson said by combing the work of NASA centers with industry and academia,
      these high priority technologies and others -- particularly, nuclear
      electric propulsion -- will be moved up in technological readiness for
      flight in space.

      "We want to get these technologies to the point that everything that can be
      done on the ground has been done�and they are ready to go fly," Johnson
      said. NASA calls this pre-flight status as Technological Readiness 6 or
      TR-6.

      No single propulsion scheme fits all needs.

      For instance, in some cases, rapid trip time is not as critical, contrasted
      to more payloads delivered to the target. "That's why we're investing in
      more than one technology�because there's no one answer for everything," he
      said.

      Plasma balloon

      Inside and outside NASA, a range of promising propulsion schemes being
      pursued.

      One intriguing prospect is a propellantless propulsion concept tagged by
      some as a plasma sail. The scheme is the brainchild of Robert Winglee, a
      scientist at the University of Washington in Seattle.

      His Mini-Magnetosphere Plasma Propulsion, or M2P2 for short, takes advantage
      of the natural environment of space. M2P2 technology creates a huge magnetic
      bubble around an interplanetary craft. In deploying the mini-magnetosphere,
      this plasma "balloon" interacts with high-speed ionized particles shed by
      the Sun that, in turn, push the vehicle through space.

      "The technology seeks to do what space does -- deploy a magnetized sail to
      travel with the winds," Winglee said. Plasma sail technologies could cut
      conventional trip times to the outer planets in half. The NASA Institute for
      Advanced Concepts (NIAC) funded early work on Winglee's M2P2 notion.

      A new test chamber at the university, Winglee said, has proven helpful in
      exploring the intricacies of creating a plasma balloon. "We're very happy
      with the results to date that we are seeing�very similar to computer
      simulations. That's a great relief, actually," he said.

      If the flow of funding continues full-throttle, Winglee feels the plasma
      sail can be pushed to the NASA TR-6 level. Ultimately, the concept's
      enhanced thrust could be tested in some sort of geosynchronous orbit, he
      said.

      VASIMR mode

      Meanwhile, at NASA's Johnson Space Center (JSC) in Houston, Texas, lab work
      continues on the Variable Specific Impulse Magneto-plasma Rocket.

      Better known as the VASIMR, this technology could result in shorter trip
      times to the planets than now available, made possible by varying the
      rocket's specific impulse. It can be operated in a mode that maximizes
      propellant efficiency or a mode that maximizes thrust, reported Andrew Petro
      at an aerospace gathering this past January.

      Petro, a JSC spacecraft engineer, and astronaut Franklin Chang-Diaz are part
      of a team of advanced space propulsion experts engaged in shaping a proposed
      test of the rocket on the International Space Station (ISS).

      The ISS experiment would show the prototype engine's ability to help negate
      electrical charging on the outpost and also counter drag forces that act on
      the orbiting facility.

      "This experiment will provide an opportunity to demonstrate the performance
      of the rocket in space and measure the induced environment," Petro reported.

      In for a fling?

      One advanced space transportation technology is tether-based propulsion.

      A NASA team, including the University of Illinois at Urbana-Champaign,
      Tennessee Technological University in Cookeville, and Tethers Unlimited of
      Lynnwood, Washington are developing the Momentum Exchange, Electrodynamic
      Reboost (MXER) tether. This spinning, tether-based satellite in low Earth
      orbit would snare slower-moving objects and toss them at increased speed
      toward higher orbits.

      This idea is akin to two ice skaters that "crack the whip" - launching one
      another at high speed across the ice.

      By briefly linking a slow-moving object with a faster one the slower
      object's speed may be dramatically increased as some of its counterpart's
      momentum is transferred between the two.

      MXER follow-on work could pave the way for chucking payloads beyond
      low-Earth orbit, perhaps paving the way for a human return to the Moon or
      flinging cargo and crew outward toward the distant dunes of Mars.

      Glow, and still go

      The arena of laser propulsion continues to bloom, said Leik Myrabo, CEO of
      Lightcraft Technologies, Inc., headquartered in Bennington, Vermont. He
      predicts a revolution in low-cost access to space, and actively promotes the
      use of beamed energy propulsion to accelerate vehicles called Lightcraft
      into orbit for a fraction of the cost it currently takes to get any object
      into space.

      Recent experiments, Myrabo said, have centered what heat-thwarting materials
      can be applied to the ceramic engine of a Lightcraft. Engine coatings must
      take the ferocious high temperature environment that laser propulsion
      produce, permitting a Lightcraft to "glow, and still go," he said.

      The first national workshop on laser propulsion is slated for this November
      in Huntsville, Alabama, Myrabo said, organized to transform the embryonic
      work on laser propulsion technology into real space transportation systems
      of the future, he said.

      If you want an uplifting view of laser propulsion ask Tom Meyer of the
      Boulder Center for Science and Policy in Colorado. He has led a study team
      on the feasibility of building a laser elevator, reporting their findings
      recently in the Journal of Spacecraft and Rockets, a publication of the
      American Institute of Aeronautics and Astronautics (AIAA).

      "The laser elevator works much like a lift in a garage, raised by a piston.
      But in this case, the piston is replaced by an intense beam of light that
      recycles between a spacecraft-mounted mirror and a mirror fixed to the laser
      source," Meyer said.

      This laser elevator requires technology that is not too distant from the
      current state-of-the-art, Meyer said. Once developed, such propulsion
      hardware could rapidly deploy a lightsail to scrutinize a threatening
      asteroid or comet. Also studied was using the recirculating beam system to
      launch a probe to Pluto, reaching that far-away world in about 6.5 years, he
      said.

      Space drive

      Leave no stone unturned is seemingly a propulsion ploy of NASA's Glenn
      Research Center in Cleveland, Ohio. This center is home for the Breakthrough
      Propulsion Physics Project.

      All manner of "exotic" research is ongoing. That includes delving into
      transient inertia effects, quantum vacuum energy, zero-point electromagnetic
      energy and Casimir forces, or exploring anomalous superconductor gravity
      effects and superluminal quantum tunneling.

      In short, any near-term success in any of these areas might foster the space
      drives of tomorrow.

      "We're basically on a steady course, albeit running at the slow pace typical
      of such small projects. Our work is presently operating at a funding level
      of about a half-million dollars per year," said NASA's Marc Millis who
      manages the effort.

      Millis said that a significant step for the project took place in January of
      this year. A Breakthrough Propulsion Physics Research Consortium has been
      established via a cooperative agreement with the Ohio Aerospace Institute.

      "This research consortium will reach out to geographically dispersed
      researchers to find, support, and coordinate the best research to make
      credible progress toward the visionary goals we have, and to disseminate the
      results for the benefit of all," Millis said.

      Destination anywhere

      While there is no shortage of interesting advanced propulsion designs, many
      proposals could remain in the realm of visionary speculation. What is needed
      is commitment and doses of research dollars and lab time to bring them into
      being.

      "NASA has to do things differently in the future," explains NASA chief, Sean
      O'Keefe. "One of the major obstacles of deep space travel is finding fast
      and efficient ways to get around�to get to anywhere."

      "Conventional rockets and fuel simply aren't practical as we reach further
      out into the cosmos," O'Keefe notes. "If we're going to pioneer the future
      as only NASA can, we're going to need new ways to get us there," he
      concludes.
      --------------------------------------------------------------
      Wanna go for a ride?



      Bill Hamilton
      Executive Director
      Skywatch International, Inc.
      websites:
      http://home.earthlink.net/~skywatcher22
      http://home.earthlink.net/~skywatcher12
      http://home.earthlink.net/~xplorerx
      http://home.earthlink.net/~xplorerx2
      http://home.earthlink.net/~xplorerx3
      Fiat Lux et Veritas


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    • Joseph Hiddink
      Sorry, but none of the mentioned systems will ever really be of any importance for Real Space Travel Guess why they never looked in the One Terminal Capacitor
      Message 2 of 2 , May 22, 2002
        Sorry, but none of the mentioned systems will
        ever really be of any importance for Real Space
        Travel
        Guess why they never looked in the One Terminal
        Capacitor System.
        Too inexpensive, it will make rockets and
        multi-billion nuclear reactors obsolete, reaching
        the Moon in a few hours or Mars in one day will
        do harm to the economy, like the Barf-Bag
        Manufacturers and the Doctors who specialize in
        ostoporosis....--
        Tried to contact Nasa many times, "Too busy to
        answer e-mail" (Millis)
        Maybe it should go to another country.
        Joseph Hiddink vliegschotel@...

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