Index of content:
Volume 78, Issue 1, January 2007
The National Aeronautics and Space Administration’s Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991–2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer’s expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.
- GRAVITY; GEOPHYSICS; ASTRONOMY AND ASTROPHYSICS
78(2007); http://dx.doi.org/10.1063/1.2431089View Description Hide Description
A new instrument to analyze the chemical composition of dust particlesin situ in space has been developed. The large target area makes this instrument well suited for detecting a statistically significant number of interstellar dust grains or other dust particles with a low flux. The device is a reflectron-type time-of-flight mass spectrometer that uses only flat electrodes for the generation of the parabolic potential. The instrument analyzes the ions from the impact generated plasma due to hypervelocity dustimpacts onto a solid target surface. The SIMION ion optics software package is used to investigate different potential field configurations and optimize the mass resolution and focusing of the ions. The cylindrically symmetric instrument operates with six ring electrodes and six annular electrodes biased to different potentials to create the potential distribution of the reflectron. The laboratory model of the instrument has been fabricated and tested. Hypervelocity dustimpacts are simulated by laser ablation using a frequency doubled Nd:YAG laser with pulse length. The experimental data show typical mass resolution .