The Hubble Space Telescope (HST) is a NASA/ESA funded project that was launched into orbit in 1990. The Space Telescope Science Institute (STScI) manages the solicitation/selection of science programs, planning and scheduling, and data archiving for HST.
HST Long Range Plan
HST's long range plan is approximately 18 months long and is updated nightly to ensure that it is kept current. All planning of the observations is done by HST staff for the investigators (ie., service mode observing). Observations are assigned a plan window which is usually about 2 months long, but can be smaller due to observing constraints. Plan windows can be discontinuous depending on the observation's constraints. The plan windows for all the observations may overlap with each other, so that at any point in time there is a pool of potential candidates available for the short term scheduling system.
The long range planning software supports astronomical event calculation (ie., sun, moon, orbital viewing, etc), both absolute (ie., do this observation at time x) and relative (ie., A after B by x days) timing constraints. Resource constraints (ie., Data Recorder Volume) are also modelled. There are numerous automatic planning algorithms available as well as the ability to manually plan observations. Below are some examples of the long range plan software's graphical user interface.
Our paper at the ADASS-97 conference describes the Spike long-range window planner in more detail.
HST Long Range Plan Window
HST Astronomical Event Plot Window
HST Plan Window Editor
HST Short Term Schedule
HST's Short Term schedules are 7 days in length and are created from the available pool of long range plan candidates whose plan window's overlap with the current scheduling period. Like the long range planning software, the short term scheduler supports astronomical event calculation, constraint modelling (absolute, relative, resource), and both manual and automatic scheduling. The output from the short term scheduler is an time ordered activity list (ie., slews, guide star acquisitions, on target time, etc.)