Intelligent Scheduling of Hubble Space Telescope Observations

This paper describes the S PIKE system, a general framework for scheduling which has been developed by the Space Telescope Science Institute for NASA’s Hubble Space Telescope (HST). Efficient use of astronomical observatories is very important to the scientific community: the demand for research-grade telescopes far exceeds the supply. The need for efficient scheduling is especially keen for space-based facilities due to their very high cost, limited numbers, and unique scientific potential. The S PIKE scheduler was developed for Hubble Space Telescope but was designed for generality and flexibility: it has since been adapted for several other astronomical scheduling problems, as well as to problems unrelated to astronomy. While the general approach taken in S PIKE was motivated by the paradigm of scheduling as constraint-directed search (e.g. Fox 1987, Smith et al. 1986, Fox et al. 1989), S PIKE incorporates novel approaches to both the quantitative representation and propagation of hard constraints and “soft” preferences, and to the use of scheduling search strategies based on multistart stochastic repair.