Following the successful dynamic planning and implementation of IRAC Warm Instrument Characterization activities,
transition to Spitzer Warm Mission operations has gone smoothly. Operation teams procedures and processes required
minimal adaptation and the overall composition of the Mission Operation System retained the same functionality it had
during the Cryogenic Mission. While the warm mission scheduling has been simplified because all observations are
now being made with a single instrument, several other differences have increased the complexity. The bulk of the
observations executed to date have been from ten large Exploration Science programs that, combined, have more
complex constraints, more observing requests, and more exo-planet observations with durations of up to 145 hours.
Communication with the observatory is also becoming more challenging as the Spitzer DSN antenna allocations have
been reduced from two tracking passes per day to a single pass impacting both uplink and downlink activities. While
IRAC is now operating with only two channels, the data collection rate is roughly 60% of the four-channel rate leaving a
somewhat higher average volume collected between the less frequent passes. Also, the maximum downlink data rate is
decreasing as the distance to Spitzer increases requiring longer passes. Nevertheless, with well over 90% of the time
spent on science observations, efficiency has equaled or exceeded that achieved during the cryogenic mission.