... Distributed Object Controller (DOC) - A system which handles messages passing between distributed processes to be used as a controller for both RPS2 and the HST operational flow. RPS2 Toolkit - The specialization of the DOC which allows it to control RPS2 process flow. ... Exposure Time Calculators (ETCs) to simulate data collection for various instruments. ... It allows roll and pointing constraints to be specified and connects to several publicly available target catalogs for target data. ...