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

by William E. Burrows

  The paper also suggested that the technology that was developed for US and Soviet space programs (it specifically mentioned the Strategic Defense Initiative) be studied for use against asteroids, although they would be used at far greater distances than they would have been to intercept ballistic missiles. The distance factor would be particularly important if the asteroid-busters are nuclear, which will most likely be the case (more about that further on). Even though it was published when the “giggle factor” was occurring in films and in other media, as was described in the fourth chapter, the paper was referred to more than two thousand times by 1993, making it the most cited AIAA position paper to that time.28 It was followed by one in 1995 that made the same recommendations and that was very likely responsible, at least in part, for the creation of the Near-Earth Object Program Office.

  The association took matters a giant step further when it held the first Planetary Defense Conference: Protecting Earth from Asteroids, in Anaheim, California, on February 23–26, 2004. The meeting was historically important because it was an incubator in which most of planetary defense's nationally recognized stalwarts convened for the first time to present their work and get acquainted in a synergistic atmosphere. The participants included Andrea Carusi of the European Space Agency; Clark Chapman; Lindley N. Johnson of the Planetary Science Institute; John Logsdon of George Washington University; Ed Lu; Rusty Schweickart, then of the B612 Foundation; David Morrison, an astrophysicist and the director of space at the NASA Ames Research Center; Steven J. Ostro, a radar astronomer at JPL who was part of the team that discovered 222 NEAs, 130 of them that were potentially hazardous; Donald K. Yeomans; and Simon P. Worden, a retired air force brigadier general and a research professor of astronomy at the University of Arizona, who was a congressional fellow.

  The meeting produced a white paper that summarized its conclusions, including recommendations to review international professional and amateur efforts to detect potentially threatening asteroids and comets and improve coordination—communication—among them, survey and catalog NEOs in the one-hundred-meter class, encourage the development of creative ideas for finding and cataloging potentially threatening long-period comets, develop and fund ground-based observation techniques and missions to the asteroids themselves, and establish a formal procedure for getting information out when the probability of an impact exceeds specified thresholds.

  “This conference is the first of a series of the threat posed by Near Earth Objects, possible techniques and missions for deflecting an oncoming object, and political, policy and disaster-preparedness issues associated with NEO deflection,” the paper said in summary. “The conference produced several recommended actions, the foremost being that we need to: 1) begin trust-building efforts so that claims that the NEO hazard is important will be considered credible by the public, even though we recognize that the probability of a disastrous impact is small; 2) increase our efforts to detect threatening objects and to determine the detailed physical and compositional properties of NEOs; and 3) move forward on means to deflect a threatening object. A key recommendation, consistent with previous AIAA Position Papers, is that a chain of responsibility be clearly and publicly defined for detecting and warning the public of threats, and mitigating those threats. These threats are real, and efforts to coordinate information and activities related to detecting and mitigating them should begin now…. Future impacts by comets and asteroids are a certainty,” the paper concluded. “Such impacts could have severe consequences—even ending civilization and humanity's existence. Life on Earth has evolved to the point where we can mount a defense against these threats. It is time to take deliberate steps to assure a successful defensive effort, should the need arise.”29 It is indeed time.

  The gravity of the situation…impelled the AIAA to hold a second Planetary Defense Conference from March 5–8, 2007, that one at George Washington University in the nation's capital, very likely with the hope that it would draw reporters from the Washington Post and the New York Times and, in the process, get some attention on Capitol Hill. That meeting also focused on detecting, characterizing, and mitigating NEOs, and there were also presentations and discussions on the political, legal, and societal challenges that would affect mounting a defense. As was the custom, the first day was, for the most part, spent describing the situation, including defining PHOs—potentially hazardous objects—that are fifty meters or larger and describing them. The second day was devoted to techniques that could be used to deflect them or hit them head-on, breaking them into small fragments. The third day was about the likely consequences of impacts, such as tsunamis and overpressure from airbursts. A panel also considered legal issues that would arise in the testing and implementing of deflection, along with that, it considered ways to maintain funding for planetary protection. The last day was spent discussing the international decision-making process, which would necessarily depend on developing a working relationship within the international community and a consensus on what needs to be done.

  “While significant scientific and technological advances have been made since the 2004 conference and are ongoing,” the concluding statement said, “it is clear that providing effective planetary defense from Near Earth Objects and planning for mitigation of an impact are in their infancy.” And the meeting's primary conclusions were articulated. The participants agreed with others who look for and are appropriately wary of NEOs that most civilization-ending, kilometer-size asteroids and comets have been located but that smaller ones in the 140- to 300-meter range could strike without warning and cause “serious loss of life and property over a broad area.” Earth-based radar antennas, such as the deep dish at Arecibo in Puerto Rico, are critical for providing the information that is needed for deflection which, the white paper noted, is still only in the conceptual phase. It also pointed out that there are serious technical and political issues, among others, in deciding whether and how to respond to a threatened impact and that a threat has never been seriously considered by any agency that would bear responsibility for dealing with it. Finally, the conference members went on record as noting, yet again, that the NEO threat is international and that it therefore demands international cooperation.

  “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.30

  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.”31 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.32

  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.33

  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.34

  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:35

  Establish an organizat
ional 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.