Updated 11/15/01
Technology Demonstration
Overview
The Kepler Mission depends on the ability
to reliably measure the very small relative change in brightness
of a star caused by the transit of an Earth-size planet. We have
constructed a high-fidelity Testbed Facility of the end-to-end
photometry system. This has been used to show that under all
of the expected operating conditions which can add noise to the
measurements, the signature of an Earth-size transit is readily
detectable.
This page provides an overview of the the
technology demonstration that has been performed. It is followed
by a page on the laboratory facility that has been constructed
and then by a page that discusses the results.
To perform an end-to-end system test of the
Kepler Mission a laboratory facility has been built to
replicate the elements that will compose the flight system. The
laboratory system consists of:
- A simulated star field that represents all
of the features of the real sky that are important for ensemble
photometry;
- A photometer that operates and has the same
characteristics of the flight photometer, including:
- Fast optics to focus the star field onto
the CCD detector,
- A commercially available CCD that could be
used in the flight system,
- High speed readout electronics (operating
at 1 mega pixel/sec/amp) to process the data as if onboard the
spacecraft, and
- Ground software used to produce the light
curves, detect transits and evaluate the precision of the data.
- A structure that provides thermal, mechanical
and RF isolation and stability from the laboratory environment.
The objective of the technical demonstration
was to show that this end-to-end system can maintain the required
relative precision over a period of time necessary to detect
transits when all of the confounding noise factors are included.
Note that the critical parameter is only relative precision,
that is, the ratio of the flux of one star relative to the fluxes
of many nearby stars read at the same time on the same CCD.
The topics covered in the following pages
include:
Objectives
Laboratory Facility Description
Construction Photographs
Test Criteria, System
Characterization and Data Processing
Tech Demo Test Results
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