Design Study for a Planet-Finding Space Interferometer

The characterization of earthlike planets that may be orbiting nearby stars will require large observatories capable of detecting a small number of planet photons and separating them from the much larger flux from the parent star. One approach to this is to employ nulling interferometry on a space-based platform utilizing a number of spacecraft. At the Jet Propulsion Laboratory, a linear dual chopped Bracewell array design was studied in depth while in Europe various two-dimensional designs were discussed. This study looks in a little more depth at the design issues for one of the European concepts and concludes that the concept has promise for a significant reduction in spacecraft complexity and mass and therefore would result in a lower costmission.