Engineering topics

Russell, Kevin

Publications and source records attributed to Russell, Kevin.

11 records

NASA NTRS2004

James Webb Space Telescope (JWST) Primary Mirror Material Selection

The James Webb Space Telescope (JWST) conducted a phase down select process via the Advanced Mirror System Demonstrator (AMSD) project to assess the Technology Readiness Level of various candidate mirror materials. This process culminated in the selection of Beryllium as the JWST primary mirror material. This paper outlines the mirror evaluation process, defines the selection criteria and summarizes the candidate mirror's performances.

Stahl, H. Philip↗

NASA NTRS2002

Radius of Curvature Measurements: An Independent Look at Accuracy Using Novel Optical Metrology

The AMSD (Advanced Mirror System Demonstrator) program mirror specifications include the ability to manufacture the mirror to a radius of curvature of 10 m +/- 1 mm and to control its radius at 30K to the same specification. Therefore, it is necessary for the Government Team to be able to measure mirror radius of curvature to an accuracy of better than 0.5 mm. This presentation discusses a novel optical metrology system for measuring radius of curvature.

Taylor, Bryon↗

NASA NTRS2002

AMSD Test Plan

The overall government plan to verify compliance of AMSD mirror systems to the specifications as given in the contract Statement of Work will be presented. The plan will address test requirements, test hardware, AMSD-XRCF interfacing, government vs contractor responsibilities, tests to be carried out, test conduction, and test data reduction & reporting. Issues regarding input to the plan and schedule of plan milestones will also be addressed.

Hadaway, James↗

NASA NTRS2002

Overview of MSFC AMSD Integrated Modeling and Analysis

Structural, thermal, dynamic, and optical models of the NGST AMSD mirror assemblies are being finalized and integrated for predicting cryogenic vacuum test performance of the developing designs. Analyzers in use by the MSFC Modeling and Analysis Team are identified, with overview of approach to integrate simulated effects. Guidelines to verify the individual models and calibration cases for comparison with the vendors' analyses are presented. In addition, baseline and proposed additional scenarios for the cryogenic vacuum testing are briefly described.

Cummings, Ramona↗

NASA NTRS2002

Radius of Curvature of Off-Axis Paraboloids

We present several methods for measuring the vertex radius of curvature of off-axis paraboloidal mirrors. One is based on least-squares fitting of interferometer output, one on comparison of sagittal and tangential radii of curvature, and another on measurement of displacement of the nulled test article from the ideal reference wave. Each method defines radius of curvature differently and, as a consequence, produces its own sort of errors.

Robinson, Brian↗

NASA NTRS2002

AMSD Figure Certification Plan

The method planned for the surface figure error measurement of the AMSDs at the XRCF will be discussed. Alignment, surface figure measurement, gravity effects, vibration & temperature environment effects, total error analysis, and data output will be discussed.

Reardon, Pat↗

NASA NTRS2002

AMSD Cryo Actuator Testing

The actuator technology required for AMSD and subsequently NGST are critical in the successful development for future cryogenic systems. Kodak has undertaken an extensive test plan to determine the performance of the force actuators developed under the AMSD program. These actuators are currently in testing at MSFC and are expected to finish this test cycle in early June 2002.

Mullette, Mark↗

NASA NTRS2002

Kodak AMSD Mirror Development Program

The Advanced Mirror System Demonstration Program is developing minor technology for the next generation optical systems. Many of these systems will require extremely lightweight and stable optics due to the overall size of the primary mirror. These segmented, deployable systems require new technology that AMSD is developing. The on-going AMSD program is a critical enabler for Next Generation Space Telescope (NGST) which will start in 2002. The status of Kodak's AMSD mirror and future plans will be discussed with respect to the NGST program.

Matthews, Gary↗

NASA NTRS2002

Kodak AMSD Cryogenic Test Plans

NGST will be an IR based optical system that will operate at cryogenic temperatures. As part of the AMSD program, Kodak must demonstrate the ability of our system to perform at these very cold temperatures. Kodak will discuss the test approach that will be used for cryogenic testing at MSFC's XRCF.

Matthews, Gary↗

NASA NTRS2001

Ball Semi-Rigid Advanced Mirror System Demonstrator (AMSD)

The AMSD Program is to design, fabricate, and test a 1.4-m point-to-point hexagon mirror system. The Ball semi-rigid approach will be described and its current status presented, The mirror system includes a lightweighted beryllium mirror that is attached through flexures and actuators to a composite reaction structure enabling optical performance at ambient and cryogenic temperatures and allowing changes of curvature to be imposed via actuation. This program is administered through NASA MSFC and is jointly funded by NASA, the USAF, and the NRO.

Kendrick, Stephen↗

NASA NTRS2000

Metrology Mount and Optics Mandrels

This document is the Final Report for NASA Grant NAG8-1198 from NASA Marshall Space Flight Center (MSFC) to the Smithsonian Astrophysical Observatory (SAO). The Grant is entitled "Metrology Mount and Optics Materials." This final report is required by the terms of the Grant. The period of performance was from September 15, 1995 through January 14, 1999. Total funding received by SAO from MSFC for this effort was, $254,000. Mr. Lester Cohen carried out most of the work at SAO, but received limited support from other engineers, technicians, and designers. Dr. Harvey Tananbaum, the Principal Investigator for the grant provided overall direction and work- assessment. The Grant has had two funding augmentations to its basic amount and has, over time, emphasized three different research areas - each of which has been an extension of earlier research. The research activity was in 2 areas: (1) Expert opto-structural studies related to separation mechanics and effects of electro formed nickel X-ray mirrors. and (2) Design, fabrication and evaluation of a low force metrology and assembly station for light weight full shell electroformed X-ray mirrors.

Tananbaum, H.↗