Asteroid Threat : Defending Our Planet from Deadly Near-earth Objects (9781616149147) (23 page)

“Given the global nature of the consequences, it is unlikely that one country will decide on its own whether to take action,”
the document stated. “There must be international involvement in decision-making and in whatever actions are decided. Discussions on how these decisions will be made should begin while there is no specific threat. Principles and protocols for the process of communication and dissemination of information about potential impacts, and the implementation of necessary mitigation measures should be negotiated and agreed to at an international level. These protocols should identify roles and responsibilities of key players and include a means to notify governments and the public of all hazards of a regional or global nature.”

The mitigation measures were discussed on the second day, when those who made presentations again emphasized that the first requirement is knowing what the attacker is made of and then deciding whether slow-push or quick-impulse deflection would be most effective. It was put on the record that missions to do them have been worked out and could be tested.
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At least as early as 1995, the AIAA was calling for an accelerated search for asteroids and short-period comets and the development of plans to stop them. In a position paper called “Responding to the Potential Threat of a Near-Earth-Object Impact” issued that year, it quoted Rep. George E. Brown Jr. of California, the chairman of the Committee on Science, Space and Technology and a staunch space advocate, as telling the following to a congressional hearing on the NEO threat in March 1993:

If some day in the future we discover well in advance that an asteroid that is big enough to cause a mass extinction is going to hit the Earth, and then we alter the course of that asteroid so that it does not hit us, it will be one of the most important accomplishments in all of human history.

The position paper said that the AIAA strongly believed that Brown's statement was correct and concluded with a warning. “If some day an asteroid does strike the Earth, killing not only
the human race but millions of other species as well, and we could have prevented it but did not because of indecision, unbalanced priorities, imprecise risk definition and incomplete planning, then it will be the greatest abdication in all of human history not to use our gift of rational intellect and conscience to shepherd our own survival, and that of all life on Earth.”

That being the case, the paper recommended the immediate approval of a program to accelerate the discovery, identification, and characterization of NEOs. Congress approved it three years later, and it became the Spaceguard Survey. The paper also recommended that a study be undertaken immediately to examine various concepts of responding to collision threats in the next century. “In the future,” the AIAA concluded, “the U.S. should consider establishing an office for coordinating the U.S. response to this risk and should invite other nations to participate. The objective of this office is to provide the focal point for overall program management, planning and systems engineering, as well as coordinate delegated responsibilities regarding NEO detection, intercept, rendezvous, command and control systems and activities without international partners.”
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That office should be called the Department of Planetary Defense.

Meanwhile, where NASA is concerned, the proverbial handwriting is on the wall. Having had its manned space program suffer a setback by the retirement of the shuttles and the decision to abandon a return to the Moon, at least in the foreseeable future, and having successfully completed the Spaceguard Survey, the space agency has also come to believe that it has a serious role to play in planetary defense. It is working to find and inventory 90 percent of all NEOs 140 meters or larger by 2020 (within its existing and projected budgets). The space agency responded to
Defending Planet Earth: Near-Earth Object Surveys and Mitigation Hazards
, the National Research Council's 2010 report that described the situation and suggested mitigation possibilities, by reporting that it was already
taking “a significant role” in plans for dealing with the NEO hazard in the UN's Committee on Peaceful Uses of Outer Space and in the international planetary-defense conferences. That was appropriate, since NASA commissioned and paid for the NRC study. NASA accepts the generally agreed-upon stages of collision avoidance: slow push, kinetic impact and, if they fail, the use of a nuclear weapon.

Ironically, nuclear weapons, which have been associated with what former secretary of defense Robert McNamara called Mutual Assured Destruction, could in fact assure survival. Bong Wie, the director of the Asteroid Deflection Research Center at Iowa State University, studied responding to a threatening asteroid on relatively short notice, which is to say a year or so, and concluded that a nuclear explosion is probably the only way to stop a large one in so relatively short a time. He came up with a hypervelocity asteroid impact vehicle that would hit the asteroid so hard that a crater would be formed and then a follow-up mission would plant a nuclear “device” in the crater that would set off the most efficient subsurface explosion possible and force the thing off course.
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The International Academy of Astronautics (IAA), which was established in Stockholm in 1960 by the legendary rocket pioneer Theodore von Karman, along with others who were committed to expanding the space frontier (as they put it), became so concerned about the NEO problem that it, too, joined the fray by extending a series of information-sharing planetary-defense conferences to Los Angeles in 2004; Granada, Spain, in April 2009; Bucharest, Romania, in May 2011; and a fourth in Flagstaff, Arizona, in April 2013. The meeting in Flagstaff opened with a session on Chelyabinsk, which was described as a “wake-up call.” The IAA issued a white paper after Flagstaff that, like the AIAA and other groups, called for increased international cooperation and communication and the discovery, characterization, and movement of the NEO, as well as mitigation
and constant preparedness. It also called for paying closer attention to the smaller asteroids, upgrading the world's space radars, considering sending low-cost probes to size up asteroids, and performing a kinetic impactor flight demonstration—that is, clobbering an asteroid to see what happens.
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While Congress has generally been supportive of NASA missions, in July 2013 it came out against one that would send an unmanned spacecraft out to capture a small asteroid in 2021 or afterward for close examination because it was considered frivolous, at least by the science committee in the Republican-controlled House. It was the centerpiece of the Obama administration's space-exploration agenda, but the Republicans laid out a plan that called for the space agency to send astronauts back to the Moon, set up a base there, and then go to Mars (on the cheap, with less money than NASA requested), not “lasso” a seven-to-ten-meter rock. “A costly and complex distraction” is how Rep. Steven Palazzo of Mississippi described the mission. Some of his colleagues complained that it seemed far-fetched and poorly articulated and, getting to the point, that it would not advance America's bragging rights in space the way a return to the Moon would. They were in a distinct minority, though. Congress was generally supportive of programs that contribute to planetary defense, and it remains so.

Obama had asked NASA to find a way to send astronauts to an asteroid by 2025 and then to Mars. NASA readily accepted the assignment and noted that it would “protect our planet” from dangerous asteroids in addition to making strides in human spaceflight. In June, the month before the Republicans laid out their objections, the space agency showed how concerned it was about the NEO situation by announcing its Asteroid Grand Challenge in which individuals and organizations were invited to find asteroids that threaten Earth and propose ways to end the threat. The space agency later reported that it received more than four hundred responses, including
offers to help with a mission to capture an errant rock. And the profit motive in capturing one or more asteroids remained. At least two companies announced their intention to mine them for precious metals. But ultimately, even with the explosion over Chelyabinsk fresh in the lawmakers' minds, the asteroid and comet threat remained a formidable problem yet not as important as the manned program. A return of astronauts to the Moon and then striking out for Mars, even with a public that has largely lost interest in having people in space, still captivates the imagination of many who identify with human adventure, whereas the mundane business of preventing wandering rocks and chunks of dirty ice from hitting Earth seems almost irrelevant.
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Those who were aware of the danger, however, steadfastly believed that a real, workable, strategic plan, not theatrics and incessant hand-wringing, was required. NASA's Advisory Council Ad-Hoc Task Force on Planetary Defense was therefore created in 2010 to come up with a clear definition of what the NEO problem is and to devise a workable defensive scenario once and for all. It was cochaired by Rusty Schweickart, then of the B612 Foundation, and Thomas D. Jones, another former astronaut who was pedigreed as a Distinguished Eagle Scout and had a doctorate in planetary science from the University of Arizona, as well as four space shuttle missions to his credit (in addition to
Sky Walking: An Astronaut's Memoir
, a readable account of his career that made a good case for supplementing Earth's natural resources by mining asteroids, not shunning them). And there were five other luminaries on the planetary-defense task force: Clark Chapman; Donald K. Yeomans; Richard P. Binzel, a professor of planetary science at MIT; Lindley Johnson, then of NASA's Near-Earth Object Observation Program in Washington; and Brian Wilcox, a principal investigator of robotic-vehicle development for planetary exploration at JPL, planetary exploration's home roost. The
group met in Cambridge, Massachusetts, in April 2010; it met again in Boulder, Colorado, that July; and members had two days of teleconferencing and Internet communication in August 2010 to discuss the planetary-defense situation and what NASA and the rest of the space community should do about it. The task force issued its final report on October 6–7, which recommended the following for the space agency:
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• Establish an organizational element to focus on the issues, activities, and budget necessary for effective planetary-defense planning, including a planetary-defense-coordination office, and challenge the international community to join analytical, operational, and decision-making activities. It recommended long-term, continuous monitoring of the NEO population and planetary-defense demonstration missions to be carried out for a decade at a cost of $250–$300 million annually, which would be one-sixtieth of the space agency's budget. Left unsaid, but clearly implied, was the fact that given the stakes, it would be a pittance.
  
• Acquire essential search, tracking, and warning capabilities for the early detection of potential NEO impactors and for tracking them with adequate precision with a space-based infrared telescope and investigate the development of low-cost, short-term impact warning systems.
  
• Investigate the nature of the impact threat, and specifically the physical characteristics of NEOs that most directly relate to planetary defense; that is, knowing the enemy in order to be able to stop it. That could entail deploying an infrared telescope in a Venus-like orbit, which would, in effect, allow the defensive unit to survey Earth's immediate neighborhood at a distance to provide as much warning time as possible of an impactor.
  
• Prepare an adequate response to the range of potential
  impact scenarios, including testing innovative deflection technologies in space, assist agencies that are responsible for civil defense and disaster response, research ways to stop NEOs with nuclear and other weapons, and deflect them.
  
• Provide leadership for the government to address planetary-defense issues with other agencies, in public education, in the news media, and in international forums; to support research in the physical, environmental, and social consequences of a range of attack scenarios; and, with other relevant agencies, to develop a planetary-defense communication plan.
  

David Morrison heartily agrees. “For the non-science policy maker, the impact hazard is a complex problem featuring the interactions of physical, technical, and social systems under conditions of great uncertainty,” he has written. “Communications are key, since in the end it is society's perception and evaluation of the hazard that are likely to determine what social and economic resources are applied. Policy makers will be dealing implicitly with the costs of action vs. the costs of inaction. From their perspective, even such an ‘innocent' first step as the Spaceguard Survey may have substantial social or political costs—for example if frequent ‘false alarms' persuade the public that scientists are incompetent and are squandering public funds, or if the existence of a survey triggers public demand for more expensive defense systems that decision makers are not prepared to provide.”
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While the first small steps are being taken by space agencies to stop dangerous asteroids and comets, Morrison has explained, “we are a long way from the technology to deflect an asteroid, especially one potentially threatening to civilization. However, it seems reasonable to expect that if such a large asteroid is discovered, one whose impact could kill a billion
people, the spacefaring nations would find a way to deflect it and save the planet. Given such a specific threat, almost any level of expense could be justified. This effort would represent the largest and most important technological challenge ever faced; whether it met with success or failure, world civilization would be forever changed.”
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Given what is at stake, the ultimate Strategic Defense Initiative to defeat impactors as an integral component of an international planetary-defense system should therefore be a top priority for the world community and would obviously be worth any level of expense.