Op-ed | A space-based survey, not luck, must be our plan against hazardous asteroids
This op-ed originally appeared in the Sept. 24, 2018 issue of SpaceNews magazine.
Luck is not a plan. Yet up to now Congressional appropriators and senior NASA officials are mostly relying on luck to keep us safe from catastrophic fatalities resulting from the surprise impact of an unseen asteroid. So far, luck and the odds are on our side as evidenced by both the 1908 Siberian Tunguska impact and the 2013 Chelyabinsk airburst occurring in relatively remote areas of our planet. Alas, nonpartisan studies commissioned by the National Research Council have determined, as a scientific fact that one day our luck will run out. It could be next year or it could be next century; that is the nature of a random threat. Only by discovering and tracking the hundreds of thousands of asteroids crisscrossing Earth’s orbit can we know for sure. The opportunity to do just that is now within our grasp. We call on Congress and NASA to come together and commit to securing our future against hazardous asteroids.
Congressional authorizations have fully embraced the imperative to “know thy enemy.” The George E. Brown Survey Act of 2005 (H.R. 1022; 109th) mandates NASA to achieve by the year 2020 specific levels of search completeness for discovering, cataloging, and characterizing asteroids whose impacts could devastate major cities or even larger congressional districts. Rather than launching a full-scale search as mandated by the Survey Act, more than a decade-long game of “cosmic chicken” has ensued with NASA refusing to take sufficient action until Congress enacts a sufficient appropriation. In turn, Congress has been generous in overall NASA appropriations, but top NASA managers have not prioritized the funds needed to meet the specific goals of H.R. 1022.
As Earth waits inevitably in the crosshairs, it is time for the game of cosmic chicken to stop. Both sides must come together and commit to the mandate of H.R. 1022. Right now the timing of the FY19 budget presents a win-win-win scenario to do just that, created by a convergence of three factors: (1) A proposed asteroid survey spacecraft specifically designed to meet the mandate is ready-to-build. The competitively solicited Near-Earth Object Camera (NEOCam) mission is primed to advance after a decade of successful reviews and cost reduction studies. (2) A newly announced NASA mission launching in 2024 (the Interstellar Mapping and Acceleration Probe, or IMAP) has extra payload capacity heading to NEOCam’s operating outpost, the L1 Lagrange point inside of Earth’s orbit. (L1 is a stable orbit location where the opposite gravitational tugs of the Sun and Earth cancel out.) NEOCam and IMAP could make perfect co-manifest partners, yielding significant cost savings to the taxpayer approaching $100 million. (3) NASA’s newly proposed Planetary Defense budget line is within sight of the level needed to finally move NEOCam out of its successful Phase A validation into Phase B toward construction. Making that move requires decisions now for an on-time departure.
The funding gap determining our asteroid future currently stands at only $40 million. Raising NASA’s Planetary Defense budget line to $200 million in FY19, up from the current House number of $160 million, creates headroom for the $60 million immediately needed to propel NEOCam forward to its cost-saving 2024 launch date. The House of Representatives has taken the lead with $20 million allocated in their current budget proposal, but that amount won’t get NEOCam to the pad on time. Senate support is, of course, needed as well. Public opinion overwhelmingly favors making the investment, with more than 60 percent of respondents in a March 2018 Pew Research Center poll (2,500 Americans) saying NASA’s top priority should be to “monitor asteroids/objects that could hit Earth.” Out of all other NASA priorities listed as choices, including human space flight, only climate monitoring ranked higher. A Bloomberg poll in July (2,200 U.S. adults) delivers an identical one-two priority punch to NASA in its rankings. Even the White House agrees. The National Science and Technology Council’s June 2018 report National NearEarth Object Preparedness Strategy and Action Plan specifically directs NASA to take the lead in achieving the plan’s top goal: “Enhance NEO detection, tracking and characterization capabilities.”
SO, WHAT ARE WE WAITING FOR?
To be fair, the NASA Planetary Defense budget is supporting an array of ground-based telescope surveys scraping along toward 40 percent completeness as well as a demonstration project testing how we might deflect an asteroid. Search help may be coming from the broader astronomical community thanks to the Large Synoptic Survey Telescope (LSST), which with some trade-off to its astrophysical objectives, could tune its observing cadence in support of asteroid detection, eventually reaching 75 percent. Yet, reaching the 90 percent completeness level (for objects 140 meters across and larger) mandated by law definitively requires a space-based asset such as NEOCam — a key finding delivered by a 2017 Science Definition Team comprised by asteroid experts spanning the government and private sector. With the Sun at its back and cameras looking outward toward Earth’s vicinity, NEOCam’s infrared sensors achieve 24/7 scanning that is free from day/night cycles (not to mention cloudy weather), pushing to 90 percent completeness much faster and with much greater accuracy than any ground-based system. For objects that will be discovered heading toward a close brush with Earth (even now we detect sizable objects passing closer than the moon every week), precise knowledge delivered by NEOCam for both trajectory and physical size makes all the difference in the world for friend-or-foe analysis and if necessary, disaster mitigation planning. But we have to find them first, and the sooner the better. Putting time on our side in identifying and verifying any actual future threat is the greatest asteroid defense that money can buy.
So, what are we waiting for? It is time, right now in the FY19 budget, to take luck out of the equation and replace it with definitive knowledge of what’s out there. Congress needs to fully support NEOCam’s cost-effective advance to the launch pad. NASA leadership should take advantage of Congressional support and strong public opinion and fully commit to the NEOCam mission.
Richard P. Binzel is a professor of planetary science at the Massachusetts Institute of Technology and the inventor of the Torino Scale for characterizing the hazard of newly discovered asteroids. Donald K. Yeomans is a retired senior research scientist from the Jet Propulsion Laboratory and former manager of NASA’s Near Earth Object Program Office. Timothy D. Swindle is the director of the University of Arizona’s Lunar and Planetary Laboratory and chair of NASA’s Small Bodies Assessment Group which has issued repeated findings in support of space-based surveys for planetary defense. Each author declares no affiliation with NEOCam.