[meteorite-list] Asteroid Deflection Research Center Established at Iowa State

From: Rob McCafferty <rob_mccafferty_at_meteoritecentral.com>
Date: Fri, 30 May 2008 01:31:41 -0700 (PDT)
Message-ID: <933300.86819.qm_at_web55215.mail.re4.yahoo.com>

Hmmm! This seems like a bad idea. Have they not seen Superman 2? hehe

--- On Thu, 5/29/08, Ron Baalke <baalke at zagami.jpl.nasa.gov> wrote:

> From: Ron Baalke <baalke at zagami.jpl.nasa.gov>
> Subject: [meteorite-list] Asteroid Deflection Research Center Established at Iowa State
> To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
> Date: Thursday, May 29, 2008, 10:52 PM
> http://www.scienceblog.com/cms/seeking-answers-asteroid-deflection-16559.html
>
>
> Seeking answers to asteroid deflection
> Science Blog
> May 28, 2008
>
> An Asteroid Deflection Research Center (ADRC) has been
> established on
> the Iowa State campus to bring researchers from around the
> world to
> develop asteroid deflection technologies. The center was
> signed into
> effect in April by the Office of the Executive Vice
> President and Provost.
>
> "In the early 1990s, scientists around the world
> initiated studies to
> assess and devise methods to prevent near-Earth objects
> from striking
> Earth," said Bong Wie, the Vance D. Coffman Chair
> Professor in Aerospace
> Engineering and director of the center. "However, it
> is now 2008, and
> there is no consensus on how to reliably deflect them in a
> timely
> manner," he noted.
>
> Wie, whose research expertise includes space vehicle
> dynamics and
> control, modeling and control of large space structures,
> and solar sail
> flight control system development and mission design,
> joined the Iowa
> State faculty last August. "I am very happy that
> Professor Bong Wie has
> joined the faculty at ISU," said Elizabeth Hoffman,
> executive vice
> president and provost. "His work on asteroid
> deflection is exciting and
> of great importance."
>
> The ADRC will host an International Symposium on Asteroid
> Deflection
> Technology in fall 2008. Scientists and engineers from
> NASA, the
> European Space Agency, academia, and the aerospace industry
> will be
> invited to the Iowa State campus to formulate a roadmap for
> developing
> asteroid deflection technologies.
>
> Despite the lack of an immediate threat from an asteroid
> strike,
> scientific evidence suggests the importance of researching
> preventive
> measures. Sixty-five million years ago, a six-mile-wide
> asteroid struck
> near the Yucatan Peninsula in Mexico and created the
> 106-mile-diameter
> Chicxulub Crater. Most scientists now believe that a global
> climate
> change caused by this asteroid impact may have led to the
> dinosaur
> extinction. Seventy-four million years ago, a smaller
> one-mile-wide
> asteroid struck in central Iowa, creating the Manson
> Crater. Now covered
> with soil, it is the largest crater in North America at
> more than 23
> miles across.
>
> Just 100 years ago, June 30, 1908, an asteroid or comet
> estimated at
> 100-200 feet in diameter exploded in the skies above
> Tunguska, Siberia.
> Known as the Tunguska Event, the explosion flattened trees
> and killed
> other vegetation over a 500,000-acre area. But if the
> explosion had
> occurred four hours later, it would have destroyed St.
> Petersburg or
> Moscow with an equivalent energy level of about 500
> Hiroshima nuclear bombs.
>
> The potential for such devastation has astronomers scanning
> the skies to
> find and track asteroids that pose a danger, and it has Wie
> initiating
> this concerted research effort now before any asteroids are
> discovered
> heading toward Earth.
>
> Last November, NASA reported 900 known potentially
> hazardous objects
> (PHOs), most of which are asteroids. PHOs are defined as
> objects larger
> than 492 feet in diameter whose trajectories bring them to
> within about
> 4.6 million miles of the Earth's orbit. NASA scientists
> estimate the
> total population of PHOs to be around 20,000.
> "However," Wie said, "the
> asteroid we have to worry about is the asteroid that we
> don't know."
>
> "Developing technologies that can be used to prevent
> or mitigate threats
> from asteroids while also advancing space exploration is a
> challenge we
> accept as we work to assure a high quality of life for
> future
> generations," said Mark J. Kushner, dean of Iowa
> State's College of
> Engineering. "This research center serves as an
> excellent opportunity to
> provide leadership on an issue that has worldwide
> implications."
>
> According to Tom Shih, professor and chair of aerospace
> engineering,
> "the potential for a major catastrophe created by an
> asteroid impacting
> Earth is very real. It is a matter of when, and humankind
> must be
> prepared for it. Our aerospace engineering department
> strongly supports
> Professor Bong Wie's effort in establishing this center
> to address the
> engineering and science issues of asteroid
> deflection."
>
> Both high-energy nuclear explosions and low-energy
> non-nuclear
> alternatives will be studied as deflection techniques. The
> nuclear
> approach, which is often assessed to be 10-100 times more
> effective than
> non-nuclear approaches as stated in NASA's 2007 report
> to Congress, will
> be researched to verify its effectiveness and determine its
> practical
> viability, according to Wie.
>
> "A 20-meter (66 feet) standoff distance is often
> mentioned in the
> literature for a maximum velocity change of a 1-kilometer
> (0.6 mile)
> asteroid. However, we have to determine how close the
> nuclear explosion
> must be to effectively change the orbital trajectories of
> asteroids of
> different types, sizes, and shapes," Wie explained.
> "We will develop
> high-fidelity physical models to reliably predict the
> velocity change
> and fragmentation caused by a nuclear standoff
> explosion."
>
> The non-nuclear alternatives include kinetic impactors and
> slow-pull
> gravity tractors. Wie, who has previously worked on solar
> sail
> technology as applied to asteroid deflection, will present
> his recent
> study, "Multiple gravity tractors in halo orbits for
> towing a target
> asteroid," at the American Institute of Aeronautics
> and Astronautics
> Astrodynamics Specialists Conference in August. His paper
> has been
> accepted for publication in the AIAA Journal of Guidance,
> Control, and
> Dynamics.
>
> The chances of having to use deflection technologies on an
> asteroid in
> the near future are admittedly remote. Scientists estimate
> the frequency
> of an extinction-class (6 miles in diameter or larger)
> object striking
> Earth as once every 50-100 million years, and for a
> 200-foot or larger
> object as once every 100-500 years.
>
> The technologies that will be developed, including
> precision orbital
> guidance and navigation and control, however, have other
> applications as
> well. These may include future advanced space vehicles that
> will carry
> astronauts to an asteroid or Mars and homeland security
> applications.
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Received on Fri 30 May 2008 04:31:41 AM PDT