Two 2017 NASA missions set to study edge of space
Far above Earth’s tenuous upper atmosphere is a layer of charged particles that have been split into positive and negative ions by the Sun’s harsh ultraviolet radiation. This area where the Earth’s atmosphere and terrestrial weather give way to the space environment is called the ionosphere. In 2017, NASA plans to launch two satellite missions to study this region: the Ionospheric Connection Explorer (ICON) and the Global Observations of the Limb and Disk (GOLD).
“The ionosphere doesn’t only react to energy input by solar storms,” said Scott England, a space scientist at the University of California, Berkeley, who works on both the ICON and GOLD missions. “Terrestrial weather, like hurricanes and wind patterns, can shape the atmosphere and ionosphere, changing how they react to space weather.”
ICON will simultaneously measure the characteristics of charged particles in the ionosphere and neutral particles in the atmosphere to understand how they interact. GOLD will make many of the same measurements but from geostationary orbit, which will provide a global view of changes in the ionosphere.
Both missions will use a phenomenon called airglow, the light emitted by gas that is excited or ionized by solar radiation, to study the ionosphere. By measuring the light from airglow, researchers can track the changing composition, density, and temperature of particles in the ionosphere and neutral atmosphere.
ICON’s orbit 350 miles (about 563 kilometers) above Earth should allow the satellite to study the atmosphere in profile, giving researchers an unprecedented view of the state of the ionosphere at a range of altitudes. GOLD’s position 22,000 miles (approximately 35,406 kilometers) above Earth should enable it to track changes in the ionosphere as they move across the globe, the same way a weather satellite tracks a storm.
“We will be using these two missions together to understand how dynamic weather systems are reflected in the upper atmosphere, and how these changes impact the ionosphere,” said England.
England discussed the ICON and Gold missions, both Explorer-class missions managed out of NASA’s Goddard Space Flight Center in Maryland, during the recent fall meeting of the American Geophysical Union (AGU) in San Francisco.
UC Berkeley’s Space Sciences Laboratory is developing the ICON mission as well as the two ultraviolet imaging spectrographs. Meanwhile, the Naval Research Laboratory in Washington, D.C., will develop the MIGHTI instrument, and the University of Texas at Dallas will develop the Ion Velocity Meter.
The ICON spacecraft itself is being built by Dulles, Virginia-based Orbital ATK. The GOLD mission is led by the University of Central Florida, and the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder is building the instrument.
ICON is scheduled to launch in June of 2017 from the Reagan Test site on Kwajalein Atoll in the Republic of the Marshall Islands aboard a Pegasus XL launch vehicle from Orbital ATK’s “Stargazer” L-1011 aircraft.
Video courtesy of NASA
Jim Sharkey is a lab assistant, writer and general science enthusiast who grew up in Enid, Oklahoma, the hometown of Skylab and Shuttle astronaut Owen K. Garriott. As a young Star Trek fan he participated in the letter-writing campaign which resulted in the space shuttle prototype being named Enterprise. While his academic studies have ranged from psychology and archaeology to biology, he has never lost his passion for space exploration. Jim began blogging about science, science fiction and futurism in 2004. Jim resides in the San Francisco Bay area and has attended NASA Socials for the Mars Science Laboratory Curiosity rover landing and the NASA LADEE lunar orbiter launch.