Even though the risk of an accident is low, most of us arenâ€™t prepared to drive our cars without insurance. The consequences of an uninsured fender bender are too great. So we prudently spend a small amount of money to hedge our bets against an unlikely but real risk.
Former Apollo astronaut Russell L Schweickart, chairman of the B612 Foundation, makes a compelling case that we should apply the same logic to the small but real and potentially catastrophic risk of an asteroid collision with the Earth.
The prospect of just such a natural disaster from space was highlighted in December 2004, with the re-discovery of the Near-Earth Asteroid (NEA) 99942 Apophis. For a few days, while predictions of its path were still being refined, estimates of the risk that the 51 million ton space rock would strike the Earth reached 1 in 37. Further observations ruled out an impact, but on Friday, April 13th, 2029, the asteroid will pass within 20,000 miles of the Earthâ€™s surface. Thatâ€™s a very close shave in cosmic terms â€“ roughly the height at which communications satellites orbit.
A small chance remains, about 1 in 5500, of an impact during a later encounter in 2036 â€“ but thereâ€™s actually a higher probability of some as yet uncataloged object hitting us first. The vast majority of NEAs remain undiscovered. There is a survey currently under way to find all the Earth-crossing NEAs over a kilometer in size â€“ this will give a good understanding of the baseline threat from the estimated 1100 or so â€˜planet killerâ€™ asteroids. The Spaceguard survey is currently on target to have cataloged 90% of the NEAs of that size by 2008.
But thatâ€™s only a part of the risk. There are also an estimated 200,000 to 300,000 NEAs out there between 100 and 1000 meters in size. Any one of those might conceivably have our name on it. Indeed, such a rock is thought to hit the Earth once every two to four thousand years, with a destructive force on the order of a 80 megaton nuclear bomb.
But there is currently no official program or funding for a search to catalog the asteroids in this class. And if one were to be discovered next week, donâ€™t take any comfort from the scenes of steely-eyed NASA missile men saving the day in movies such as Deep Impact and Armageddon: NASA currently has no program or mandate to develop an asteroid deflection capability.
So what, if anything, should we do? To come back to the automobile analogy, the time has come to invest in a little insurance. For the first time in the history of our planet, the technical capability exists to detect and deflect an incoming impactor, thereby averting a natural disaster of colossal proportions. The prudent course of action is to spend a modest amount of money now, to be better prepared for this eventuality in the future.
Thatâ€™s where the B612 Foundation comes in. The B612 Foundation is a non-profit organisation comprised of scientists and astronauts concerned about the current lack of action to even lay the engineering groundwork to protect the Earth from impacting near Earth asteroids. Their goal is to get a demonstration mission flown by 2015 that will measurably alter the orbital parameters of a target asteroid in a controlled manner. For roughly the cost of a NASA Discovery-class mission, a prototype of their gravity tractor concept could prove out the capability to protect our planet long-term from the shooting gallery that is the inner solar system.
The gravity tractor in operation (Dan Durda/B612 Foundation)
I spoke to Rusty Schweickart about B612 and their efforts to promote the purchase of a little prudent â€˜collision insuranceâ€™:
OotC: Asteroid impacts on the surface of the Earth are a form of natural disaster distinct from others, in that we now have the technology (if not yet a demonstrated capability) to detect and prevent collisions before they occur. Why isnâ€™t more being done to take advantage of that?
Schweickart: First, the general public isnâ€™t yet aware enough of the threat itself to have any sense that prevention is of importance. Consequently the pressure on Congress to take action on this issue is low to non-existent.
B612 Foundation is continually wrestling with the question, given its extremely limited resources, of where to apply its efforts, lobbying Congress for action, educating the general public, or focusing on our primary goal of getting a demonstration of deflection capability off the ground.
OotC: The B612 Foundation grew out of a one day workshop studying asteroid deflection techniques in 2001. What led you to that workshop, and subsequent involvement with B612?
Schweickart: At the Association of Space Explorerâ€™s (ASE, www.space-explorers.org) annual Congress in Madrid in 2000, astronaut Franklin Chang-Diaz gave an update on the development of his VASIMR (plasma rocket) prototype. In passing Franklin mentioned that it could, among many other things, be used for asteroid deflection. Ed Lu and I spoke briefly afterward with Franklin about our shared interest in that application.
Subsequently Ed gave a lecture at Princeton where he and Piet Hut (Institute for Advanced Study) found common interest in the subject and agreed to call a meeting of other interested parties to discuss it. Ed called the meeting at NASA/JSC in October, 2001, invited me to attend and out of that we formed the B612 Foundation.
OotC: The B612 Foundationâ€™s stated goal is to significantly alter the orbit of an asteroid in a controlled manner by 2015. How do you envision achieving that?
Schweickart: In any way possible, but with recognition that timing is important. Clearly the gravity tractor concept, with no new technology needed and no detailed knowledge needed re asteroid characteristics, can be accomplished in relatively short order, provided the money and motivation (or authorization, in the case of NASA) is available.
OotC: What level of financial resource will that require? What funding sources or strategies are you pursuing?
Schweickart: The specific answer to this will require some detailed preliminary mission analysis. This mission, however, is far simpler than most Discovery class missions since it need carry virtually no scientific payloads, and Discovery missions fall in the $300M realm.
At the moment weâ€™re looking at what options for getting this mission underway make most sense.
OotC: While reading your website, I found these two simulations of what would happen if asteroid 2004MN4 (Apophis) were to strike in 2036 off the coast of California, or in the Gulf of Mexico. The risk of this actually happening is currently quantified as less than 1 in 5500, nonetheless these video simulations make sobering viewing. What sort of responses do you get when you talk to people about the risks from asteroids, and the B612 Foundationâ€™s goals?
Schweickart: They are astounded by the power of asteroid impacts and incredulous that nothing is being done. ANDâ€¦ very few of the general public have been exposed to the issues so graphically illustrated in Steve Wardâ€™s simulations. As you know everyone has a difficult time in dealing with very low probability events which have extremely high consequences. According to the economic loss model developed by Drs. Steve Ward and Steve Chesley the cost of the Pacific Ocean impact you refer to (modelled on an Apophis impact) is about $400 billion for infrastructure losses alone (i.e. destruction of â€œstuffâ€). I have no idea of what the total cost might be were one to count the loss of life and the general impact on the global economy.
One way for the ordinary person to grasp the situation is to think about car insurance as an analog. According to government statistics the probability of the average American driver having a reportable accident on any given day is about 1 in 10,000. If you assume that the average car costs $30,000 then multiplying the two together gives the amount one would rationally spend to insure against that loss, i.e., about $3/day.
In the case of Apophis the cost (infrastructure loss) is $400B and the current probability of impact (occurrence) is 1 in 5500 yielding a rational insurance expenditure of $7.3 M to mitigate against that potential loss. In fact weâ€™re spending essentially $0.00.
An interesting additional note is that in the case of auto insurance that expenditure does nothing whatever to prevent an accident from occurring.. it just makes the replacement car (or repair) easier to take. In the asteroid case the expenditure can actually prevent the occurrence of the event itself. (for the mathematicians out there, the probability of occurrence would need to get up to perhaps 1 in 50 before expenditure on an actual deflection were taken on.)
OotC: B612 has had a dialog with NASA regarding a mission to place a transponder on Apophis (2004MN4) to more precisely determine its orbit. Also, in a recent speech to the American Geophysical Union, NASA administrator Michael Griffin mentioned the Foundation, saying â€œAnd I’m also very intrigued by Ed Lu and Rusty Schweickartâ€™s ideas about nudging large near-Earth asteroids before they can pose a threat to humanity. We will most certainly continue our work to discover large asteroids close to the Earth.â€ It sounds like the Foundationâ€™s plans are well received at NASA: Can you describe your relationship with them, and any possibilities for working together?
Schweickart: Our relationship with NASA is just fine. The problem is not our relationship but rather the fact that NASA has no assigned responsibility or budget for protection of the Earth from asteroid impacts. Nor does anyone else in government, US or elsewhere in the world. NASAâ€™s circumstance is currently one where any money they do spend on this (even without authorization) would have to come out of something else (exploration or science) that they are doing. A zero-sum game, in other words. NASAâ€™s role would have to be expanded to include a small, but real public safety component.
OotC: Do you see any synergies between B612â€™s goals and NASAâ€™s plans to return to the Moon?
Schweickart: Not much. On the other hand going on to Mars might well incorporate an intermediate step of going on to certain near-Earth asteroids, for resource exploitation purposes, and others. (see Tom Jonesâ€™ Stepping stones to mars: The asteroid option, Aerospace America, June 2005)
OotC: Where are you at in terms of mission planning? Is the gravity tractor now your preferred mission approach?
Schweickart: Yes, the gravity tractor can be built and tested now, and by coincidence should we actually need an Apophis deflection (unlikely but possible) the gravity tractor is capable of doing the deflection job.
OotC: Has the data returned by previous asteroid missions such as NEAR, Deep Impact and even Hayabusa been a factor in the design changes from the original direct-contact plasma rocket concept?
Schweickart: Any information from or about asteroids is of use in designing any kind of deflection capability. Our earlier â€œasteroid tugboatâ€ concept needs both new technology and more data than is currently available about the nature of asteroid surfaces. Near and Hayabusa data can definitely contribute to design, but so far the data needed to design a method to attach to an asteroid after docking is not available.
OotC: How closely is the B612 Foundation associated with the groups searching for NEAs â€“ and is there currently an organised program to catalog the approximately 200,000 NEAs ranging in size between 50 and 1000 meters?
Schweickart: Weâ€™re in regular contact with both the JPL (Sentry) people and the University of Pisa (NEODyS) peopleâ€¦ itâ€™s a relatively small community. There have been many recommendations made (but none heeded) to modify the goal of the Spaceguard Survey down to 100-140 meter diameter asteroids. Congressman Dana Rohrabacher (R-CA) has sponsored legislation to allocate $20M for the next several years to improve the discovery capability, but no revision of the Spaceguard goal has yet been proposed or passed into law.
OotC: The risk of an asteroid collision is statistically low on any given day, but quite real over time – and the consequences if one were to occur are extreme. Given that, I would imagine people will want to see the goals of the B612 Foundation advanced with prudent speed. What can interested members of the public do to help?
Schweickart: The most important thing is to learn about the environmental (cosmic) circumstance in which the Earth is embedded. Thereâ€™s lots of information on the web, most especially on JPLâ€™s site at http://neo.jpl.nasa.gov. Beyond that the only option is to contributeâ€¦ most easily in terms of letters to Congresspersons. There are also, of course, financial contributions to B612 Foundation to support our efforts. Weâ€™ve got Paypal and credit card buttons on the Contact Us page of our website, and we welcome whatever folks can contribute.