Highlights from HST/NICMOS Original Research Article

The near-infrared camera and multi-object spectrometer (NICMOS) was installed in the Hubble Space Telescope in February 1997. After 22 months of operation the 110 kg supply of solid N2, which cooled the NICMOS-3 HgCdTe detectors, was exhausted. The cryostat warmed up leaving the instrument in an electromechanically functional, but scientifically non-viable, passive state. Following a three year suspension of observations, an active cooling system featuring a reverse Brayton cycle micro-turbine was installed and integrated with NICMOS during HST servicing mission 3B. As a result the NICMOS detectors and cold optics have successfully been re-cooled to operationally effective temperatures and the science program has begun. We review the operating characteristics of the NICMOS instrument, its new cooling system, and its performance both in absolute terms and in comparison to its previous on-orbit incarnation. We discuss the scope and nature of the astronomical investigations that have been and are again enabled with NICMOS. Additionally, we present some of the first scientific results from programs executed with the re-cooled NICMOS.