Engineering topics

Gappinger, R. O.

Publications and source records attributed to Gappinger, R. O..

4 records

NASA NTRS2008

Terrestrial Planet Finder Interferometer: 2007-2008 Progress and Plans

This paper provides an overview of technology development for the Terrestrial Planet Finder Interferometer (TPF-I). TPF-I is a mid-infrared space interferometer being designed with the capability of detecting Earth-like planets in the habitable zones around nearby stars. The overall technology roadmap is presented and progress with each of the testbeds is summarized. The current interferometer architecture, design trades, and the viability of possible reduced-scope mission concepts are also presented.

formation flying↗

NASA NTRS2006

Terrestrial Planet Finder Interferometer Technology Status and Plans

A viewgraph presentation on the technology status and plans for Terrestrial Planet Finder Interferometer is shown. The topics include: 1) The Navigator Program; 2) TPF-I Project Overview; 3) Project Organization; 4) Technology Plan for TPF-I; 5) TPF-I Testbeds; 6) Nulling Error Budget; 7) Nulling Testbeds; 8) Nulling Requirements; 9) Achromatic Nulling Testbed; 10) Single Mode Spatial Filter Technology; 11) Adaptive Nuller Testbed; 12) TPF-I: Planet Detection Testbed (PDT); 13) Planet Detection Testbed Phase Modulation Experiment; and 14) Formation Control Testbed.

Terrestrial Planet Finder (TPF)↗

NASA NTRS2006

Measurement of Spatial Filtering Capabilities of Single Mode Infrared Fibers

Spatial filtering is necessary to achieve deep nulls in optical interferometer and single mode infrared fibers can serve as spatial filters. The filtering function is based on the ability of these devices to perform the mode-cleaning function: only the component of the input field that is coupled to the single bound (fundamental) mode of the device propagates to the output without substantial loss. In practical fiber devices, there are leakage channels that cause light not coupled into the fundamental mode to propagate to the output. These include propagation through the fiber cladding and by means of a leaky mode. We propose a technique for measuring the magnitude of this leakage and apply it to infrared fibers made at the Naval Research Laboratory and at Tel Aviv University.

infrared↗

NASA NTRS2003

Mid-infrared nuller for Terrestrial Planet Finder: design progress and results

Nulling interferometry shows promise as a technique enabling investigation of faint objects such as planets and exo-zodiacal dust around nearby stars. At Jet Propulsion Laboratory, a nulling beam combiner based on a design built for the Keck Observatory in Hawaii has been used to pursue deep and stable narrowband nulls. We describe the design and layout of the Modified Mach Zehnder TPF nuller, and the results achieved in the laboratory to date. We report the stabilized 900,000 nulls achieved using a CO2 laser, and discuss the performance limitations and way forward to the deep, broadband nulls required for a space-borne nulling interferometer mission. We show briefly the results from Keck breadboard experiments: broadband transient nulls centered around 10.6 micron have been achieved ranging between 17500 at 18% bandwidth and 7500:1 at 29% bandwidth.

Serabyn, E.↗