Dr. Alain C. Carrier Profile

Dr. Alain C. Carrier

Research Scientist Senior Fellow at Lockheed Martin Corp

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Author

Publications (7)

Proceedings Article | 24 July 2014 Paper

Arcus: an ISS-attached high-resolution x-ray grating spectrometer

R. Smith, M. Ackermann, R. Allured, M. Bautz, J. Bregman, J. Bookbinder, D. Burrows, L. Brenneman, N. Brickhouse, P. Cheimets, A. Carrier, M. Freeman, J. Kaastra, R. McEntaffer, J. Miller, A. Ptak, R. Petre, G. Vacanti

Proceedings Volume 9144, 91444Y (2014) https://doi.org/10.1117/12.2062671

KEYWORDS: X-rays, Stars, Charge-coupled devices, Sensors, Control systems, Spectroscopy, Diffraction gratings, Galactic astronomy, Silicon, Spectral resolution

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Proceedings Article | 12 October 2004 Paper

Damping characteristics of composite petal structure for an 8-m diameter telescope at cryogenic temperature

Alain Carrier, Bruce Romney, Roger Mihara

Proceedings Volume 5487, (2004) https://doi.org/10.1117/12.552752

KEYWORDS: Cryogenics, Data modeling, Composites, Telescopes, Space telescopes, Shape analysis, Observatories, Temperature metrology, Acoustic emission, Atmospheric propagation

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Concerns have been raised in the engineering community about the potentially extremely low levels of structural damping in structures at cryogenic temperatures. Experiments conducted on material coupons have shown that material damping at those temperatures can be orders of magnitude lower than that at room temperature. Whether structural damping in built-up structures at those temperatures can be that low is unknown, but if it was, the telescope resonances could exacerbate microdynamics originating from the structure itself and residual vibrations propagating from the instrument module to the telescope. Since the effect of those vibrations might not be compensated for optically, the observatory might not meet its wavefront and jitter error budgets. The structural damping characteristics of built-up structures in the micrometer to nanometer regime and at cryogenic temperatures are to a large extent unknown. Characterization on structures traceable to future flight designs is therefore necessary to develop an understanding of these characteristics, as well as devise means to mitigate those effects. To address those concerns and to reduce the technical risks in these areas, Lockheed Martin tested the dynamics characteristics of its Single Petal Testbed (SPT) flight-like petal structure at full-scale, from room temperature down to -175C (98K). The SPT was designed by the Lockheed Martin Advanced Technology Center and fabricated by Programmed Composites Inc. Significant changes in dynamics characteristics with temperature were observed, but primarily in mode shapes as opposed to modal frequencies and modal dampings. The modal damping remained fairly constant throughout the temperature range and, to the extent changes could be detected, the trends were more towards an increase than a decrease in damping at 98K, which was highly unexpected. A detailed analysis of these results extracted from dynamics tests conducted during the cool down portion of the last thermal cycle is presented in this report. The levels of damping observed in the built-up petal structure are 10 to 20 times higher than those measured by Marie Levine at JPL on all-composite coupons of the petal panels provided by Lockheed Martin.

Proceedings Article | 5 March 2003 Paper

Development and microdynamics characterization of a deployable petal assembly at full scale

Alain Carrier, Jean-Noel Aubrun, Robert Clappier, Timothy Hilby, Kenneth Lorell, Bruce Romney, Larry Sokolsky, Jim Uphoff

Proceedings Volume 4850, (2003) https://doi.org/10.1117/12.461556

KEYWORDS: Mirrors, Mirror structures, Position sensors, Interfaces, Cryogenics, Optical fabrication, Space telescopes, Actuators, Telescopes, Sensors

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Proceedings Article | 5 March 2003 Paper

Development and demonstration of a precision latch for deployable optical systems

Alain Carrier, Jean-Noel Aubrun, Patrick Champagne, Craig Hom, Kenneth Lorell, Roger Mihara

Proceedings Volume 4850, (2003) https://doi.org/10.1117/12.461549

KEYWORDS: Mirrors, Interfaces, Finite element methods, Temperature metrology, Cryogenics, Space telescopes, Sensors, Kinematics, Phase modulation, Space operations

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The Lockheed Martin/Advanced Technology Center (LM/ATC) developed a lightweight, compact, high-load capable and yet high precision latch for use on deployable optical systems such as the Next Generation Space Telescope (NGST). The design allows precise self-centering and control of the stiffness at the latch interface. It also incorporates unique capabilities to evaluate the effects of gravity loads, latch preload level, creep, and very low vibration loads on the dynamics and microdynamics of the deployed instrument. The stiffness, nonlinearity and hysteresis characteristics of the latch and its catch flexure assembly were thoroughly tested in 6 axes down to the nanometer level at room temperature using the LM/ATC Compliance Measurement Device. The latch is stiff enough to hold an NGST-size mirror segment cantilevered against gravity allowing only small gravity sag when the primary mirror is horizontal, thus enabling end-to-end performance verification in 1-G in that orientation. The latch hysteresis is less than 1.0 nm/N under mechanical loads less than 25 N, which meets the NGST stability requirements with significant margin (20 nm at the tip of the petal in space environment). Several of these latches were integrated and demonstrated at the petal assembly level on a Single Petal Test-bed and the experimental results obtained on that test-bed are consistent with the component level results described in this report. We experimentally demonstrated that the latch engagement performance is not affected by exposure to cryogenic temperatures down to 20K, as required for use of the device on cryogenic infrared optical instruments such as NGST. A structural model of the latch was developed using Finite Element Analysis. Good correlation was obtained between the linear components of the analytical and of the experimental results: the model can therefore reliably be used in future NGST or other mission design efforts. This paper includes a brief description of the LM/ATC latch hardware and its principle of operation as well as the results of the modeling and the experimental characterization work performed on that hardware in the NGST Phase I formulation.

Proceedings Article | 12 May 1995 Paper

Canceling vibrations with smart materials: a case study

Mark Regelbrugge, Alain Carrier, William Dickson

Proceedings Volume 2447, (1995) https://doi.org/10.1117/12.209351

KEYWORDS: Actuators, Ceramics, Signal attenuation, Optical isolators, Control systems, Smart materials, Interfaces, Vibration control, Space operations, Instrument modeling

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Proceedings Article | 31 May 1994 Paper

Experiments in modeling and control of the ASCIE segmented reflector

Alain Carrier, Jean-Noel Aubrun

Proceedings Volume 2201, (1994) https://doi.org/10.1117/12.176123

KEYWORDS: Control systems, Reflectors, Data modeling, Systems modeling, Mirrors, Actuators, Astronomy, Adaptive optics, Sensors, Performance modeling

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Proceedings Article | 10 July 1992 Paper

Modal characterization of the ASCIE segmented optics test bed: new algorithms and experimental results

Alain Carrier, Jean-Noel Aubrun

Proceedings Volume 1696, (1992) https://doi.org/10.1117/12.138149

KEYWORDS: Actuators, Sensors, Optimization (mathematics), Control systems, Algorithm development, Systems modeling, Matrices, Space telescopes, Complex systems, Optical testing

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