AD-A333 446. Thesis (. in Astronautical Engineering and . in Applied Physics)-Naval Postgraduate School, June 1997. Includes bibliographical references (p. 53).
AD-A333 446. An analysis of the effects of small impulses on Earth impacting asteroids is presented. The analysis is performed using a numerical routine for an exact, two body, analytic solution. The solution is based on two dimensional, two body, Earth intersecting elliptical orbits
Elder, Jeffrey T. Publication date. Rendezvous trajectories,asteroids,elliptical orbit trajectories.
Elder, Jeffrey T. 1997-01-01T00:00:00Z.
Optimization problems are formulated to calculate optimal impulses for deflecting Earth-Crossing Objects using .
Optimization problems are formulated to calculate optimal impulses for deflecting Earth-Crossing Objects using a Nonlinear Programming. This formulation allows us to analyze the velocity changes in normal direction to the celestial body's orbital plane, which is neglected in many previous studies. The proposed strategy is expected to give useful insights into preparing more advanced future deflection missions.
An optimal deflection method for Earth-Crossing Objects (ECOs) is formulated using a power limited .
An optimal deflection method for Earth-Crossing Objects (ECOs) is formulated using a power limited spacecraft. To avoid the Earth impact, ECO's momentum is changed continuously using a power limited laser ablation system carried by the conceptual future spacecraft. For the low-thrust asteroid deflection case, in which the orbital elements vary by an extremely small amount, such optimum condition corresponds to having the thrust vector virtually tangent to the orbit at all times (Song et al.
Since ideal optimal deflection conditions cannot always be achieved, a characterization of optimal mission. opportunities is performed for a restricted group of selected asteroids over a very wide range of possible launch. The patched conic method is used to formulate the constrained optimization problem. Geocentric constraints are mapped to heliocentric variables by the use of the impact parameter.
Earth-Crossing Asteroids. Can we do anything about an asteroid that is destined to hit the Earth? The answer is, yes, providing that it is small enough and that we have enough time to send a spacecraft to deflect it. As we will see, the longer the warning time we have, the larger the asteroid we will be able manage. Many of the aspects of asteroid impact mitigation were summarized in the Spaceguard Report. More recently, NASA has also completed a study and is being used by congress to decide what steps the US and other nations can and should take.
1994) The population of Earth-crossing asteroids, Hazards Due to Comets & Asteroids, T. Gehrels (e., Univ Cite this chapter as: Conway . 1999) Optimal Low-Thrust Interception and Deflection of Earth-Crossing Asteroids., Univ. of Arizona Press, Tucson, pp. 285–312. 2. MICA, an Interactive Astronomical Almanac, (1989) . Naval Observatory, Washington D. oogle Scholar. Cite this chapter as: Conway . eds) The Dynamics of Small Bodies in the Solar System. NATO ASI Series (Series C: Mathematical and Physical Sciences), vol 522.
for intercepting, impacting, and deflecting near-earth asteroids .
Park, and S. D. V. Porter, Gravitational effects of earth in optimizing ΔV for deflecting earth-crossing asteroids, Journal of Spacecraft and Rockets, vol. 38, no. 5, pp. 759–764, 2001. B. Dachwald and B. Wie, Solar sail trajectory optimization for intercepting, impacting, and deflecting near-earth asteroids, in Proceedings of the AIAA Guidance, Navigation, and Control Conference and Exhibit, pp. 3331–3348, San Francisco, Calif, USA, August 2005. G. Zhang, D. Zhou, D. Mortari, and T. A. Henderson, Analytical study of tangent orbit and conditions for its solution existence, Journal of Guidance, Control, and Dynamics, vol. 35, no. 1, pp. 186–194, 2012.
Asteroid impact avoidance comprises a number of methods by which near-Earth objects (NEO) could be diverted, preventing destructive impact events. A sufficiently large impact by an asteroid or other NEOs would cause, depending on its impact location, massive tsunamis, multiple firestorms and an impact winter caused by the sunlight-blocking effect of placing large quantities of pulverized rock dust, and other debris, into the stratosphere.
This paper presents an analysis of optimal impact strategies to deflect potentially dangerous asteroids. To compute the increase in the minimum orbit intersection distance of the asteroid due to an impact with a spacecraft, simple analytical formulas are derived from proximal motion equations. The proposed analytical formulation allows for an analysis of the optimal direction of the deviating impulse transferred to the asteroid. This ideal optimal direction cannot be achieved for every asteroi. ONTINUE READING.