Opto-mechanical design of the vacuum compatible EXCEDE's mission testbed

In this paper we describe the opto-mechanical design, tolerance error budget an alignment strategies used to build the Starlight Suppression System (SSS) for the Exoplanetary Circumstellar Environments and Disk Explorer (EXCEDE) NASA's mission. EXCEDE is a highly efficient 0.7m space telescope concept designed to directly image and spatially resolve circumstellar disks with as little as 10 zodis of circumstellar dust, as well as large planets. The main focus of this work was the design of a vacuum compatible opto-mechanical system that allows remote alignment and operation of the main components of the EXCEDE. SSS, which are: a Phase Induced Amplitude Apodization (PIAA) coronagraph to provide high throughput and high contrast at an inner working angle (IWA) equal to the diffraction limit (IWA = 1.2 l/D), a wavefront (WF) control system based on a Micro-Electro-Mechanical-System deformable mirror (MEMS DM), and low order wavefront sensor (LOWFS) for fine pointing and centering. We describe in strategy and tolerance error budget for this system, which is especially relevant to achieve the theoretical performance that PIAA coronagraph can offer. We also discuss the vacuum cabling design for the actuators, cameras and the Deformable Mirror. This design has been implemented at the vacuum chamber facility at Lockheed Martin (LM), which is based on successful technology development at the Ames Coronagraph Experiment (ACE) facility.