&lt;title&gt;Lockheed Martin team's Next Generation Space Telescope (NGST) reference architecture&lt;/title&gt;

Martin, F.; Lesyna, L.; LeRoy, Robert J.; Menzel, Michael T.; A., Hyatt, Benjamin; Triebes, K.; Rudiger, C.; Stier, M. T.; Cox, Charles D.; Delp, Charles D.; Hachkowski, Roman; Hardman, George B.; Keane, Michael; MacFarlane, Malcolm J.; Mordino, A.; Krim, Michael H.

doi:10.1117/12.394043

Cited by 4 publications

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“…Id,(r) = (0 *Hd)(r) + fldfr) d = 1, ...,ND (1) where vector r is the image and object angular coordinate, * represents the convolution operator, Hd is the point spread function in the plane number d, and d the additive noise.…”

Section: Cophasing With Phase Diversity 21 Principle Of Phase Divermentioning

confidence: 99%

Cophasing a wide field multi-aperture array by phase-diversity: influence of aperture redundancy and dilution

et al. 2003

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Future high-resolution space telescopes will use discontinuous apertures, either primary segments ("Fizeau" case) or sub-telescopes (" Michelson" case) . One of the most critical points in the operation of such instruments will be the cophasing of the sub-apertures. Cophasing sensors are available on ground interferometers, allowing sub-aperture piston/tip/tilt measurement on unresolved or slightly resolved stars. But when observing a very extended object, such as the Earth as seen from space, no reference star can be found in the field. In this case, the cophasing measurement must be derived from the observed object itself, which is a major issue for extended objects.Phase diversity is one of the very few solutions to this problem. Phase diversity consists in the joint estimation of the object and the instrument aberrations from the analysis of several images obtained with different but perfectly known aberrations, for example the focal image and a slightly defocused image. Theoretical analysis and numerical simulations were carried out to investigate how our phase diversity algorithm behaves when estimating sub-aperture piston and tip/tilt in various conditions. Our study shows that the aperture configuration has a major impact on performance. For diluted apertures, when the optical transfer function has zeros within the frequency domain of interest, it can be shown that at least two possible solutions can be derived by phase diversity. For redundant apertures, when several pairs of subaperture contribute to the same spatial frequency, the piston or tip/tilt estimation is degraded for sub-apertures contributing to redundant frequencies.

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Section: Cophasing With Phase Diversity 21 Principle Of Phase Divermentioning

confidence: 99%

Cophasing a wide field multi-aperture array by phase-diversity: influence of aperture redundancy and dilution

et al. 2003

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“…[12][13][14][15] An important example of a MOS in space will be found at the Next Generation Space Telescope (NGST) which is scheduled for launch in 2008. [16][17][18] This telescope is planned to be equipped with a Near Infrared MOS, working in the wavelength range from 1 µm to 5 µm. The NGST-MOS will have a spatial resolution in the order of 2000 × 2000 pixels.…”

Section: Introductionmentioning

confidence: 99%

Integral field and multi-object spectrometry with MEMS

Wuttig¹,

Riesenberg²,

Nitzsche³

2002

SPIE Proceedings

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Multi object spectrometers measure spectra of multiple objects simultaneously. Besides others, e.g. fiber positioning systems, there is a class of multi object spectrometers which is based on a dispersing imaging optics in connection with a slit masks. Two considered approaches for reconfigurable slit masks are two-dimensional MEMS arrays, such as micro mirror or micro shutter arrays, and slit positioning devices. After an introduction to multi object spectrometry with dispersing imaging optics we calculate the effective multiplex capabilities of multi object spectrometers based on 2D MEMS and on slit positioning devices for randomly distributed objects. The observation efficiency of multi object spectrometers based on 2D MEMS is compared to integral field spectrometers and to multi object spectrometers based on slit positioning devices. We find that for typical applications the efficiency of the slit positioning approach is nearly as good as the efficiency of the 2D MEMS approach. This makes slit positioning systems a serious alternative solution to 2D MEMS devices as long as they are easier to get.

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“…When designing the NGST they assumed that the total weight of the telescope must not exceed 3300 kg [23][24][25], the total weight of its primary mirror must be less than 800 kg, and its areal density not more than 15 kg/m2. The last is determined by the density of the mirror itself, its support structure, actuators et al.…”

Section: Super-light Mirrorsmentioning

confidence: 99%

“…Thus, the areal density of the whole mirror must be less than 15 kg/m2. The NGST as a whole must comprise the following basic units [23] The NGST is to be launched by rockets Atlas V-531 [22] or Atlas IIAS [20]. Designing the NGST will involve development of technologies of OTA, ultra-light cryogenic mirrors, cryogenic actuators, a cryogenic deformable mirror, deployable structures, systems of controlling wavefronts and some other [24].…”

Section: Space Telescopes and Their Projectsmentioning

confidence: 99%

“…As for space telescopes the segmentation is necessary in principle because restrictions of modern launching systems by diameter of the payload of 4-5 m [35]. For orbiting the total weight of a space telescope must not exceed several tons [22].When designing the NGST they assumed that the total weight of the telescope must not exceed 3300 kg [23][24][25], the total weight of its primary mirror must be less than 800 kg, and its areal density not more than 15 kg/m2. The last is determined by the density of the mirror itself, its support structure, actuators et al.…”

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confidence: 99%

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Study Of Pre-Shaped Membrane Mirrors And Electrostatic Mirrors With Nonlinear-Optical Correction

Dimakov¹,

Emel'yanov²

2002

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget,, Washington, DC 20503. AGENCY USE ONLY (Leave blank)2. REPORT DATE This report results from a contract tasking Research Institute for Laser Physics as follows: The aim of this work is to improve low-weight membrane mirror characteristics intended for relaying laser communication beams in space. Such systems would use a non-linear-optical corrector to correct surface figure and other optical aberrations. The analytical part of this project is aimed at estimating the feasibility of designing the mirrors based on the pre-shaped membranes. This evaluation will give a clear understanding of the approaches to forming super-light mirrors as well as of the problems anticipated in creating this new generation of space mirrors. In the course of the experimental work, a low-weight mirror model based on the pre-shaped membrane will be fabricated, and its optical characteristics will be studied. It is expected that the characteristics predicted theoretically will be observed experimentally. The first quarterly report on project 2103p (ISTC 00-7032), entitled "Study of pre-shaped membrane mirrors and electrostatic mirrors with nonlinear-optical correction." Large telescopes and super light mirrors OverviewNowadays a number of scientific and practical fields of activity need solutions of the problems requiring high-resolution of both ground and space based telescopes with substantial space penetrating power, namely ones with large aperture mirrors.First of all, these high-resolution physical instruments are required for astronomic observations. For example, the National Research Council of the National Academy of Sciences of the USA states the strategic tasks of astronomic observations as follows: "We must use the universe as a laboratory -a unique laboratory -for probing the laws of physics in regimes not accessible on Earth, such as the very early universe or near the event horizon of a black hole." "We must search for life beyond the Earth and, if it is found, determine its nature and its distribution. And finally, we must develop a conceptual framework that accounts for all that we have observed," the report says [1]. Note that at present the requirements to a telescope for some tasks [2] are the resolution of the order of 10 -3 arcsec and space penetrating power of stars of the 35th-38th magnitude. This means that a primary mirror must be of the order of 100m in diameter.Obviously, high-resolution...

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<title>Lockheed Martin team's Next Generation Space Telescope (NGST) reference architecture</title>

Cited by 4 publications

References 0 publications

Cophasing a wide field multi-aperture array by phase-diversity: influence of aperture redundancy and dilution

Cophasing a wide field multi-aperture array by phase-diversity: influence of aperture redundancy and dilution

Integral field and multi-object spectrometry with MEMS

Study Of Pre-Shaped Membrane Mirrors And Electrostatic Mirrors With Nonlinear-Optical Correction

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