Kaushik Iyer Print


  88936

  Kaushik.Iyer@jhuapl.edu

: SES

:   Materials Physicist

:  Earth, Planetary

  Europa Mission, New Horizons, Solar Probe Plus

 
1997, Ph.D. in Materials Science & Engineering, Vanderbilt University

Iyer's expertise is in the area of Space Environment Hypervelocity Impact Hazard Mitigation. He has also collaborated with planetary scientists to tailor material models for simulating planetary features resulting from HVI.

Interplanetary dust particle (IDP) and space debris hazard mitigation is a recurring concern to critical spacecraft mission ops and science payloads.  NASA’s Mars Reconnaissance Orbiter, Cassini to Saturn and its moons, Juno to Jupiter and New Horizons to Pluto are some recent and ongoing missions that have had to evaluate the hazards of micron-to-millimeter scale porous cometary and asteroidal particles consisting of dense rocky and iron aggregates traveling at tens to hundreds of kilometers per second relative to exposed spacecraft components.  At such speeds, even dust sized particles have the potential to destroy or disrupt cooling systems, power systems, electrical systems and instruments.  Naturally, these risks are more severe for longer missions and dustier orbits.  Earth-orbiting satellites and the ISS face similar hazards from manmade orbital debris (OD) also.  The science of evaluating the risks to missions associated with these hazards, specific system failure and damage modes, and providing mitigating design specifications to vulnerable systems involves a unique multi-disciplinary capability that spans expertise in spacecraft systems engineering, mission operations, planetary science, hypervelocity impact (HVI) shock physics, materials science and mechanical engineering.

For evaluating spacecraft/satellite damage and failure modes, the space systems HVI hazard mitigation community currently uses extrapolation of HVI data generated at ground testing speeds (2-10 km/s) out to higher, realistic impact speeds such as 30 km/s; even though the material response mechanism changes from mechanical failure to thermal phase change and dissociations after about 9 km/s.  As concern over the possibility of unacceptable damage to spacecraft/satellite components from dust impacts has grown, engineers have come to rely on multi-layer insulation (MLI) blankets not only for thermal control but also for protection against dust.  Application of the current extrapolation methodology developed for metal monolithic shields has proliferated to blankets and other non-monolithic structures also.  Extrapolation is generally hoped to provide high levels of protection with margin (conservatism), but this is not verified in any way despite changes in structure and material response at higher impact speeds. 

Dust hazard mitigation work at the Space Exploration Sector (SES) of The Johns Hopkins University Applied Physics Laboratory (JHU/APL) over the past 6 years has led to a systematic reduction in the need to rely on extrapolations for materials/systems damage assessments.  This work, for the Solar Probe Plus (SPP) and other missions, was necessitated by unprecedented exposure to dust impacts at speeds as high as 300 km/s and extensive reliance on blankets for protection.  The APL methodology integrates ground-based HVI testing and failure analysis for validation, and rigorously tested and verified shock physics-based hydrocode computations for shielding design.  It is not only data- and physics-based but also quantifies safety margins.  The physics-based methodology shows that the current extrapolation methodology for predicting the protective capability of blankets is in fact non-conservative up to about 45 km/s.  The methodology is also amenable to treating advanced non-metallics and complex materials considered for shielding such as MLI and honeycomb structures, as well as systems such as solar arrays, which are beyond the capability of the existing approach.

 
AGU Index Category AGU Index Sub-Category
INTERPLANETARY PHYSICS Interplanetary dust
ELECTROMAGNETICS General or miscellaneous
:
2010 - Present
Principal Professional Staff, Section Supervisor, Project Manager, Johns Hopkins University Applied Physics Laboratory
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2015: Outstanding Development Paper in an Externally Referred Publication: Interplanetary Dust Particle Shielding Capability of Spacecraft Multi-Layer Insulation
2013: R. W. Hart Prize for Best IR&D Research Project
:
The following publication information was downloaded from http://www.researcherId.com/rid/H-1411-2016. Click on the publication title to view details.
Dynamic yielding and fracture of grade 4 titanium in plate impact experiments
:   Whelchel, R. L.; Mehoke, D. S.; Iyer, K. A.; Sanders, T. H., Jr.; Thadhani, N. N.
:MAR 21 2016
: Journal of Applied Physics
  119
  --
  --
: WOS:000373383300047
: None
Hypervelocity impact of a steel microsphere on fused silica sheets
:   Chadegani, Alireza; Iyer, Kaushik A.; Mehoke, Douglas S.; Batra, Romesh C.
:JUN 2015
: International Journal of Impact Engineering
  80
  116
  132
: WOS:000353861400011
: None
Interplanetary Dust Particle Shielding Capability of Spacecraft Multilayer Insulation
:   Iyer, Kaushik A.; Mehoke, Douglas S.; Batra, Romesh C.
:MAR 2015
: Journal of Spacecraft and Rockets
  52
  584
  594
: WOS:000351621400026
: None
Large-scale troughs on Vesta: A signature of planetary tectonics
:   Buczkowski, D. L.; Wyrick, D. Y.; Iyer, K. A.; Kahn, E. G.; Scully, J. E. C.; Nathues, A.; Gaskell, R. W.; Roatsch, T.; Preusker, F.; Schenk, P. M.; Le Corre, L.; Reddy, V.; Yingst, R. A.; Mest, S.; Williams, D. A.; Garry, W. B.; Barnouin, O. S.; Jaumann, R.; Raymond, C. A.; Russell, C. T.
:SEP 29 2012
: Geophysical Research Letters
  39
  --
  --
: WOS:000309415700002
: None
A Review of the Solar Probe Plus Dust Protection Approach
:   Mehoke, Douglas S.; Swaminathan, P. K.; Carrasco, Cesar J.; Brown, Robert C.; Kerley, Gerald I.; Iyer, Kaushik A.; IEEE
:2012
: 2012 Ieee Aerospace Conference
  --
  --
  --
: WOS:000309105301002
: None
Relationships between multiaxial stress states and internal fracture patterns in sphere-impacted silicon carbide
:   Iyer, Kaushik A.
:JUL 2007
: International Journal of Fracture
  146
  1
  18
: WOS:000251682700001
: None
Analysis of the size effect in partial-slip contact fatigue
:   Iyer, K
:APR 2005
: Journal of Tribology-Transactions of the Asme
  127
  443
  446
: WOS:000228823700022
: None
Fatigue of single- and double-rivet self-piercing riveted lap joints
:   Iyer, K; Hu, SJ; Brittman, FL; Wang, PC; Hayden, DB; Marin, SP
:NOV 2005
: Fatigue & Fracture of Engineering Materials & Structures
  28
  997
  1007
: WOS:000232802500006
: None
A computational design-of-experiments study of hemming processes for automotive aluminium alloys
:   Lin, G; Iyer, K; Hu, SJ; Cai, W; Marin, SP
:OCT 2005
: Proceedings of the Institution of Mechanical Engineers Part B-Journal of Engineering Manufacture
  219
  711
  722
: WOS:000233571400001
: None
Prediction of electrical contact resistance for anisotropic conductive adhesive assemblies
:   Chin, M; Iyer, KA; Hu, SJ
:JUN 2004
: Ieee Transactions on Components and Packaging Technologies
  27
  317
  326
: WOS:000222428900011
: None
Peak contact pressure, cyclic stress amplitudes, contact semi-width and slip amplitude: relative effects on fretting fatigue life
:   Iyer, K
:MAR 2001
: International Journal of Fatigue
  23
  193
  206
: WOS:000167061800002
: None
Solutions for contact in pinned connections
:   Iyer, K
:DEC 2001
: International Journal of Solids and Structures
  38
  9133
  9148
: WOS:000172609100010
: None
Analyses of contact pressure and stress amplitude effects on fretting fatigue life
:   Iyer, K; Mall, S
:JAN 2001
: Journal of Engineering Materials and Technology-Transactions of the Asme
  123
  85
  93
: WOS:000168572500010
: None
Influence of interference and clamping on fretting fatigue in single rivet-row lap joints
:   Iyer, K; Rubin, CA; Hahn, GT
:OCT 2001
: Journal of Tribology-Transactions of the Asme
  123
  686
  698
: WOS:000171576200005
: None
Effects of cyclic frequency and contact pressure on fretting fatigue under two-level block loading
:   Iyer, K; Mall, S
:APR 2000
: Fatigue & Fracture of Engineering Materials & Structures
  23
  335
  346
: WOS:000087647700006
: None
Analysis of fatigue and fretting of three-dimensional, single and double rivet-row lap joints
:   Iyer, K; Bastias, PC; Rubin, CA; Hahn, GT; Cook, R; Poole, P
:1997
: Icaf 97: Fatigue in New and Ageing Aircraft, Vols I and Ii
  --
  855
  869
: WOS:000080598500050
: None
ANALYSIS OF FRETTING CONDITIONS IN PINNED CONNECTIONS
:   IYER, K; HAHN, GT; BASTIAS, PC; RUBIN, CA
:MAR 1995
: Wear
  181
  524
  530
: WOS:A1995QP27000013
: None
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