A NASA mission launches this month to explore the zone between Earth's atmosphere and the lowest reaches of space, where key communications satellites orbit amid bright bands of color known as airglow.
Dubbed the GOLD mission -- for Global-scale Observations of the Limb and Disk -- it will be the first NASA science mission to fly an instrument on a commercial communications satellite when it launches January 25 from French Guiana, the agency said. More details about the mission were announced Thursday from the Goddard Space Flight Center in Greenbelt, Maryland.
The target area is home to communications satellites -- and colorful light bands
NASA also has named two finalists for future robotic missions far beyond Earth
The near-space environment is important because it's home to technology that is key to human communication, such as satellites that provide information for GPS systems and radio signals that help guide ships and airplanes.
It's also where astronauts live on the International Space Station.
The mission will examine the response of the upper atmosphere to forcing from the sun, the magnetosphere and the lower atmosphere. Learning more about the ionosphere, part of Earth's upper atmosphere where the sun's radiation collides with gas that breaks into electrons and ions, is key. This dynamic environment is always changing and could easily garble radio signals coming through our atmosphere. The mission will be able to see how exactly it affects our day-to-day life.
"GOLD will seek to understand what drives change in this region where terrestrial weather in the lower atmosphere interacts with the tumult of solar activity from above and Earth's magnetic field," NASA said in a statement. "Resulting data will improve forecasting models of space weather events that can impact life on Earth, as well as satellites and astronauts in space."
For years, scientists have been able to study Earth's upper atmosphere in detail, using ground-based observations as well as low-Earth-orbit missions. But they were missing the bigger picture.
The GOLD mission, situated in geostationary orbit over the Western Hemisphere, will take a global scan of the ionosphere and upper atmosphere every half-hour, allowing scientists to get a complete look at the temperature and weather of that region, which they've never had before. This continued observation has the capability to last for years.
Richard Eastes, principal investigator for the GOLD mission, said Thursday that the constant monitoring will allow for observations of other phenomena, such as the effects of solar flares.
The mission is also studying a relatively new area of scientific research. Previously, it was believed that the upper atmosphere was affected primarily by the sun's radiation, which creates space weather. But there is growing evidence that it's also affected by what's going on below, like the weather on Earth.
"Tsunamis create waves in the air, and they move upwards, which could cause changes at the boundary between Earth and space," said Sarah Jones, GOLD mission scientist. "GOLD is studying how to tease out effects of sun above and Earth below."
GOLD will work directly in concert with another mission launching this year: ICON, the Ionospheric Connection Explorer.
GOLD will capture the global perspective from 22,000 miles above Earth's surface, while ICON will capture a closer view from within the upper atmosphere itself, 350 miles above Earth. ICON can also directly measure particles and how they move.
This combined global and fine-scale view will provide scientists with unique perspectives and a more complete picture of "our interface to space."
Robot mission finalists announced
NASA also recently announced two finalist concepts for a robotic mission that will launch in the 2020s as part of the New Frontiers Program.
One, CAESAR, will return a sample from 67P/Churyumov-Gerasimenko, the comet that was explored by the European Space Agency's Rosetta spacecraft. Another, Dragonfly, will use a drone-like rotorcraft to explore sites on Saturn's largest moon, Titan.
There has been significant interest in that ocean world's chemistry and possible habitability, given that ocean worlds in our solar system may be suitable for some forms of life. One of these missions will be chosen in spring 2019.