The HSTS System


HSTS is a problem solving framework for developing integrated planning and scheduling applications. It synthesizes the representational assumptions of contemporary temporal planning frameworks with the structured resource modeling concepts underlying current scheduling frameworks. contemporary planning and scheduling frameworks. There are three distinguishing characteristics of the HSTS framework:

Results and Applications

HSTS has been developed and applied principally in the context of space-based observatory scheduling problems, under funding provided by NASA. The original application focus was development of executable, short-term observing schedules for the Hubble Space Telescope (HST). The observation scheduler for HST that was developed was shown to scale to the full problem, producing observation schedules complete with all necessary enabling activities such as instrument reconfiguration, telescope repointing, data communication, etc. in a time frame acceptable for actual application. Complementary results demonstrated the ability of multi-perspective scheduling techniques to produce better quality schedules, in terms of balancing conflicting mission objectives, than a variant of the short-term scheduling algorithm currently being used in HST mission operations. More recently, HSTS has been used to develop of scheduler for application to a second orbiting telescope, the Small Wave SubMillimeter Astronomy Satellite (SWAS), currently due to be launched in June 1995. In collaboration with the SWAS mission team, we are currently evaluating the developed scheduler on full scale reference problems.

Current Status of HSTS

Ongoing development of the HSTS platform has moved with Nicola Muscettola from CMU to NASA Ames Research Center. Nicola can be reached at At CMU, we have incorporated HSTS solution representation and management concepts into the design of DITOPS a configurable, mixed-initiative planning and scheduling system.

Jump to --> ICL Lab home page
Stephen F. Smith <>