This XML schema file has been generated from the PDS4 Information Model. The Mission Information class provides a set of optional attributes that have their value sets defined by the mission. This section contains the simpleTypes that provide more constraints than those at the base data type level. The simpleTypes defined here build on the base data types. This is another component of the common dictionary and therefore falls within the pds namespace. The mission_phase_identifier attribute provides an identifier for a mission phase. The mission_phase_name attribute provides the commonly recognized name for a mission phase. The spacecraft_clock_start_count attribute provides the value of the spacecraft clock at the beginning of a time period of interest. The spacecraft_clock_stop_count attribute provides the value of the spacecraft clock at the end of a time period of interest. The start_orbit_number attribute provides the first in a series of numbers that represent a set of orbital revolutions of one body around another. The stop_orbit_number attribute provides the last in a series of numbers that represent s set of orbital revolutions of one body around another.