2.2.2 spase://SMWG/Instrument/TWINS2/ENA TWINS-2 Energetic Neutral Atom (ENA) Imager TWINS-2 Neutral-atom Spectrometer TWINS-2 Wide-angle Imaging Neutral-atom Spectrometer 2012-03-10T02:14:09Z TWINS (Two Wide-angle Imaging Neutral-atom Spectrometers) is a Mission of Opportunity under NASA's Small Explorer (SMEX) program. TWINS-1 and TWINS-2 are the designations for NASA-sponsored instruments flying on unspecified non-NASA U.S. government spacecraft.The TWINS-1 instrument high voltages were turned on in April 2007 and the TWINS-2 high voltages in May 2008; the exact launchdates are not available. The data (including both science data and spacecraft ephemeris/attitude information) from the two NASA-funded science instruments are publicly available to the scientific research community. TWINS instrumentation includes an energetic neutral atom (ENA) imager to capture charge-exchange-produced neutral atoms over a broad energy range (approximately 1-100 keV) and a Lyman-alpha detector to measure the density of the neutral hydrogen geocorona needed for extraction of magnetospheric ion fluxes from neutral atom data. The TWINS-1 and TWINS-2 instruments are identical. spase://SMWG/Person/David.J.McComas PrincipalInvestigator TWINS Home Page http://twins.swri.edu ? spase://SMWG/Instrument/TWINS2/Imager Imager Energetic Neutral Atom Imager (ENA) on TWINS-2 spase://SMWG/Observatory/TWINS2