The Spitzer Space Telescope is a cryogenically cooled telescope operating three instruments in wavelengths ranging from 3.6 microns to 160 microns. Spitzer, the last of NASA's Great Observatories, was launched in August 2003 and has been operating for 4.5 years of an expected 5.5 year cryogen mission. The highly efficient Observatory has provided NASA and the science community with unprecedented data on galaxies, star formation, interstellar medium, exoplanets, and other fundamental astronomical topics. Spitzer's helium lifetime is predicted to end on April 18, 2009, with an uncertainty of +/- 3 months. Planning for this cryogen end involves many diverse areas of the project and is complicated due to the uncertainty in the actual date of helium depletion. This paper will describe how the Spitzer team is accommodating the unknown end date in the areas of observation selection, planning and scheduling, spacecraft and instrument monitoring, data processing and archiving, and finally, budgeting and staffing. This work was performed at the California Institute of Technology under contract to the National Aeronautics and Space Administration.
Spitzer Space Telescope was launched on 25 August 2003 into an Earth-trailing solar orbit to acquire infrared observations from space. Development of the Mission Operations System (MOS) portion prior to launch was very different from planetary missions from the stand point that the MOS teams and Ground Data System had to be ready to support all aspects of the mission at launch (i.e., no cruise period for finalizing the implementation). For Spitzer, all mission-critical events post launch happen in hours or days rather than months or years, as is traditional with deep space missions.
At the end of 2000 the Project was dealt a major blow when the MOS had an unsuccessful Critical Design Review (CDR). The project made major changes at the beginning of 2001 in an effort to get the MOS (and Project) back on track. The result for the Spitzer Space Telescope was a successful launch of the observatory followed by an extremely successful In Orbit Checkout (IOC) and operations phase. This paper describes how the project was able to recover the MOS to a successful Delta (CDR) by mid 2001, and what changes in philosophies, experiences, and lessons learned followed. It describes how projects must invest early or else invest heavily later in the development phase to achieve a successful operations phase.
This paper explores the how's and why's of the Spitzer Mission Operations System's (MOS) success, efficiency, and affordability in comparison to other observatory-class missions. MOS exploits today's flight, ground, and operations capabilities, embraces automation, and balances both risk and cost. With operational efficiency as the primary goal, MOS maintains a strong control process by translating lessons learned into efficiency improvements, thereby enabling the MOS processes, teams, and procedures to rapidly evolve from concept (through thorough validation) into in-flight implementation. Operational teaming, planning, and execution are designed to enable re-use. Mission changes, unforeseen events, and continuous improvement have often times forced us to learn to fly anew. Collaborative spacecraft operations and remote science and instrument teams have become well integrated, and worked together to improve and optimize each human, machine, and software-system element. Adaptation to tighter spacecraft margins has facilitated continuous operational improvements via automated and autonomous software coupled with improved human analysis. Based upon what we now know and what we need to improve, adapt, or fix, the projected mission lifetime continues to grow - as does the opportunity for numerous scientific discoveries.
Spitzer Space Telescope, the fourth and final of NASA's Great Observatories, and the cornerstone to NASA's Origins
Program, launched on 25 August 2003 into an Earth-trailing solar orbit to acquire infrared observations from space.
Spitzer has an 85cm diameter beryllium telescope, which operates near absolute zero utilizing a liquid helium cryostat
for cooling the telescope. The helium cryostat though designed for a 2.5 year lifetime, through creative usage now has an
expected lifetime of 5.5 years. Spitzer has completed its in-orbit checkout/science verification phases and the first two
years of nominal operations becoming the first mission to execute astronomical observations from a solar orbit. Spitzer
was designed to probe and explore the universe in the infrared utilizing three state of the art detector arrays providing
imaging, photometry, and spectroscopy over the 3-160 micron wavelength range. Spitzer is achieving major advances in
the study of astrophysical phenomena across the expanses of our universe. Many technology areas critical to future
infrared missions have been successfully demonstrated by Spitzer. These demonstrated technologies include lightweight
cryogenic optics, sensitive detector arrays, and a high performance thermal system, combining radiation both passive and
active cryogenic cooling of the telescope in space following its warm launch. This paper provides an overview of the
Spitzer mission, telescope, cryostat, instruments, spacecraft, its orbit, operations and project management approach and
related lessons learned.