The goal of the Terrestrial Planet Finder (TPF) mission is to detect and characterize terrestrial exoplanets at visible wavelengths. One approach combines an 8m by 3.5m aperture telescope with a coronagraph (TPF-C) to obtain the required planet to parent star contrast. The proposed design places severe constraints on alignment tolerances and requires optics of the highest possible quality. The integration, test and verification of the observatory will require extraordinary procedures. This paper is an initial attempt to outline a plausible program to verify before launch the in-orbit performance requirements.
The Terrestrial Planet Finder-Coronagraph (TPF-C) is a NASA exploration mission to directly detect and characterize terrestrial exoplanets at visible wavelengths. The TPF-C observatory must be able to distinguish a planet that is more than 10 orders of magnitude fainter than its parent star at a separation of 75 milli-arc-seconds (mas). Coronagraphic detection requires a large aperture telescope to resolve the exoplanet from its star, and extreme stability during detection and characterization observations. This paper discusses the requirements and trade studies leading to the current baseline optical design for the TPF-C telescope. The current baseline design is summarized and its prescription is presented.
The Terrestrial Planet Finder Coronagraph (TPF-C) is conducting pre-formulation design and analysis studies based on a 8x3.5m elliptical aperture, light-weight primary mirror feeding an internally occulted (Lyot) coronagraph. The primary mirror has challenging static and dynamic performance requirements. We report on recent trade studies and concepts including open- and closed-back mirror blank designs and comparisons of thermal and mechanical performance; aperture shape alternatives to better match the coronagraph application with weight, packaging, and fabrication constraints; and mirror material trades.
Several designs of filters for use in vacuum UV imaging systems are discussed. These designs incorporate all reflective optics,and are characterized by comparatively high in-band throughout, very low out-of-band transmission and sub-arcsecond spatial resolution. In addition, they an be tuned over ranges useful for vacuum UV astronomical observations. Results from a simplified laboratory version of the filters intended to prove the concept are presented.
A design for an advanced camera (AC) third-generation Hubble Space Telescope scientific instrument is discussed. The AC is a three-channel spectrophotometric camera with wavelength sensitivity from 115-1000 nm. The AC, if selected, would be launched in 1999 for installation on HST. The axial bay design incorporates optical correction for the aberrated HST primary mirror and evolutionary advances in imaging capability.
Current uses of the MAMA detector which utilize the photon time-tagging capabilities of these detectors are reported. These applications currently include image stabilization by means of post-processing corrections of platform drift and speckle interferometry. The initial results of a sounding rocket experiment to obtain UV images of NGC 6240 and results from speckle interferometry of Neptune's moon Triton are presented.