The mainframe was located at Marshall Space Flight Center in Huntsville, Alabama. The massive, 6-year-old 2094-s54 model has 54 main processors and 512 GB of memory. According to Wikipedia, S54 mainframes cost "millions of dollars" when new. NASA CIO Linda Cureton wrote in a blog post that the shutdown of the Z9 ends the "mainframe era" at NASA. She noted that mainframes still have their place in computing where it does not matter if "end-user interfaces are clunky and somewhat inflexible," when there is a need for a system that delivers "extremely reliable, secure transaction oriented business applications."
According to Cureton, NASA kept the Z9 operational for older applications that are now being phased out. NASA apparently has not developed mainframe application in some time, which made the mainframe a rather costly proposition. Cureton also noted that NASA an save some money by shutting down some software licenses that are tied to the system, which runs Red Hat Enterprise Linux 4 (RHEL4).
NASA's first IBM mainframe, a 360/91 Model, shipped to NASA in 1967.