The selected proposals are:
- Coronal Physics Explorer (CPEX), Principal Investigator Dennis G. Socker, Naval Research Laboratory, Washington – CPEX will use a solar coronograph to study the processes responsible for accelerating the solar wind and generating the coronal mass ejections that can impact the Earth
- Gravity and Extreme Magnetism SMEX (GEMS), Principal Investigator Jean H. Swank, NASA’s Goddard Space Flight Center, Greenbelt, Maryland – GEMS will use an X-ray telescope to track the flow of highly magnetized matter into supermassive black holes
- Interface Region Imaging Spectrograph (IRIS), Principal Investigator Alan M. Title, Lockheed Martin Space Systems Co., Palo Alto, Calif. – IRIS will use a solar telescope and spectrograph to reveal the dynamics of the solar chromosphere and transition region
- Joint Astrophysics Nascent Universe Satellite (JANUS), Principal Investigator Peter W.A. Roming, Pennsylvania State University, University Park – JANUS will use a gamma-ray burst monitor to point its infrared telescope at the most distant galaxies to measure the star-formation history of the universe
- Neutral Ion Coupling Explorer (NICE), Principal Investigator Stephen B. Mende, University of California, Berkeley – NICE will use a suite of remote sensing and in situ instruments to discover how winds and the composition of the upper atmosphere drive the electrical fields and chemical reactions that control the Earth’s ionosphere
- Transiting Exoplanet Survey Satellite (TESS), Principal Investigator George R. Ricker, Massachusetts Institute of Technology, Cambridge – TESS will use a bank of six telescopes to observe the brightest 2.5 million stars and discover more than 1,000 Earth-to-Jupiter-sized planets around them.
NASA also received 17 Mission of Opportunity proposals for consideration and will schedule an evaluation board at a later date.
The proposals are vying to be the 12th and 13th Small Explorer missions selected for full development. The Explorer program is designed to provide frequent, low-cost access to space for heliophysics and astrophysics missions with small to mid-sized spacecraft. The program is managed by Goddard Space Flight Center for NASA‘s Science Mission Directorate.
Select this link for more information about the Explorer Program



