AFRL-AFOSR-JP-TR-2016-0008 Charging of space debris and their dynamical consequences

The charging of space debris due to the ambient plasma environment in the low earth orbit (LEO) and geostationary earth orbit (GEO) regions of the ionosphere has been investigated using both analytic and particle-in-cell (PIC) modeling. The analytic estimates have been obtained using improved Orbit Motion Limited (OML) modeling while the simulation studies have been carried out using the open source simulation code SPIS. In the GEO region account has been taken of charging arising from photoemission effects as well as due to the impact of energetic charged particle beams associated with solar flares. The PIC approach has also been used to study differential charging of debris objects that are composed of patches of conducting and insulated regions. For debris sizes larger than a few microns the orbital perturbations arising from the interaction of the debris charge with the ambient magnetic field and ionospheric electric fields are found to be insignificant in comparison to those arising from gravitational and solar radiation pressure effects and hence may have a negligible influence on orbital calculations. However the debris charge can give rise to nonlinear electrostatic wave excitations in the ambient plasma in the form of precursor solitons that move ahead of the debris. A model calculation delineating the conditions and nature of such excitations has been carried out. A controlled laboratory experiment to test this theoretical concept has also been done and has shown the first ever excitation of precursor solitons in a plasma medium. Detection of such waves in the debris orbital regions using ground-based techniques can provide a novel method of detecting centimeter-sized objects that are otherwise difficult to track using optical methods. The discovery of these precursor excitations also opens up potential new areas of fundamental and applied research in the field of plasmas and space physics. DISTRIBUTION A: Distribution approved for public release. Work done report The main objectives of this study have been to estimate the amount of charge that debris objects of various sizes and composition can acquire in the LEO and GEO environment of the earth, to assess the potential impact of this charging on their orbital dynamics and to explore possible ways of exploiting their charged state to aid their detection and tracking. In pursuit of these objectives we have (i) made analytic and PIC simulation based estimates of debris objects in various size ranges and for different materials and shapes, (ii) assessed their impact on orbital dynamics by comparing the electromagnetic forces they experience with the other forces acting on them and (iii) proposed a novel method of tracking debris objects by detecting solitonic precursor wave excitations that can occur due to the large amount of charge on them. (iv) confirmed the conceptual basis of the precursor excitation in a controlled laboratory experiment. For details about (i) and (ii) please refer to the technical report entitled: Abhijit Sen, Sanat Tiwari, Sanjay Mishra, and Predhiman Kaw, “Charging of Space Debris in the LEO and GEO regions” (attached as Annexure I). For details on (iii) please refer to the publications: Abhijit Sen, Sanat Tiwari, Sanjay Mishra, and Predhiman Kaw, “Nonlinear wave excitations by orbiting charged space debris objects”, Advances in Space Research 56, 429–435 (2015). (attached as Annexure II) Sanat Kumar Tiwari, and Abhijit Sen, “Wakes and precursor soliton excitations by a moving charged object in a plasma”, accepted for publication in Physics of Plasmas. (attached as Annexure III) For details on (iv) please refer to the publications: Surabhi Jaiswal, P. Bandyopadhyay, and A. Sen, “Experimental observation of precursor solitons in a flowing complex plasma”, submitted to Physical Review Letters. (attached as Annexure IV) S. Jaiswal , P. Bandyopadhyay , and A. Sen, “Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow”, Review of Scientific Instruments 86 , 113503 (2015) (attached as Annexure V) DISTRIBUTION A: Distribution approved for public release. List of Publications and Significant Collaborations that resulted from the AOARD supported project a) Papers published in peer-reviewed journals (i) Abhijit Sen, Sanat Tiwari, Sanjay Mishra, and Predhiman Kaw, “Nonlinear wave excitations by orbiting charged space debris objects”, Advances in Space Research 56, 429–435 (2015). (ii) S. Jaiswal , P. Bandyopadhyay , and A. Sen, “Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow”, Review of Scientific Instruments 86 , 113503 (2015) (iii) Sanat Kumar Tiwari, and Abhijit Sen, “Wakes and precursor soliton excitations by a moving charged object in a plasma”, accepted for publication in Physics of Plasmas b) Papers published in peer-reviewed conference proceedings, Nil c) Papers published in non-peer-reviewed journals and conference proceedings, Nil d) Conference presentations without papers, (i) Abhijit Sen, Sanat K Tiwari, Sanjay K Mishra, Predhiman Kaw and A Surjalal Sharma, Charging of space debris in the LEO and GEO regions, 40th COSPAR Scientific Assembly, 2-10 August 2014, Moscow, Russia. (ii) A. Sen, S. K. Tiwari, S. K. Mishra, and P. Kaw, Nonlinear Wave Excitations By Orbiting Charged Space Debris Objects, 17 International Congress On Plasma Physics 2014, September 15-19, 2014, Lisbon, Portugal. (iii) Abhijit Sen, Sanat Tiwari, Sanjay Mishra and Predhiman Kaw, Indirect Detection of Charged Space Debris via Nonlinear Wave Excitations, 1st URSI Atlantic Radio Science Conference (URSI AT‐RASC), 18 ‐ 25 May 2015, Gran Canaria, Spain. e) Manuscripts submitted but not yet published, (i) Surabhi Jaiswal, P. Bandyopadhyay, and A. Sen, Experimental observation of precursor solitons in a flowing complex plasma, submitted to Physical Review Letters. DISTRIBUTION A: Distribution approved for public release. f) List any interactions with industry or with Air Force Research Laboratory scientists or significant collaborations that resulted from this work. Scientific exchanges via email with the following scientists: (i) Dr. Moriba Jah, Air Force Research Laboratory, Kihei, Maui (ii) Dr. A.S. Sharma, Space and Plasma Physics Group, Department of Astronomy, University of Maryland, College Park, MD, 20742-­‐2421 (iii) Dr. Carolin Frueh, University of New Mexico, USA/Air Force Research Laboratory (presently at Purdue University) (iv) Dr. Ryan M. Weisman, Research Aerospace Engineer Guidance, Navigation, and Controls Program Air Force Research Laboratory (AFRL/RVSV) 3550 Aberdeen Ave. SE Kirtland AFB, NM 87117 (v) Dr. Dale Ferguson, Air Force Research Laboratory, U.S.A. (vi) Dr. Stephen R. Gildea, Aerospace Engineer, In-­‐Space Propulsion Branch (RQRS) Air Force Research Laboratory Edwards Air Force Base, CA DISTRIBUTION A: Distribution approved for public release. Charging of Space Debris in the LEO and GEO regions Abhijit Sen, Sanat Kumar Tiwari, Sanjay K Mishra, Predhiman Kaw∗ Institute for Plasma Research, Bhat, Gandhinagar 382428, India Abstract We investigate the charging of space debris due to the ambient plasma environment in the low earth orbit (LEO) and geostationary earth orbit (GEO) regions of the ionosphere using both analytic and particle-in-cell (PIC) modeling. The analytic estimates are obtained using improved Orbit Motion Limited (OML) modeling while the simulation studies are carried out using the open source simulation code SPIS. In the GEO region account is taken of charging arising from photoemission effects as well as due to the impact of energetic charged particle beams associated with solar flares. Using the PIC approach we also study differential charging of debris objects that are composed of patches of conducting and insulated regions. The dynamical consequences of debris charging on their orbital trajectories and rotational characteristics are found to be insignificant for debris sizes larger than microns due to the predominance of gravitational and other forces acting on them. The charge can however provide a direct means of detecting small sized debris objects by in-situ measurements of the resultant currents.We investigate the charging of space debris due to the ambient plasma environment in the low earth orbit (LEO) and geostationary earth orbit (GEO) regions of the ionosphere using both analytic and particle-in-cell (PIC) modeling. The analytic estimates are obtained using improved Orbit Motion Limited (OML) modeling while the simulation studies are carried out using the open source simulation code SPIS. In the GEO region account is taken of charging arising from photoemission effects as well as due to the impact of energetic charged particle beams associated with solar flares. Using the PIC approach we also study differential charging of debris objects that are composed of patches of conducting and insulated regions. The dynamical consequences of debris charging on their orbital trajectories and rotational characteristics are found to be insignificant for debris sizes larger than microns due to the predominance of gravitational and other forces acting on them. The charge can however provide a direct means of detecting small sized debris objects by in-situ measurements of the resultant currents. ∗ [email protected] 1 DISTRIBUTION A: Distribution approved for public release.