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| [PHOTO: JD Hancock/Flickr/CC BY 2.0] |
Washington: NASA's Astrophysics Explorer Program has selected two
missions for launch in 2017: a planet-hunting satellite and an International
Space Station instrument to observe X-rays from stars.
The Transiting
Exoplanet Survey Satellite (TESS) and Neutron Star Interior Composition
Explorer (NICER) were among four concept studies submitted in September 2012.
NASA determined these two offer the best scientific value and most feasible
development plans.
TESS will use an
array of telescopes to perform an all-sky survey to discover transiting
exoplanets ranging from Earth-sized to gas giants, in orbit around the nearest
and brightest stars in the sky. Its goal is to identify terrestrial planets in
the habitable zones of nearby stars. Its principal investigator is George
Ricker of the Massachusetts Institute of Technology in Cambridge.
NICER will be mounted
on the space station and measure the variability of cosmic X-ray sources, a
process called X-ray timing, to explore the exotic states of matter within
neutron stars and reveal their interior and surface compositions. The principal
investigator is Keith Gendreau of NASA's Goddard Space Flight Center in
Greenbelt, Md.
"The Explorer
Program has a long and stellar history of deploying truly innovative missions
to study some of the most exciting questions in space science," said John
Grunsfeld, NASA's associate administrator for science in Washington. "With
these missions we will learn about the most extreme states of matter by
studying neutron stars and we will identify many nearby star systems with rocky
planets in the habitable zone for further study by telescopes such as the James
Webb Space Telescope."
NASA's Explorer
program is the agency's oldest continuous program and is designed to provide
frequent, low-cost access to space using principal investigator-led space
science investigations relevant to the Science Mission Directorate’s
astrophysics and heliophysics programs. Satellite mission costs are capped at
$200 million and space station mission costs are capped at $55 million.
The program has
launched more than 90 missions. It began in 1958 with the Explorer 1, which
discovered the Earth’s radiation belts. Another Explorer mission, the Cosmic
Background Explorer, led to a Nobel prize. NASA's Goddard Space Flight Center
manages the program for the agency's Science Mission Directorate in Washington.