From: Ames Research Center
Posted: Monday, February 14, 2005
NASA Ames Research Center, located in California's Silicon Valley, has awarded a new contract to Ball Aerospace and Technologies Corp. (BATC) of Boulder, Colo., to design, fabricate, assemble and test a photometer for the Kepler mission.
The not-to-exceed value of this letter contract is $13.4 million; the estimated value of the total contract is $75.1 million, which is part of a five-phased acquisition. A cost-plus-incentive-fee contract is anticipated, with a three-year period of performance that does not include any contract options.
Under the terms of the contract, Ball Aerospace is responsible for designing, fabricating, integrating, testing and commissioning the scientific instrument called the photometer. Under a separate contract, the corporation also is responsible for the three-axis stabilized spacecraft designed to operate in deep space.
The Kepler mission is the first space mission specifically designed to detect Earth-size planets orbiting solar-like stars in their habitable zone. The habitable zone is that distance from a star where liquid water could exist on the surface of the planet.
Scheduled to launch in October 2007 on a Boeing Delta II expendable launch vehicle, Kepler is the 10th mission in NASA's Discovery program series. Project scientists will survey our extended solar neighborhood to detect and characterize hundreds of terrestrial and larger planets to provide a greater understanding of planetary systems.
The photometer will be used to measure the very small changes in a star's brightness caused by the repeated, periodic 'transit' of a planet in front of its star, as viewed from our solar system, similar to the transit of Venus in front of the sun in June 2004. The focal plane of the photometer will be made up of light-sensing charge coupled devices (CCDs) similar to those in a digital camera, but much larger, with a total of 100 megapixels.
The photometer will survey a single, large patch of sky for the entire four-year mission, an area equivalent in size to two open hands held together at arms' length. The location in the sky is in the Cygnus-Lyra regions, between the very bright stars Vega and Deneb. The photometer will produce light curves, not images, for at least 100,000 stars simultaneously. It is the equivalent of a 100,000-channel light meter, hence the term photometer.
By searching for a sequence of 'transits' in the light curves from each star, scientists will determine the planet's orbital period. From the depth of the 'transit' and knowing the size, mass and temperature of the star, the team can calculate the planet's size and the planet's characteristic temperature. Using Kepler's Third Law, which can be paraphrased as "For circular orbits, the distance of a planet from its star is proportional to the 2/3 root of the planet's orbital period," the scientists will be able to calculate the planet's orbit. The scientists then will be able to determine if the planet is located in the habitable zone, where liquid water can exist on the surface of the planet.
Led by the project's principal investigator, William Borucki, and the project's deputy principal investigator, David Koch, both of NASA Ames, the science team is comprised of 27 scientists from 15 institutions in the United States, Canada and Denmark.
NASA Ames will manage the photometer contract, while NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., will manage the spacecraft contract. JPL is responsible for the project's overall mission development through launch and commissioning. NASA Ames will manage the mission's operations phase and lead the scientific analysis and interpretation of data. Ball Aerospace will operate the spacecraft throughout the mission for NASA.
Scientists expect this mission will detect numerous Earth-size planets around solar-like stars and hundreds to thousands of planets of various sizes, in various orbits around a wide variety of stars.
Further details about the Kepler mission can be found at: http://Kepler.NASA.gov
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