NASA Announces Small Explorer (SMEX) Selections

Paul Hertz, NASA Headquarters

NASA has made selections in the Explorer Program from proposals submitted in response to a recent Announcement of Opportunity for Small Explorers (SMEX) and Missions of Opportunity. Seven SMEX proposals and one Mission of Opportunity proposal were selected for concept studies, and one Mission of Opportunity proposal was selected for flight.

The seven SMEX's selected for study are:

• The Heavy Nuclei Explorer (HNX), a space laboratory that would determine the properties of the high energy atomic particles which are present in interstellar space. PI: Robert Binns of Washington University in St. Louis.
• The mission for Spectroscopy and Photometry of the Intergalactic Medium's Diffuse Radiation (SPIDR), a mission that would map the intergalactic "cosmic web" of hot gas which spans the Universe. PI: Supriya Chakrabarti of Boston University.
• The Satellite Test of the Equivalence Principle (STEP), a fundamental physics experiment to test the Equivalence Principle at an accuracy which is more than 100,000 times better than that achieved in laboratories on Earth. PI: Francis Everitt of Stanford University.
• Joule, an X-ray observatory that would obtain detailed energy spectra from extreme environments in the Universe ranging from the million degree coronae of nearby stars to the supermassive black holes at the cores of distant galaxies. PI: Richard Kelley of NASA's Goddard Space Flight Center.
• Aeronomy of Ice in the Mesosphere (AIM), a mission that would determine the causes of the highest altitude clouds in the earth's atmosphere. PI: James Russell III of Hampton University.
• The Jupiter Magnetospheric Explorer (JMEX), a mission that would study the magnetosphere of Jupiter by observing Jovian aurorae and the Io torus from Earth orbit. PI: Nicholas Schneider of the University of Colorado at Boulder.
• The Primordial Explorer (PRIME), an infrared observatory that would investigate the formation of the first quasars, galaxies, and clusters of galaxies. PI: Wei Zheng of the Johns Hopkins University.

• The Spectroscopy of Plasma Evolution from Astrophysical Radiation( SPEAR), an instrument that would trace the energy flow in the gas between stars when flown on the Korean KAISTSAT-4 mission. PI: Jerry Edelstein of the University of California at Berkeley.

• The Coupled Ion-Neutral Dynamics Investigations (CINDI), a mission to provide two instruments for the Air Force's Communication/Navigation Outage Forecast System (C/NOFS) satellite that will lead to a better understanding of the dynamics of the Earth's ionosphere. PI: Roderick Heelis of the University of Texas at Dallas.

The eight missions selected for study will begin a six month concept study in October 2001. After a thorough evaluation of the results of Phase A studies has been completed, NASA expects to select two SMEX missions for launch in 2004 and 2005. NASA may or may not select the Mission of Opportunity for flight. The mission already selected for flight will immediately begin a concept study which, after review, will be followed by definition, a confirmation review, and implementation.

Further information is available at http://spacescience.nasa.gov/codesr/smex/.

NASA Headquarters Responsible Office: Code SR
Last Updated: 13 September 2000
Author: Paul Hertz (Code SR)