Kepler Technology Demonstrator (KTD)

NASA's Kepler Space Telescope utilized a photometer composed of an array of 42 CCDs (charge coupled devices). The photometer is designed to detect transit patterns of planets orbiting stars. Before NASA would approve such an instrument, however, they required proof that a photometer with the precision required to find Earth-size planets could be developed that would operate satisfactorily with the types of noise and interference encountered in orbit.

This testbed was designed to conduct an end-to-end laboratory test of the photometric method for finding terrestrial-size planets. It includes a simulated star field with a light source to simulate the solar spectrum, fast optics to simulate the telescope, a CCD similar to those that were used on the spacecraft, and was connected to computers to perform the onboard CCD control and data handling. The test structure was thermally isolated, and noise sources were introduced in a controlled manner and evaluated. Transits were simulated by passing an electrical current through fine wires placed across the star apertures in the star field, causing thermal expansion of the wire and a resulting decrease in stellar brightness.

The Kepler Technology Demonstrator was transferred to the Museum by NASA in 2021.