Astrometric and Photometric Observations of 1996 PW, a Very Eccentric Asteroid
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This paper gives an overview of the Micro-Precision Interferometer (MIP) testbed and its major achievements to date related to mitigating risk for future spaceborne optical interferometer missions.
The MicroPrecision Interferometer Testbed (MIP) at JPL is a dynamically and dimensionally representative hardware model of a future spaceborne optical interferometer.
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A system that automatically regulates the concentration of glucose or pH in a liquid culture medium that is circulated through a rotating-wall perfused bioreactor is described. Another system monitors the concentration of oxygen in the culture medium.
The Micro-Arcsecond Metrology (MAM) testbed is a ground-based system of optical and electronic equipment for testing components, systems, and engineering concepts for the Space Interferometer Mission (SIM) and similar future missions, in which optical interferometers will be operated in outer space. In addition, the MAM testbed is of interest in its own right as a highly precise metrological system. The designs of the SIM interferometer and the MAM testbed reflect a requirement to measure both the position of the starlight central fringe and the change in the internal optical path of the interferometer with sufficient spatial resolution to generate astrometric data with angular resolution at the microarcsecond level. The internal path is to be measured by use of a small metrological laser beam of 1,319-nm wavelength, whereas the position of the starlight fringe is to be estimated by use of a charge-coupled-device (CCD) image detector sampling a large concentric annular beam. For the SIM to succeed, the optical path length determined from the interferometer fringes must be tracked by the metrological subsystem to within tens of picometers, through all operational motions of an interferometer delay line and siderostats. The purpose of the experiments performed on the MAM testbed is to demonstrate this agreement in a large-scale simulation that includes a substantial portion of the system in the planned configuration for operation in outer space. A major challenge in this endeavor is to align the metrological beam with the starlight beam in order to maintain consistency between the metrological and starlight subsystems at the system level. The MAM testbed includes an optical interferometer with a white light source, all major optical components of a stellar interferometer, and heterodyne metrological sensors. The aforementioned subsystems are installed in a large vacuum chamber in order to suppress atmospheric and thermal disturbances. The MAM is divided into two distinct subsystems: the test article (TA), which is the interferometer proper, and the inverse interferometer pseudo-star (IIPS), which synthesizes the light coming from a distant target star by providing spatially coherent wavefronts out of two mirrors, separated by the MAM baseline, that feed directly into two siderostats that are parts of the TA. The two feed mirrors of the IIPS are articulated (in translation and tilt) in order to simulate stars located at different orientations in space, while still illuminating the TA siderostats. The spectrum of the simulated starlight of the IIPS corresponds to that of a blackbody at a temperature of about 3,100 K.
This paper describes a benchmark to assess performance of six-axis vibration isolation systems.
This paper discusses the vibration isolation problem as it applies to spaceborne
This paper presents initial results that demonstrate the end-to-end operation of the Micro-Precision
This paper describes the relationship between the Space Interferometer Mission (SIM) and the MicroArcsecond Measurment Testbed (MAM). MAM is necessary because differences exist between starlight and the metrology measurements through the SIM instrument optical path.
We predict the contribution to the on-orbit residual tip-tilt performance due to the reaction wheel disturbance, for different isolater and closed loop optics configurations for the Space Interferometer Mission (SIM).
We investigate how the Space Interferometry Mission (SIM) will be able to meet its instrument astrometric pointing requirements.
The paper presents a partial account of control lessons learned during the development of the Micro-Precision Interferometer (MIP) testbed.
This paper validates the integrated modeling methodology used for design and performance evaluation of complex opto-mechanical systems, particularly spaceborne interferometers. The methodology integrates structural modeling, optical modeling, and control system design into a common environment, the Integrated Modeling of Optical Systems (IMOS) software package.
This paper validates the integrated modeling methodology used for design and performance evaluation of complex opto-mechanical systems, particularly spaceborne interferometers.
This paper will compare the performance of various algorithms using the MAM data, and will aid in our recommendation of how the SIM flight system should process the science and guide interferometer data.