Exoplanetary Circumstellar Environments and Disk Explorer(EXCEDE) is a proposed space telescope for NASA's Explorer program to observe circumstellar protoplanetary and debris discs and study planet formation around nearby stars of spectral classes M to B (within 100 parsec). The spacecraft will use a 70 centimeter diameter telescope-mounted coronagraph called PIAA (Phase Induced Amplitude Apodized Coronagraph) to suppress starlight in order to be able to detect fainter radiation of circumstellar dust. Characterizing constitution of such disks would provide clues for planetary formation (mostly in habitable zones), while already existing exoplanets can be detected through their interaction with dust disk. The project's principal investigator is Dr. Glenn Schneider.
Constrain giant planets' composition by measuring their reflectivity[3]EXCEDE will be the first to image (giant) exoplanets distances from their stars similar to ours (0.5-7 AU).[4]