[FPSPACE] FW: NEO News (04/20/07) NASA Report to Congress
ljk4 at msn.com
Sat Apr 21 12:21:38 EDT 2007
>From: David Morrison <dmorrison at arc.nasa.gov>
>To: David Morrison <dmorrison at arc.nasa.gov>
>Subject: NEO News (04/20/07) NASA Report to Congress
>Date: Fri, 20 Apr 2007 14:11:57 -0700
>NEO News (04/20/07) NASA Report to Congress
>This edition of NEO News is devoted to the NASA "NEO Survey and Deflection:
>Analysis of Alternatives" report to Congress. Below are excerpts from the
>Congressional request, the transmittal letter from the NASA Administrator,
>the report summary, and some media responses.
>The full NASA NEO report (pdf) can be downloaded from these websites:
>From Section 321 of the NASA Authorization Act of 2005, the objectives of
>the NEO survey program are to detect, track, catalogue, and characterize
>the physical characteristics of NEOs equal to or larger than 140 meters in
>diameter with a perihelion distance of less than 1.3 AU, achieving 90
>percent completion within 15 years. NASA is directed to provide a report to
>Congress that provides: (1) an analysis of possible alternatives that NASA
>may employ to carry out the survey program of NEOs, including groundbased
>and spacebased alternatives with technical descriptions; (2) a recommended
>option; and (3) an analysis of possible alternatives that NASA could employ
>to divert an object on a likely collision course with Earth.
>From report transmittal letter, signed by Michael D. Griffin, NASA
>Administrator, dated March 7, 2007
> This is a complex issue, potentially involving many other U.S. Government
>agencies and international organizations ... I look forward to working with
>the Administration and Congress in setting realistic goals for a NEO survey
>program given the challenging demands already placed on NASA resources
>NASA recommends that the [current Spaceguard] program continue as currently
>planned, and we will also take advantage of opportunities using potential
>dual-use telescopes and spacecraft-and partner with other agencies as
>feasible-to attempt to achieve the legislated goal within 15 years.
>However, due to budget constraints, NASA cannot initiate a new program at
>Report on NEO Survey and Deflection: Analysis of Alternatives
>Section 321 of the NASA Authorization Act of 2005 (Public Law No. 109-155),
>also known as the George E. Brown, Jr. Near-Earth Object Survey Act,
>directs the NASA Administrator to transmit an initial report to Congress
>not later than one year after the date of enactment that provides: (1) an
>analysis of possible alternatives that NASA may employ to carry out the
>survey program of near-Earth Objects (NEO), including ground- based and
>space-based alternatives with technical descriptions; (2) a recommended
>option and proposed budget to carry out the survey program pursuant to the
>recommended option; and (3) an analysis of possible alternatives that NASA
>could employ to divert an object on a likely collision course with Earth.
>The objectives of the George E. Brown, Jr. NEO Survey Program are to
>detect, track, catalogue, and characterize the physical characteristics of
>NEOs equal to or larger than 140 meters in diameter with a perihelion
>distance of less than 1.3 AU (Astronomical Units) from the Sun, achieving
>90 percent completion of the survey within 15 years after enactment of the
>NASA Authorization Act of 2005. The Act was signed into law by President
>Bush on December 30, 2005.
>A study team, led by NASA's Office of Program Analysis and Evaluation
>(PA&E), conducted the analysis of alternatives with inputs from several
>other U.S. government agencies, international organizations, and
>representatives of private organizations. The team developed a range of
>possible options from public and private sources and then analyzed their
>capabilities and levels of performance including development schedules and
>Key Findings for the Survey Program:
> * The goal of the Survey Program should be modified to detect, track,
>catalogue, and characterize, by the end of 2020, 90 percent of all
>Potentially Hazardous Objects (PHOs) greater than 140 meters whose orbits
>pass within 0.05 AU of the Earth's orbit (as opposed to surveying for all
> * The Agency could achieve the specified goal of surveying for 90
>percent of the potentially hazardous NEOs by the end of 2020 by partnering
>with other government agencies on potential future optical ground-based
>observatories and building a dedicated NEO survey asset assuming the
>partners' potential ground assets come online by 2010 and 2014, and a
>dedicated asset by 2015.
> * Together, the two observatories potentially to be developed by other
>government agencies could complete 83 percent of the survey by 2020 if
>observing time at these observatories is shared with NASA's NEO Survey
> * New space-based infrared systems, combined with shared ground-based
>assets, could reduce the overall time to reach the 90 percent goal by at
>least three years. Space systems have additional benefits as well as costs
>and risks compared to ground-based alternatives.
> * Radar systems cannot contribute to the search for potentially
>hazardous objects, but may be used to rapidly refine tracking and to
>determine object sizes for a few NEOs of potentially high interest.
>Existing radar systems are currently oversubscribed by other missions.
> * Determining a NEO's mass and orbit is required to determine whether
>it represents a potential threat and to provide required information for
>most alternatives to mitigate such a threat. Beyond these parameters,
>characterization requirements and capabilities are tied directly to the
>mitigation strategy selected.
>Key Findings for Diverting a Potentially Hazardous Object (PHO):
>The study team assessed a series of approaches that could be used to divert
>a NEO potentially on a collision course with Earth. Nuclear explosives, as
>well as non-nuclear options, were assessed.
> * Nuclear standoff explosions are assessed to be 10-100 times more
>effective than the non-nuclear alternatives analyzed in this study. Other
>techniques involving the surface or subsurface use of nuclear explosives
>may be more efficient, but they run an increased risk of fracturing the
>target NEO. They also carry higher development and operations risks.
> * Non-nuclear kinetic impactors are the most mature approach and could
>be used in some deflection/mitigation scenarios, especially for NEOs that
>consist of a single small, solid body.
> * "Slow push" mitigation techniques are the most expensive, have the
>lowest level of technical readiness, and their ability to both travel to
>and divert a threatening NEO would be limited unless mission durations of
>many years to decades are possible.
> * 30-80 percent of potentially hazardous NEOs are in orbits that are
>beyond the capability of current or planned launch systems. Therefore,
>planetary gravity assist swingby trajectories or on-orbit assembly of
>modular propulsion systems may be needed to augment launch vehicle
>performance, if these objects need to be deflected.
>In response to the March 5-8 AIAA Planetary Defense Conference in
>Washington and the recent report to Congress from NASA concerning future
>NEO studies, several supportive stories have appeared in the press.
>FINDING DOOMSDAY ASTEROIDS
>New York Times Editorial
>Published: April 3, 2007
>How much effort should we expend to ward off the possibility that an
>asteroid might some day collide with Earth? Space experts attending a
>recent conference in Washington lamented the failure of the federal
>government - indeed, of the entire world - to take the threat seriously
>enough. The National Aeronautics and Space Administration, at virtually the
>same moment, advised Congress on steps that could be taken to find and
>divert threatening asteroids only to conclude that it couldn't afford them.
>That seems shortsighted. The risk is remote, but the consequences are
>potentially catastrophic. It would seem wise, at a minimum, to look harder
>for any death-dealing rocks that might menace us.
>The encouraging news is that the most horrendous hazards - asteroids like
>the one that wiped out the dinosaurs or even smaller objects whose impact
>could disrupt the global environment - have mostly been identified under a
>$4 million-a-year survey program. The space agency estimates that there are
>some 1,100 near-Earth objects whose diameters exceed six-tenths of a mile,
>big enough to destroy a medium-sized state and kick up enough dust to
>affect global climate and crop production. The survey has already
>identified more than 700 of them. None are on a path to collide with Earth.
>More troublesome is the threat of smaller asteroids, greater than 460 feet
>in diameter (about one-seventh the threshold of the really scary big ones),
>that could devastate a region but not the whole globe. NASA estimates that
>some 20,000 of these might be potentially hazardous; it has identified only
>a fraction of them. Two years ago Congress asked NASA to propose new search
>programs and to analyze ways to divert any asteroids on a collision course
>with Earth. The agency did that in a March report to Congress, but it
>balked at the notion of spending up to $1 billion or more to build search
>instruments or spacecraft.
>That is understandable. NASA is burdened with the need to finish the space
>station, build a successor to the shuttles, return to the moon and conduct
>wide-ranging research. It already has more jobs to perform than money to
>perform them. But finding asteroids that might threaten the planet, and
>studying their characteristics in the process, is probably more important
>than at least some of the other robotic missions mounted by NASA. Congress
>should either add funds to the agency's budget, or the agency should divert
>funds from other programs to accelerate the asteroid hunt.
>Developing ways to deflect asteroids is more problematic. NASA suggests
>that the best solution would be to explode a nuclear bomb next to an
>asteroid to deflect it off course, but international aversion to nuclear
>weapons in space would make that approach difficult without a global
>consensus. Other experts favor a high-speed ballistic impact or using the
>gravitational attraction of a hovering spacecraft to nudge the asteroid off
>course. Before plunging ahead with an asteroid-deflector, let's wait to see
>whether a real threat even exists.
>THE SKY IS FALLING. REALLY.
>By Russell L. Schweickart
>New York Times Op-Ed, March 16, 2007
>AMERICANS who read the papers or watch Jay Leno have been aware for some
>time now that there is a slim but real possibility - about 1 in 45,000 -
>that an 850-foot-long asteroid called Apophis could strike Earth with
>catastrophic consequences on April 13, 2036. What few probably realize is
>that there are thousands of other space objects that could hit us in the
>next century that could cause severe damage, if not total destruction.
>Last week two events in Washington - a conference on "planetary defense"
>held by the American Institute of Aeronautics and Astronautics, and the
>release by NASA of a report titled "Near-Earth Object Survey and Deflection
>Analysis of Alternatives" - gave us good news and bad on this front. On the
>promising side, scientists have a good grasp of the risks of a cosmic
>fender-bender, and have several ideas that could potentially stave off
>disaster. Unfortunately, the government doesn't seem to have any clear plan
>to put this expertise into action.
>In 1998, Congress gave NASA's Spaceguard Survey program a mandate of
>"discovering, tracking, cataloging and characterizing" 90 percent of the
>near-Earth objects larger than one kilometer (3,200 feet) wide by 2008. An
>object that size could devastate a small country and would probably destroy
>The consensus at the conference was that the initial survey is doing fairly
>well although it will probably not quite meet the 2008 goal. Realizing that
>there are many smaller but still terribly destructive asteroids out there,
>Congress has modified the Spaceguard goal to identify 90 percent of even
>smaller objects - 460 feet and larger - by 2020. This revised survey,
>giving us decades of early warning, will go a long way toward protecting
>life on the planet in the future.
>The good news is that scientists feel we have the technology to intercept
>and deflect many asteroids headed toward Earth. Basically, if we have early
>enough warning, a robotic space mission could slightly change the orbit of
>a dangerous asteroid so that it would subsequently miss the planet.
>Two potential deflection techniques appear to work nicely together - first
>we would deflect the asteroid with kinetic impact from a missile (that is,
>running into it); then we would use the slight pull of a "gravity tractor"
>- a satellite that would hover near the asteroid - to fine-tune its new
>trajectory to our liking. (In the case of an extremely large object,
>probably one in 100, the missile might have to contain a nuclear warhead.)
>To be effective, however, such missions would have to be launched 15 or
>even 30 years before a calculated impact.
>The bad news? While this all looks fine on paper, scientists haven't had a
>chance to try it in practice. And this is where NASA's report was supposed
>to come in. Congress directed the agency in 2005 to come up with a program,
>a budget to support it and an array of alternatives for preventing an
>But instead of coming up with a plan and budget to get the job done, the
>report bluntly stated that "due to current budget constraints, NASA cannot
>initiate a new program at this time." Representative Bart Gordon, Democrat
>of Tennessee, was right to say that "NASA's recommended approach isn't a
>credible plan" and that Congress expected "a more responsive approach"
>within the year.
>Why did the space agency drop the ball? Like all government departments, it
>fears the dreaded "unfunded mandate"; Congress has the habit of directing
>agencies to do something and then declining to give them the money to do
>so. This is understandable. But in this case, Congress not only directed
>NASA to provide it with a recommended program but also asked for the
>estimated budget to support it. It was a left-handed way for the Congress
>to say to NASA that this is our priority ... like it or not. But for some
>reason NASA seems to have opted for a federal form of civil disobedience.
>Another problem with the report was that, while it outlined other
>possibilities, it estimated that using a nuclear-armed missile to divert an
>asteroid would be "10 to 100 times more effective" than non-nuclear
>approaches. It is possible that in some cases - such as an asteroid greater
>than a third of a mile across - the nuclear option might be necessary. But
>for the overwhelming majority of potential deflection cases, using a
>nuclear warhead would be like a golfer swinging away with his driver to
>sink a three-foot putt; the bigger bang is not always better.
>Why the concern? First, even with good intentions, launching a
>nuclear-armed missile would violate the international agreements by which
>all weaponry is banned from space. Second, the laws of probability say we
>would be struck by such a large asteroid only once every 200,000 years -
>that's a long time to keep a standing arsenal of nuclear asteroid-blasters,
>and raises all sorts of possibilities of accidents or sabotage - the old
>"cure being worse than the disease" phenomenon.
>In the end, of course, this is not just America's problem, as an asteroid
>strike would be felt around the globe. The best course is international
>coordination on deflection technology, along with global agreements on what
>should be done if a collision looks likely. Along these lines, the
>Association of Space Explorers, a group of more than 300 people from 30
>nations who have flown in space (of which I am a member), is beginning a
>series of meetings in cooperation with the United Nations to work out the
>outlines of such an agreement.
>Still, as with many global issues, little will be accomplished unless the
>United States takes the lead. With the entire planet in the cross hairs,
>NASA can't be allowed to dither. If Congress's mandates and budget requests
>aren't energizing the agency, perhaps public hearings would shame it into
>Russell L. Schweickart, a former Apollo astronaut, is the chairman of the
>B612 Foundation, which promotes efforts to alter the orbits of asteroids.
>NASA SAYS CAN FIND MOST KILLER ASTEROIDS BY 2020 BUT LACKS THE MONEY
>International Herald Tribune, 5 March 2007
>The Associated Press
>WASHINGTON: NASA officials say the space agency is capable of finding
>almost every asteroid that might pose a devastating threat to Earth, but
>because it lacks the money to do it, the job will not get done.
>The cost to find at least 90 percent of the 20,000 potentially hazardous
>asteroids and comets by 2020 would be about $1 billion, according to a
>report NASA will release later this week. The report was previewed Monday
>at a Planetary Defense Conference in Washington.
>Congress asked NASA in 2005 to come up with a plan to track most killer
>asteroids and propose how to deflect the potentially catastrophic ones. "We
>know what to do; we just don't have the money," said Simon Worden, director
>of NASA's Ames Research Center. . . .
>The agency already is tracking larger objects, at least [1 km] in diameter,
>which could wipe out most life on Earth, much like what is theorized to
>have happened to dinosaurs 65 million years ago. Even that search, which
>has spotted 769 asteroids and comets - none on a course to hit Earth - is
>behind schedule. It is supposed to be completed by the end of next year.
>NASA needs to do more to locate other smaller, but still potentially
>dangerous space bodies. While an Italian observatory is doing some work,
>the United States is the only government with an asteroid-tracking program,
>One solution would be to build a new ground telescope solely for the
>asteroid hunt, and piggyback that use with other agencies' telescopes for a
>total of $800 million. Another would be to launch a space infrared
>telescope that could do the job faster for $1.1 billion, but NASA program
>scientist Lindley Johnson said NASA and the White House called both those
>choices too costly. A cheaper option would be simply to piggyback on other
>agencies' telescopes, a cost of about $300 million, also rejected, Johnson
>said. "The decision of the agency is we just can't do anything about it
>right now," he added.
>Earth got a scare in 2004, when initial readings suggested an 885-foot
>asteroid called 99942 Apophis seemed to have had a chance of hitting Earth
>in 2029. But more observations showed that would not happen. Scientists say
>there is 1 chance in 45,000 that it could hit in 2036. They think it would
>be most likely strike the Pacific Ocean, which would cause a tsunami on the
>U.S. West Coast the size of the devastating 2004 Indian Ocean wave.
>John Logsdon, space policy director at George Washington University, said a
>stepped-up search for such asteroids is needed. "You can't deflect them if
>you can't find them," Logsdon said. "And we can't find things that can
>cause massive damage."
>BUDGET DODGES KILLER ASTEROIDS
>National Public Radio, March 28, 2007
>Robert Reich (former Secretary of Labor)
>According to a new report from the National Aeronautics and Space
>Administration, some 100,000 asteroids and comets routinely pass between
>the Sun and the Earth's orbit. About 20,000 of these orbit close enough to
>us that they could one day hit the Earth and destroy a major city.
>But the worrying news is NASA believes over 1,000 of these things are large
>enough - about a mile wide in diameter - and their orbits close enough to
>us, as to pose a real potential hazard of crashing into the Earth with such
>force as to end most life on this planet. Scientists believe this is what
>killed off the dinosaurs about 65 million years ago.
>Congress has given NASA a budget of a little over $4 million a year to
>track these killer asteroids, but NASA says it needs at least a billion
>dollars more to find all of them by the year 2020. This might involve
>building a special observatory for tracking them and launching a spacecraft
>to observe the space around Earth from Venus.
>The job could be finished sooner than 2020, says NASA, but that would
>probably require a deep space orbiting infrared observatory, at an
>additional cost of $700 million.
>All of which raises at least three pertinent questions.
>First, if we're spending over a billion dollars a day in Iraq, why can't we
>bring the troops home a few days earlier and use the savings to track
>killer asteroids that might end life on Earth?
>And since we're talking about the survival of most living things and not
>just Americans, why shouldn't we expect other nations to kick in some
>money, too - especially now that the dollar is dropping relative to the
>euro and the yen?
>And third, once NASA knows for sure that a killer asteroid is heading
>directly for us, how exactly are we supposed to get ourselves out of its
>way, or it out of our way - and how much should we be budgeting to
>NEO News (now in its thirteenth year of distribution) is an informal
>compilation of news and opinion dealing with Near Earth Objects (NEOs) and
>their impacts. These opinions are the responsibility of the individual
>authors and do not represent the positions of NASA, the International
>Astronomical Union, or any other organization. To subscribe (or
>unsubscribe) contact dmorrison at arc.nasa.gov. For additional information,
>please see the website http://impact.arc.nasa.gov. If anyone wishes to copy
>or redistribute original material from these notes, fully or in part,
>please include this disclaimer.
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