NASA’s Planned ‘Ignorosphere’ Mission Could Improve Space Weather Predictions

There is a layer of the Earth’s atmosphere that scientists know very little about. Dubbed “the ignorosphere,” this layer on the periphery of space plays a huge role in determining the intensity of space weather events.

A new space mission is being prepared to try to shed light on the processes taking place there, but it won’t be ready until now. solar cycle ends.

When bursts of charged particles from the Sun who form the solar wind hits Earth, strange things are happening in the gas mantle of the planet. These heavy particles (protons, electrons and heavy ions) collide with atoms in the upper atmosphere, energizing them, Juha Pekka Luntama, head of space weather at the European Space Agency (ESA), told Space.com .

Related: Solar storms can easily destroy satellites – space weather expert explains the science

Most of this energy exchange occurs in the thermosphere, the second highest layer of earth’s atmosphere which ranges between altitudes of 60 miles to 360 miles (100 to 600 kilometers). The excess energy heats up the thermosphere and causes it to inflate. The density of the thin gases that fill this region of space increases. In turn, satellites in low Earth orbit face more drag and sometimes fall to Earth prematurely.

“It’s like running against the wind,” Anja Stromme, head of ESA’s Swarm mission, who recently experienced altitude hold problems because of the bad space weathertold Space.com.

Most of these changes occur in the lowest layer of the thermosphere at altitudes of 60 to 120 miles (100 to 200 km), just above the karman lineage, a widely recognized boundary between Earth’s atmosphere and outer space. Scientists sometimes refer to this region as the “ignorosphere”, due to the lack of data collected there.

“It’s too high for balloons but too low for satellites,” Stromme said.

Without these measurements, space weather forecasters have little way to improve their predictions of the changes occurring in this region in response to solar flares and other solar flares. They have no means of providing proper information to satellite operators whose spacecraft are in danger. In February of this year, SpaceX saw firsthand the seriousness of this risk when it lost 40 new Starlink satellites which fell victim to bad space weather just after launch.

“When we see an event on the sun, we can warn satellite operators to be careful and aware,” Luntama said. “But it is very difficult to predict exactly the magnitude of the impact and the increase in atmospheric drag from the satellites.”

NASA and ESA have plans for a satellite mission that would help fill these gaps. Operating such a mission, however, is quite a challenge, as it would run a very high risk of succumbing to the exact phenomenon it would be launched to study.

“The problem is that in this region, about 150 kilometers [90 miles] from Earth’s surface, there’s still too much atmosphere to slow down the satellites,” Luntama said. “If you were flying a mission there, it would only stay in orbit for a short time and then it would spin spiral through the atmosphere and burn up. “

The two space agencies want such a mission to remain in orbit for years so that it is exposed to space weather events of varying frequency and intensity. The frequency with which the sun produces sunspots, which are the source of solar flares and flares that affect the Earth, varies depending on the 11 year cycle of the sun of activity. To ensure that such a mission continues to provide information as the sun moves through this cycle, mission engineers must very carefully design the orbit of the spacecraft so that it only makes very brief dives into the low altitudes of the ignorosphere while following an elliptical trajectory.

“The perigee [the closest point to Earth] should be between 100 and 150 kilometers [60 and 90 miles] so we can get the measurements,” Luntama said. “The apogee [the farthest point from the planet] should be several hundred kilometers — 500 or 600 km [300 or 360 miles] – which is clearly removed from the atmosphere.”

The spacecraft would circle the planet roughly every 90 minutes, Luntama said, using an onboard propulsion system to compensate for loss of speed during flight through dense lowlands.

“We would like to measure charged particles [from the sun] but also the density of the atmosphere in that region,” Luntama said. “We also need information about the Earth’s magnetic field, because it changes during solar storms. And finally, we need precise information on how the atmosphere is slowing down the satellite.”

The mission, however, is still in the planning stages and will not enter the ignorosphere until the end of this solar cycle, Luntama added.

“We have established a science team made up of European and American scientists, and we are currently working on the definition of the mission,” Luntama said. “Once we have more precisely defined the mission objectives and the measurements we want, the engineering teams can then begin to consider how to build such a mission capable of doing so.

In the meantime, solar weather experts are doing what they can to improve their forecasts while the sun continues to exceed their earlier predictions, producing far more sunspots, solar flares, and flares than expected. After its first-hand encounter with the vagaries of space weather, SpaceX partnered with the U.S. National Oceanic and Atmospheric Administration (NOAA) and began providing baseline drag data. Stellar Link experience of satellites as they climb into orbit after launch, Tzu-Wei Fang, a NOAA space scientist, told Space.com in a previous interview.

NOAA uses this information to improve its Whole Atmosphere model, which attempts to predict space weather near Earth, much like meteorologists model weather on the planet.

Follow Tereza Pultarova on Twitter @TerezaPultarova. Follow us on Twitter @Spacedotcom and on Facebook.

Comments are closed.