Read Asteroid Threat : Defending Our Planet from Deadly Near-earth Objects (9781616149147) Online
Authors: William E. Burrows
Apollo's end left NASA in a quandary. Although it ran many routine satellite operations that provided weather, communication, and navigation information that had become indispensable to a modern society, Apollo was by far its greatest, most ennobling achievement, and it was now history. Next in order of prestige and public awareness was the exploration of the Solar System, which had started with the Ranger and Surveyor projects scouting the Moon in preparation for Apollo, and then it extended to the Mariner missions to Mercury, Venus, and Mars; the Pioneer missions to Jupiter and Saturn and to investigate solar phenomena; the landing of two Viking spacecraft on Mars; the Voyagers' sensational Grand Tour; Magellan's mapping of Venus; and Galileo's intense reexamination of the King of the Planets. The “take” from the science missions was phenomenal and ranks with the exploration of Earth itself in the eighteenth and nineteenth centuries. But the accumulation of all the information, together with budget cuts because of priorities at home, eventually brought Solar System exploration to near closure as well. The same for the International Space Station, which, because of the retirement of the shuttles, Americans can reach only by paying Russiaâwhich “lost” the
space race (whatever that was)âto transport them in
Soyuz
spacecraft. And with the days of Chuck Yeager and his X-1, followed by the extraordinary X-15, long gone, aeronautical testing is routinely going on but is negligible. That leaves NASA without a major mission. But there is one: planetary defense.
The agency without a major mission employs some eighteen thousand people in its Washington headquarters and in ten field centers spread around the country, most notably at the John F. Kennedy Space Center on Florida's east coast, which used to be Cape Canaveral, and which has launched all civilian missions, human and robotic, since the space program began. The Lyndon B. Johnson Space Center in Houston is the human-spaceflight center. In keeping with the state's outsized reputation, it is a complex that consists of one hundred buildings on 1,620 acres and trains US astronauts and other nations' spacefarers. The George C. Marshall Space Flight Center at the Redstone Arsenal in Huntsville, Alabama, where von Braun presided and where the
Saturn V
was therefore built, is where the shuttle was designed and produced, as well as the International Space Station. The John H. Glenn Research Center in Cleveland does what its name says: it researches advanced technology for both air-breathing and rocket systems. JPL, the Jet Propulsion Laboratory, in Pasadena, ran the Voyager and other Solar Systemâexploration missions, including those Ranger and Surveyor landings that scouted the lunar surface in preparation for Armstrong, Aldrin, Collins, and the eighteen astronauts who followed them. And the Ames Research Center at Moffett Field in California, to take one more, did fundamental research on robotic lunar exploration and now does it on spaceflight, information technology, and, what is most relevant to planetary defense, on the objects that prowl around the neighborhood. NASA also runs the Deep Space Network (DSN), which operates large, movable, parabolic radar antennas in Goldstone, California; at a site west of Madrid; and at Canberra, Australia,
that watch the sky in all directions. (The network is described in the
next chapter
: “The Ultimate Strategic Defense Initiative.”)
With the overriding demands of the manned program effectively over and Solar System exploration now marginal, the space agency's considerable human and physical resources ought to be engaged in protecting Earth from near-Earth objects (NEOs) as its highly focused, central mission; its chief raison d'être. That is not to say that other programs should be abandoned. We must go on exploring, not only to expand our presence in the universe, but also to increase the knowledge that defines us. And obviously NASA's routine but imperative services must continue. But Annalee Newitz, a science writer and the author of
Scatter, Adapt, and Remember: How Humans Will Survive a Mass Extinction
, got it right when she wrote that “today, we have evidence that confirms environmental changes like these [the widespread devastation caused by a major impact] can be blamed directly or indirectly for most mass extinctions that have scourged the Earth. And that's why our space program isn't just something educational we're doing to learn more about the universe. It's vital to our survival as a species, because the Earth isn't going to be a safe place for us in the long term.”
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Planetary defense is so important that it warrants being run by a separate, specialized organization within NASA, perhaps called the Department of Planetary Defense, whose staff would come not only from NASA but also from the four military services. Since the threat is worldwide, the DPD would work closely with those who are doing similar work in foreign space organizations and with the United Nations and NEOShield, an international planetary-defense group that was started in 2012 specifically to foster coordinated collective defense of the planet.
It is extremely important that the Department of Planetary Defense have a budget that is adequate to maintaining a serious program and that the necessarily long-term strategy it would adopt not be subject to the vagaries of congressional politics, particularly
as they would affect that budget. In that regard, the DPD would cooperate with foreign space agencies and NEOShield to the fullest extent possible and be flexible enough to adapt to useful suggestions, but as is the case with other US federal institutions such as the Defense Department, it would not be bound to obey their suggestions. The Defense Department is an American member of NATO, but it does not take orders from it.
The Department of Planetary Defense would also maintain liaison with the planetary-defense groups, such as the Planetary Defense Foundation and the B612 Foundation, as well as the national and international scientific establishments, because ideas are generated in those environments, often synergistically. The National Research Council's work in survey and mitigation strategy could benefit the DPD, for example, and so could a defensive system that consists of Rusty Schweickart and Ed Lu's three-phase planetary defenseâlocate and identify potential impactors, try to nudge them off course, and destroy them a long way out if nudging does not workâplus a last-ditch defense that uses specially adapted technology from the ill-fated (and ill-conceived) Strategic Defense Initiative, or Star Wars, scheme that was considered during the Reagan administration.
The weapons the Department of Planetary Defense and NEOShield could use to obliterate approaching NEOsâand that is precisely what they would be and should be called:
weapons
âare described in
chapter 7
. But weapons must be the last resort because, again, blowing up an asteroid that is relatively close and approaching at high velocity would turn it into fragments that could inflect terrible damage independently. The goal is to spot attackers so far ahead of impactâa decade or more is preferableâthat they can be gently nudged off course long before they have to be stopped with weapons because their threat is becoming immediate. That capability will obviously require an excellent long-range surveillance system that sees in all directions.
Intelligence is defined as the ability to learn and understand new situations, some of them extremely complicated, and to apply that knowledge to manipulate the environment to one's advantage. That especially applies to situations that are dangerous or potentially dangerous.
Avoiding danger is taken to be so imperative by most of the nations in this world that they have created special organizations whose purpose is to find anything that constitutes a danger to the security of the state and then reduce or eliminate it. Having effective intelligenceâknowing precisely what is going on beyond the nation-state's bordersâis therefore an integral part of the operation of every government in the world. Intelligence professionals hate surprises because they can cause terrible damage and devastating defeat. The rule is therefore to know as much as possible about what is happening in one's environment (or one's space, as it is now appropriately called) all the time. It is broadly known as situational awareness, and it began in the caves, continued to the city-states, then to nations, and, as the world coalesced in the twentieth century, to this planet as a whole. The landings on the Moonâextending humanity to another world in the great tradition of explorationâwas ennobling. The imagery taken of Earth showed a beautiful solitary planet, an oasis of life, slowly rotating in black space and, seen against the airless void that surrounds it, made it clear that its creatures are entirely dependent on it for their survival and that
it is fragile, vulnerable, and perishable. Some of the rocks that speed by constitute a threat, as the craters both on Earth and on the body on which the astronauts stood taking pictures, clearly showed.
The US Space Surveillance Network was started in 1957 immediately after
Sputnik
went into orbit. It is a critical part of US Space Command's global presence and is responsible for detecting, identifying, tracking, and cataloging manmade objects orbiting Earth, including both active and inactive satellites, spent rockets, and debris that range in size from small chunks of broken satellites to entire rocket upper stages, to the International Space Station. The network scrutinizes space for reasons of national security, and that obviously means knowing what foreign spacecraft, civilian as well as military, are out there and what they are doing that could potentially threaten the national security of the United States.
But security in its broadest sense means freedom from dangerâsafetyâand it has a far larger dimension than the military “arena.” As is the case with individuals, safety means that the nation will not come to harm and that its well-being is assured to the greatest extent possible. Safety for the individual not only means that he or she will not be manhandled, mugged, or murdered, but also that he or she will not be killed by a lamp that is tossed out of a sixth-floor window or by an automobile that runs a red light through a crosswalk; in other words, be the victim of a fatal accident. It is the same with nations, where security not only requires that a country is safe from foreign military attack (and now terrorism), but that it also is safe from major attacks by nature. Defenses have therefore been put in place to increase the safety margin from natural disasters, which is why hurricanes and typhoons are tracked by imaging satellites and Caribbean hurricanes are penetrated by US Air Force Hurricane Hunters crews that fly into them to measure their intensity; the Richter scale is used to calculate the energy
released during an earthquake so scientists can gain information about them and are able to better predict their force; and icebergs and ice floes are monitored to avoid a repetition of the
Titanic
tragedy.
And national and international security, to carry the analogy further, have dimensions that go well beyond the sanctity of boundaries and air space, freedom of the seas, and limits on nuclear-weapons stockpiles. They also include safety from sudden, devastating attacks by nature. The most potentially dangerous of those attacks, as Gene Shoemaker said, could (and have) come from large (and not-so-large) objects flying near Earth at very high velocity. After prevention of a nuclear war, staying safe from asteroids and comets that could cause terrible death and destruction, if not humankind's extinction, has therefore been one of the world's most important priorities. And it did not take a Stephen Hawking, a Freeman Dyson, or a Richard Feynman to know that potential impactors could not be prevented from slamming into Earth unless their whereabouts were precisely known years before impact and their trajectories accurately established. That is why Congress ordered NASA to do the Spaceguard Survey in 1998 and have it completed by 2008.
But by then, the astronomers, astrophysicists, and others interested in the impact threat had already long been addressing it. They held an International Near-Earth Object Detection Workshop in Vail, Colorado, that began in May 1991 and ended in January 1992, conducted under NASA's auspices. The participants decided that wayward asteroids and comets are indeed a significant hazard to life and property and accepted the mantra that while the possibility of being hit by a large one is extremely small, the consequences of such a collision “are so catastrophic that it is prudent to assess the nature of the threat and prepare to deal with it.” The first step in preventing a catastrophe, the astronomers and others rightly decided, requires a
comprehensive search for Earth-crossers and a detailed analysis of their orbits. The workshop therefore produced a report that contained its deliberations on creating a program that would dramatically increase the detection rate of Earth-crossers.
Detecting “intruders” is one thing. What to do when it is determined that they are bearing down on Earth is another, and, appropriately, that subject came up at an interception workshop that was held at the Los Alamos National Laboratory in early 1992. Having determined what the threat was, the next logical step was to try to come up with ways to mitigate it. That meant devising ways to nudge potential impactors off course a decade, and ideally a couple of decades, ahead of time. (Everyone agreed that the Bruce Willis Defense, as shown in the film
Armageddon
, in which a comet is nuked a week or so before the collision, is great theater but abominable planetary defense since it would merely turn a cannonball into grapeshot, each chunk of which could destroy a city.) Edward “The Father of the H-Bomb” Teller and Lowell Wood nevertheless gave presentations that called for blasting them with nuclear weapons. That led to what many at the meeting called “the giggle factor,” according to Clark R. Chapman. Wood was an astrophysicist at the Lawrence Livermore National Laboratory in New Mexico, a disciple of Teller's, and the inventor of the nuclear-pumped x-ray laser, which was supposed to destroy Soviet ballistic missiles by hitting them with laser beams coming from nuclear explosions in the stratosphere as part of President Ronald W. Reagan's Strategic Defense Initiative (which is described further on).
“Many of the Department of Energy researchers who had been recently introduced to the question of how to deflect asteroids, were provided with a technically flawed analysis by Wood et al., arguing that there is great danger from very small asteroids that impact frequently; in fact, they burn up harmlessly in the Earth's atmosphere, never posing a danger to anyone on the ground,” Chapman has written. He continued:
Nevertheless, because of the Wood analysis, many of the analyses readied for presentation at Los Alamos concerned application of Strategic Defense Initiative (“Star Wars”) technology originally intended to shoot down enemy missiles, which aren't very different from Wood's cosmic bullets. Astronomers in the audience, including Morrison and myself, tried to explain that the small objects posed no significant hazard, and that it was the large (> 1.5 km diameter) objects that were of concern. Indeed, schemes
were
discussed at the Detection Workshop that would mitigate impact of the larger ones, including stand-off detonation of a neutron bomb, but also including outlandish “blue sky” ideas involving anti-matter and other notions more appropriate to science fiction novels.
Chapman so disagreed with using a Star Wars defense against near-Earth objects (NEOs) that he exercised the ancient prerogative of the coauthors of scholarly papers who disagree with their colleagues' conclusions. He asked that his name be omitted from the report, and, as custom required, his request was honored.
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The planetary-defense community, which had long understood the NEO threat and believed that learning as much as possible about it was imperative, held several international meetings during the last decade of the twentieth century and the first decade of the twenty-first and produced an impressive array of scrupulously detailed, highly specialized studies. (“Diogenes A: Diagnostic Observation of the Geology of Near-Earth Spectrally-Classified Asteroids” is one example among hundreds.)
The Association of Space Explorers International Panel on Asteroid Threat Mitigation decided in 2008 that, since the threat from NEOs is worldwide, the whole world should know about it and, if possible, get involvedâand that obviously included the United Nations. The association itself was formed in 1983 by a large group of the space community's leading lights, including several who had been to space. The fact that it had a twenty-five-member panel that worked on trying to reduce the threat
was a clear indication of how seriously its members took the problem. The panel also decided that it was important to alert the international community about the potential danger and the need to do something to protect the planet.
It therefore submitted a report,
Asteroid Threats: A Call for Global Response
, to the United Nations in September 2008. After providing the requisite background information, including Tunguska and 99943 Apophis, “which has a 1-in-45,000 chance of striking Earth in 2036,” and explaining that such events are infrequent in a human lifetime but can be devastating when they do occur, the panel reiterated what had long been known about the situation and made the case for an international response to it. “Because NEO impacts represent a global, long-term threat to the collective welfare of humanity, an international program and set of preparatory measures for action should be established. Once in place, these measures should enable the global community to identify a specific impact threat and decide on effective prevention or disaster responses. A global, coordinated response by the United Nations to the NEO impact hazard should ensure that three logical, necessary functions are performed,” the document stated.
The first function was information gathering, analysis, and warning, which, as everyone in the community had always agreed, meant knowing the enemy. The second dealt with mission planning and operations and called for a group having that title to assess the global capacity to deflect a hazardous NEO by specifying what technologies would be required and what the capabilities of participating space agencies had to be to deflect it. And lastly, the panel suggested that the United Nations oversee those functions with an intergovernmental Missions Authorization and Oversight Group, as it came to be known, that would develop policies and guidelines that represent the international will to respond to the threat and submit them to the UN Security Council. That presumed there was an
international will and that the international community would act cohesively to address the potential danger with a specific defensive plan. It was a stretch that was tantamount to getting the community to agree on the definition of responsible government or what constitutes great art.
“The Association of Space Explorers and its international Panel on Asteroid Threat Mitigation are confident that with a program for concerted action in place, the international community can prevent most future impacts,” the panel stated, carefully using the qualifier
most
. “The Association of Space Explorers and its international Panel are firmly convinced that if the international community fails to adopt an effective, internationally mandated program,” the document warned, “society will likely suffer the effects of some future cosmic disasterâintensified by the knowledge that loss of life, economic devastation, and long-lasting societal institutions could have been prevented. Scientific knowledge and existing international institutions, if harnessed today, offer society the means to avoid such a catastrophe. We cannot afford to shirk that responsibility.”
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The deliberative body deliberated for almost five years, and its Committee on the Peaceful Uses of Outer Space finally came up with Action Team 14, which issued a reportâironically, three days after Chelyabinskâthat called for international cooperation in the form of an International Asteroid Warning Network, an Impact Disaster Planning Advisory Group, and a Space Mission Planning Advisory Group. “If the proposed coordination mechanism was in place,” Sergio Camacho, the chairman of Action Team 14, said at a news conference in Vienna, “then at minimum it would have allowed for more observation and better understanding and education of the population on what to expect rather than having a surprise effect with people not knowing what was happening.”
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