Planetary Defense - Warning of Daytime Impacts and Asteroid Billiards

1. 3rd predicted meteor & 1st one photographed South Africa Planetary Defense - Warning of Daytime Impacts and Asteroid Billiards David W. Dunham, KinetX & Natan Eismont, Space Research Inst., Russian Acad. of Science Future In-Space Operations Telecon July 18, 2018 SODA 1

2. Overview • This considers two aspects of Planetary Defense: • 1. Find them before they find us, even in daylight; the System of Observation of Daytime Asteroids (SODA) • 2. Deflecting hazardous asteroids by directing small asteroids (or boulders from them) into the hazardous object using one or more Earth gravity assists • Some of the basic ideas were developed at the Russian Space Research Institute (IKI) and the Moscow Institute of Electronics and Mathematics (MIEM) while I was there in 2012 and 2013 with a grant from the Russian Ministry of Education and Science • Conclusions 2

3. Sun-Earth L1 Space Telescope as a Tool to Provide Warning of Hazardous Asteroids- now System of Observation of Daytime Asteroids (SODA) – 1st Part David W. Dunham KinetX Aerospace Boris M. Shustov Institute of Astronomy, Russian Academy of Sciences (RAS) Natan Eismont & I.D. Kovalenko, Space Research Institute, RAS Harold Reitsema and Ed Lu, B612 Foundation Robert Arentz, Ball Aerospace Robert Farquhar, was KinetX Aerospace 3

4. Outline of First Part • Near-Earth Objects (NEA’s); collisional probabilities and consequences • History of NEA impact (meteor) damage • Finding them before they find us (also, title of a book by Don Yeomans) – ground surveys • Overview, NASA Planetary Defense Missions • System of Observation of Daytime Asteroids (SODA) • Conclusions 4

5. Odds of Asteroid Impacts on Earthand number of known NEA’s by A. Harris 5

6. More Than One Million Unknown Near Earth Asteroids (NEAs) 6

7. Relative Odds of Asteroid Impacts * US National Safety Council 2008 7

8. History (and Pre-history) of Earth Impacts 8

9. The Chicxulub Impact 10km NEA (or 6km comet) hit shore of Yucatan 65 million years ago. Over 70% of plant and animal species perished from the blast, worldwide wide fires (from impact debris re-entering the atmosphere), and the collapse of photosynthesis in the cold dark years that followed. The dinosaurs died, and now humans rule, because they had no space program, no planetary defense. 9

10. Meteor crater, Arizona Age: 50,000 years Crater diameter: 1.1 km 50 m diameter, nickel-iron NEA Finally proved to have an impact origin by Eugene Shoemaker in 1963 Hazard From Asteroid Impacts • Asteroids have impacted Earth throughout its history, but most evidence of them is erased by plate tectonics and weather • Asteroids as small as 40 meter diameter can cause regional devastation 10

11. 1908 impact in Tunguska, Siberia Trees spread in radial pattern, scorched for 50 km across Windows broken hundreds of km away (shock wave) No crater found Probably caused by a rocky asteroid (30 – 60 m diameter) Like NEA 2012 DA14 (diam. 50 m) near Earth, 15 Feb. 2013 11

12. 15 February 2013 – 2 NEA’s near Earth • The Chelybinsk asteroid approached from the Sun, so it was a “bolt out of the blue”, we had no warning. • The larger (50m) NEA was discovered a year ago and flew by Earth at a record (for a non-impacting asteroid) 27,700 km altitude 15 Feb. 2013   Most NEA’s are Amor objects like Chelyabinsk, with perihelion inside Earth’s orbit and aphelion in the Main Belt. The NEA’s velocity relative to Earth is mainly towards the Sun before perihelion and mainly away from it after, so a rather large fraction approach from a direction too close to the Sun to be observed from Earth’s surface, or from low-Earth orbit. 12

13. 15 February 2013 – Russia gets struck again (Chelyabinsk) • Above, a crater on the ice of Lake Chebarkul caused by a piece from a 20-meter Near Earth Asteroid • Airburst at ~20 km with about 500 kilotons of TNT equivalent energy - 13

14. Shattered windows in over 4000 buildings and injured 1,500 people, 2 of them seriously. About 1 billion rubles of damage to buildings Windows had to be fixed quickly with temperature  -15 No warning with approach from the Sun Same day as the predicted harmless 50m 2012 DA14 close approach 14

15. Another Large Meteor Struck Russia on 12 February 1947 At 4m, this object was not as large as the Tunguska or Chelyabinsk Meteoroids but it was made mostly of iron, so about 23 tons of its original 70 tons mass reached the ground, creating over 100 craters over a 2-km area of remote forest in the Sikhote-Alin Mountains northeast of Vladivostok. The largest crater was about 26m across. The shock wave was smaller due to the lower (5 km) breakup and no structures were close enough to be damaged, although the impact flash, like the Chelyabinsk event, was as bright as the Sun Painting by P. J. Medvedev used On 1957 USSR stamp 15

16. Deaths caused by NEA impacts? • Below are unconfirmed, unlike the 1954 strike that injured Ann Hodges in Alabama and the 2013 Chelyabinsk injuries. • 616 AD – Jan. 14 – China, 10 deaths, siege towers destroyed. • 1321-1368 – O-chia district, China – iron rain kills people • 1490 – 3 Feb. - Ch'ing-yang, Shansi, China - Stones fell like rain; more than 10,000 killed – but the official Ming Dynasty history does not mention any casualties, and strangely, none of the stones are known today (while several much older meteorites have been saved) • 1511 - 14 Sept. - Cremona, Lombardy, Italy - Monk killed • 1654 - Milano, Italy - Monk reported killed by meteorite. • 1825 - 16 Jan. - Oriang, India - Man reported killed • 1879 - 31 Jan. - Dun-le-Poelier, France - Farmer reported killed. • 1929 - 8 Dec. Zvezvan, Yugoslavia - Meteor hits bridal party, kills 1 • 2007 – 22 Feb. – Rajasthan, India – 3 killed 16

17. Some other meteor strikes in the last 100 years with blasts strong enough to shatter windows • 1914 - 9 Jan. - W. France - Meteor explosions break windows • 1919 – 26 Nov. – s. Michigan, n. Indiana – broken windows & property damage (but also thunderstorms that night) • 1922 - 24 April - Barnegat, New Jersey - shattered windows • 1930 - 13 Aug. – Rio Curaca, Brazil - created 1-km crater “Brazilian Tunguska” • 1932 – 08 Dec. - Arroyomolinos de León, Spain – broken windows, buildings damaged • 1935 - 11 Dec. – Rupuni, British Guyana – 32km area of jungle shattered • 1954 - 07 Jan. -Dieppe, France - smashed windows • 1984 - 5 Dec. -Cuneo, Italy - Strong explosion, windows broken • 2007 – 15 Sept. – Carancas, Peru – 15m crater, fumes with arsenic sickened 200 • 2009 - Oct. 8 – S. Sulawesi, Indonesia – 10m NEA exploded with force of about 50,000 tons of TNT; a child may have been killed as a result • 2010 - Feb. 11 – central Mexico – 30m crater formed, damaged road • Some other large aerial blasts over the ocean detected by US military satellites since the 1990’s. Compiled in 2013 17

18. Low-Altitude Airbursts • The relative threat from them is increasing • Our understanding of them is improving • Almost certain to be the next destructive NEO • ~100 m, ~100 Mt, has ~1/100 chance this century* • 100 Mt will dominate threat after current survey • Tech development similar to threat reduction time • Other reasons to deflect/fragment small asteroids • Mitigation should focus on small (~100m) NEOs *“100/100/100 event” By Mark Boslough, Sandia National Laboratory 18

19. Chelyabinsk About half are daytime events, most invisible from the ground during their approach. Data from US satellites that monitor the globe for rocket launches. 19

20. Finding them before they find us –Searches for NEA’s 20

21. Discoveries of NEA’s • 1801, Jan. 1: (1) Ceres, the first asteroid, discovered by Giuseppe Piazzi at Palermo Observatory, Sicily, a part of an international search for a “missing planet” between Mars and Jupiter expected from the Titius-Bode law. • Photographic surveys started many years later found many more asteroids. • 1898, Aug. 13: (433) Eros, the first NEA, was discovered by Gustav Witt at Berlin and AugusteCharlois at Nice, but its orbit doesn’t cross Earth’s. • 1932, April 24: (1862) Apollo, first Earth-crossing asteroid, found by Karl Reinmuth at Heidelberg Observatory • 1976: (2062) Aten, 1st with a < 1, found by Eleanor Helin • 2003, Feb. 11: (163693) Atira discovered by LINEAR in New Mexico, the first asteroid with an orbit entirely inside Earth’s 21

22. Surveys for NEA’s • Photographic surveys looking for asteroids at several observatories in the 20th century, including at Crimean Astrophysical Observatory, Indiana University’s observatories, Palomar Observatory (Schmidt camera), and elsewhere • 1973 – mid 1990’s: Palomar Planet-Crossing Asteroid Survey (PCAS) by Eleanor Helin and Gene Shoemaker • 1993 – 2008: Lowell Obseratory NEO Survey (LONEOS) • 1995 – early 2007: JPL’s Near-Earth Asteroid Tracking (NEAT) at Haleakala, Hawaii • 1996 – now: Lincoln Near-Earth Asteroid Research (LINEAR) at Magdalena Ridge Observatory, New Mexico • 1998 – now: Catalina Sky Survey, Arizona and Australia • 2008 – now: Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) - will use 4 1.8m telescopes • 2009 – 2011: Wide-field Infrared Survey Explorer (WISE) – Discovered many NEA’s as part of its NEOWISE program • 2013 Feb. 26: Launch of Near Earth Object Surveillance Satellite (NEOSSat) by Canada, 15cm telescope will search for Atira asteroids between 45 and 55 solar elongation • ?: Sentinel space telescope mission, see next slides • Start 2022: Large Synoptic Survey Telescope (LSST) – 8.4m telescope, wide-field CCD’s, under construction in northern Chile 22

23. Sentinel Mission Description • 50-cm (20-inch) Infrared Telescope in an orbit around the Sun at the distance of Venus • Nominal 6.5 year mission lifetime • Continuously scan the sky opposite the Sun • Sensitive to Near Earth Asteroids as small as 30-meter diameter • Determine their positions and orbits to map their future locations to look for possible threats • Will also enable a new era in characterization and exploration of the NEO population through discovery of NEAs that are easy to visit and return to Earth • NASA collaboration through Space Act Agreement • Mission cost about $450 million, but so far, it has not been funded 23

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26. So far, Sentinel hasn’t been funded, but the idea of asteroidal surveys from space has gained traction following the success of NEOWISE 26

27. 27 Lindley Johnson, NASA, at SBAG mtg., June 13, 2018

28. Amy Mainzer, NASA-JPL, at SBAG meeting., June 13, 2018 28

29. Amy Mainzer, NASA-JPL, at SBAG meeting., June 13, 2018 29

30. NEOCam is a survey mission, not a warning system; it looks to the sides from SE-L1 rather than in a cone centered at the Earth Amy Mainzer, NASA-JPL, at SBAG meeting., June 13, 2018 30

31. SEntineL1 for “Bolts out of the Blue” • Chelyabinsk showed that even asteroids as small as 15m can cause extensive damage • There are several million NEA’s larger than 15m • The surveys are finding less than 1% of these objects • They are too small to observe at large distances, so • They can only be seen when they approach or pass near the Earth • Since many have Earth-like orbits with periods near a year, it will be centuries before a large fraction of them could be found with current technology • In December 2012, the B612 Foundation suggested to NASA that a copy of the Sentinel spacecraft might be placed in a Sun-Earth L1 orbit, to warn of hazardous daytime NEA’s • Dunham had the same idea shortly after the Chelyabinsk meteor, then found out about B612, and worked with them. • These ideas were published by Dunham et al. in Solar System Research, Vol. 47, pp. 315-324, 2013. 31

32. Sun-Earth L1 (SE-L1) Libration Point Halo Orbit • The L1 libration point is 1.5 million km from the Earth to the Sun • The gravitational forces of the Sun and Earth, and the centrifugal force in the rotating coordinate system, balance at this point • With a certain combination of out-of-plane and in-plane amplitudes, the periods of motion in both directions can be made the same, allowing a “halo” orbit to be flown • This is needed to avoid communication interference from the Sun as seen from Earth • The halo orbit is unstable, but only small maneuvers 4 times a year can keep a spacecraft (like SOHO) on the path for many, many years 32

33. System of Observations of Daytime Asteroids (SODA) HCB = Hazardous Cosmic Body Earth from Shustov et al., Astronomy Reports, 2015, Vol. 59, pp. 983-996 33

34. SODA Spacecraft Schematic Speed of rotation: one rev. each 20 min. Number of frames per revolution: 120 (exposure 10 s) Frame volume: 4000 × 3000 × 16 bits Field: 3perpendicular to scanning, 2.2along the frame. Detectable asteroid size:10m from Shustov et al., Astronomy Reports, 2015, Vol. 59, pp. 983-996 34

35. SODA Transfer Trajectory and Lissajous Orbit Two spacecraft are preferred, for better & faster OD of the asteroids. They can be launched with one Soyuz 2.1b and Fregat-SB upper stage that gives V1 = 3814 m/s from the parking orbit. Spacecraft 1 immediately applies V2 = 10 m/s that allows it to reach the L1 orbit while Spacecraft 2 follows the dotted line back to Earth. It applies V3 = -13 m/s to adjust the lunar swingby distance to 24,000 km that boosts the trajectory to the same L1 orbit, but 21 days behind Spacecraft 1. Earth Solar rotating ecliptic plane projection with fixed horizontal Earth-Sun line Kovalenko, Shustov, & Eismont, Traj. Design for SODA, Acta Astronautica, 2018, in press 35

36. SODA Lissajous Orbit, View towards the Sun, 10 years Period 181 days After 10 years, the spacecraft will cross the Solar exclusion zone (SEZ), but at different times, so one spacecraft will always be able to transmit observations quickly. For only a short period, the asteroid OD accuracy will be reduced while one spacecraft is in SEZ. Solar Exclusion Zone 5 36 Kovalenko, Shustov, & Eismont, Traj. Design for SODA, Acta Astronautica, 2018, in press

37. The SODA Spacecraft • Could observe asteroids down to 10 m in size approaching the Earth from a direction from the Sun • It could sweep out the annular region every day • Any asteroid approaching from the Sun must pass through the viewing region two to five days before it would strike the Earth • This is an area blind to ground observatories, and also to spacecraft orbiting in low-Earth orbit; they can find NEA’s approaching from other directions • It could give us often a day, but at least a few hours, of warning before an impact, rather than the 1-2 minutes from the flash to the shock wave arrival in Chelyabinsk 37

38. Conclusions • Before we can protect Earth from the NEA threat, we need to know about them. • A telescope in a Sun-Earth L1 halo orbit can give us one or more days of warning for NEA’s coming from the Sun • No more “Bolts out of the Blue”; we’ll know about them, and can learn more about NEA’s • “When the fate of the planet is at stake, we’re going to have to do a better job. Any one lifetime might be a fleeting thing, but asteroids are forever. Our defenses (against them) must be, too.” – J. Kluger, Time Magazine, 2013 February 25 38

39. 2nd Part - USING SMALL ASTEROIDS TO DEFLECT LARGER DANGEROUS ASTEROIDS D. Dunham(2,3), N. Eismont(1,2), M. Boyarsky(1,2), A. Ledkov(1,2), R. Nazirov(1,2), K. Fedyaev(1,2) (1)Space Research Institute of Russian Academy of Science, (2) Moscow Institute of Electronics and Mathematics of National Research University “Higher School of Economics” (3)KinetX, • Future In-Space Operations Telecon - July 18, 2018 39

40. Overview • Goals • Feasibility of moving small asteroids – Asteroid Redirect Mission • Finding Small Asteroids from Sun-Earth L1 Orbit [Already discussed in the 1st Part] • Earth Gravity Assist to change asteroid orbit • Possibilities to Deflect Apophis (the same ideas can be used for other potentially hazardous asteroids) • Pre-positioning small asteroids in 1-year return orbits • Conclusions and Acknowledgment 40

41. Deflecting Hazardous NEA’s • If a NEA is found on a collision course with the Earth, there are different ways of deflecting them • It is best to have at least a few decades of warning • Then a mission can be executed to study the object in detail and • Only a small maneuver is needed to avoid the Earth 41

42. Deflection Methods • Kinetic impact (striking the NEA with a large spacecraft) • Gravity tractor (spacecraft kept above one side of the NEA) • Painting, or wrapping the NEA with a reflective (or dark) sheet, to change its tiny Yarkovsky acceleration • Installing mass drivers on the asteroid, to send the NEA’s material in one direction • A last option, if there isn’t enough time for the slow methods above, would be to use hydrogen bombs on powerful rockets. If nations can maintain a nuclear strike capability against each other, then one or two rockets might be maintained, only as a last resort, against very damaging NEAs that might be found from L1 • Another way between the slow and fast option, is to change the orbit of a small (5 – 10m) asteroid approaching the Earth so that it swings by the Earth in a different direction so that it can hit the hazardous NEA; this method is about 200 times more efficient than the direct kinetic impact approach 42

43. Feasibility of moving small asteroids, or boulders from them, has been shown by the studies for NASA’s no-longer-funded Asteroid Redirect Mission Rather than moving the boul- der to capture into a Lunar orbit, we propose to move it instead to a B-plane point such that Earth’s gravity bends its orbit towards a hazardous asteroid. Images from NASA 43

44. The basic concept IV. flight along trajectory to the Earth III. applying to the asteroid-projectile the velocity pulse Apophis VI. Collision with dangerous asteroid I. Start of spacecraft from the Earth II. Landing and fixing the spacecraft on asteroid surface V. Gravity assist maneuver 44

45. The main idea consists of targeting a very small asteroid to impact a larger dangerous one. The minimum size of this small asteroid is determined by the ability to detect it and to determine its orbit. The small object may have a diameter of about 10 -15 meters. Asteroids are selected from the near-Earth class that have a fly-by distance from Earth of the order of hundreds of thousands of kilometers. According to current estimates, the number of near Earth asteroids with such sizes is high enough. So there is a possibility to find the required small asteroid. Further, the possibility is evaluated of changing the small asteroid’s orbit so that by application of a very limited delta-V impulse to the asteroid, the latter is transferred to a gravity assist maneuver (Earth swingby) that puts it on a collision course with a dangerous asteroid. It is obvious that in order to apply the required V pulse it is necessary to install on the small asteroid an appropriate propulsion system with required propellant mass. The main goal is to demonstrate that this concept is feasible. 45

46. Cylinder of possible vectors of relative velocities at arrival and resulted after fly-by cone of velocity vectors of departure Cone of velocity vectors of departure α Angle of rotation of relative velocity of asteroid-projectile at infinity 46

47. Geometry of gravity assist maneuver in coordinate system connected with Sun 47

48. Results of candidate asteroids chosen and orbits design *for departure delta-V optimization, Red corresponds total Delta-V optimization 48

49. ΔV = 10 m/s IV. flight along trajectory to the Earth III. applying to the asteroid-projectile the velocity pulse Apophis VI. Collision with dangerous asteroid Impact velocity = V = 2-14 km/s I. Start of spacecraft from the Earth 49 II. Landing and fixing the spacecraft on asteroid surface V. Gravity assist maneuver Rp=7000 - 35000 km ΔV braking for landing S/C on an asteroid= 0.5 km/s

50. Asteroid 2011 UK • Optimal transfer trajectory to 2011 UK asteroid with minimum total delta-V (C3 47.18 km2/s2, rendezvous V 543 m/s) b) Transfer trajectory to 2011 UK asteroid with minimum departure delta-V (C3 1.49 km2/s2, rendezvous V 5.57 km/s) Earth Venus Venus Earth Sun Sun 2011 UK 2011 UK Mercury Mercury Mars Mars 50