The SMEX program NASA's Small Explorer program has selected new candidates for the SMEX-10 and SMEX-11 missions to be launched in 2006-7. Five candidates will be studied until late 2004, and then two will be chosen to fly. SMEX was started in the early 1990s amid concerns that all of NASA's science missions cost billions and took decades to complete. There have been 7 SMEX launches so far, with one more being built and other recently cancelled. Satellite Launch Orbit (km x km x deg) Mission SMEX-1/SAMPEX 1992 Jul 3 515 x 691 x 81.7 Earth radiation belts SMEX-2/FAST 1996 Aug 21 350 x 4169 x 83.0 Auroral studies SMEX-3/TRACE 1998 Apr 2 598 x 641 x 97.8 Solar EUV imager SMEX-4/SWAS 1998 Dec 6 634 x 699 x 70.0 Submillimeter astronomy SMEX-5/WIRE 1999 Mar 5 539 x 593 x 97.5 IR astronomy (failed) SMEX-6/HESSI 2002 Feb 5 588 x 609 x 38.0 Solar Hard X-ray imager SMEX-7/GALEX 2003 Apr 28 690 x 698 x 29.0 UV astronomical survey SMEX-8/SPIDR Cancelled SMEX-9/AIM 2006? 500 x 500 x 97? Noctilucent clouds The new candidates are: DUO Dark Universe Observatory DUO carries seven X-ray telescopes each with a 1.6m focal length, giving a wide 3 square degree field of view with 45-arcsecond spatial resolution (compare Chandra's ACIS with 0.5-arcsecond resolution but only 0.1 square degree field of view). DUO's CCD imagers, based on the EPIC-pn from XMM-Newton, will operate in the 0.3-10 keV range and scan 6000 square degrees around the North Galactic cap and is expected to discover 8000 clusters of galaxies and over 100000 active nuclei. The cluster data will be used to constrain cosmological models. (DUO is based on the German ABRIXAS mission, which would have done an all-sky survey, but whose power supply failed soon after launch). DUO is led by Richard Griffiths from CMU. IBEX Interstellar Boundary Explorer The IBEX mission is the only one of the proposals to study particles rather than photons, making use of the remarkable ENA (energetic neutral atom) imager technology previously pioneered in near-Earth space physics to map out the physics of the heliopause. The satellite will carry two ENA imagers, one for high energy and one for low energy particles, and will be boosted beyond the Earth's magnetosphere to allow it to detect and map out the distribution of energetic particles that are created in the shock region between the solar wind and the interstellar medium, and eventually reach the vicinity of the Earth. IBEX will be boosted by a Pegasus with an extra Star 27 solid motor fourth stage to a an orbit with an apogee of around 220000 km, and then use onboard propulsion to raise the perigee to 7000 km. If selected, it would be the first SMEX in high orbit. The mission is led by David McComas at Southwest Research Institute. NEXUS Normal Incidence EUV Spectrometer This NASA-Goddard mission will observe the solar corona and try to get clues to the coronal heating mechanisms. The normal incidence telescope, which has been flown on sounding rockets, allows better spatial resolution, allowing NEXUS to get the spectrum of the small flare regions on the Sun so spectacularly imaged by the earlier TRACE mission. PI is J. Davila. NuStar Nuclear Spectroscopic Telescope Array NuStar would be the first mission to fly a focussing telescope in space for energies in the 8-80 keV range. It will survey this energy band for X-ray emission from quasars and Galactic black hole binaries, and obtain spectra of hard X-ray emission from supernova remnants and study the spectral lines created by nuclear transitions which dominate this spectral range. The mission is led by Fiona Harrison (Caltech). JMEX Jupiter Magnetosphere Explorer The JMEX project would put an ultraviolet observatory in low Earth orbit, will all of its observing time dedicated to looking at Jupiter and its environment. Ultraviolet emission comes from Jupiter itself, its aurora, the moon Io, and the plasma torus in Io's orbit, and the study will characterize the dominant processes in the Jovian magnetosphere. The mission is led by N. Schneider at the University of Colorado.