NASA’s ICON mission ends with several ionospheric breakthroughs

After contributing to many necessary findings on the boundary between Earth’s ambiance and space, the Ionospheric Connection Explorer (ICON) mission has come to an finish. ICON launched in October 2019 and after finishing its two-year mission goals in December 2021, it operated as an prolonged mission for one more 12 months.

“The ICON mission has actually lived as much as its identify,” stated Joseph Westlake, heliophysics division director at NASA Headquarters in Washington. “ICON not solely efficiently accomplished and exceeded its main mission goals, it additionally offered crucial insights into the ionosphere and the interaction between space and terrestrial climate.”

The ICON spacecraft studied part of our planet’s outermost layer of the ambiance, known as the ionosphere. From there, ICON investigated what occasions influence the ionosphere, together with Earth’s climate from under and space climate from above.

The ionosphere is the bottom boundary of space, positioned between 55 miles to 360 miles above Earth’s floor. It’s made up of a sea of particles which have been ionized, a mixture of positively charged ions and negatively charged electrons known as plasma. This frontier of space is a dynamic and busy area, dwelling to many satellites—together with the Worldwide Area Station—and is a conduit for radio communications and GPS indicators.

Each satellites and indicators may be disrupted by the advanced interactions of terrestrial and space climate. Finding out and understanding the ionosphere is essential to understanding space climate and its results on our know-how.

The ICON mission captured unprecedented knowledge in regards to the ionosphere with direct measurements of the charged fuel in its rapid environment alongside photographs of one of many ionosphere’s most beautiful options—airglow.

ICON tracked the colourful bands as they moved by means of the ionosphere. Airglow is created by a process similar to what creates the aurora. Nevertheless, airglow happens world wide, not simply the northern and southern latitudes the place auroras are sometimes discovered. Though airglow is often dim, ICON’s devices have been specifically designed to seize even the faintest glow to construct an image of the ionosphere’s density, composition, and construction.

Via the precept of Doppler shift, ICON’s delicate imagers additionally detected the movement of the ambiance because it glowed. “It is like measuring a prepare’s pace by detecting the change within the pitch of its horn—however with gentle,” stated Thomas J. Immel, ICON mission lead on the College of California, Berkeley. The mission was particularly designed to carry out this technically tough measurement.

A brand new ionospheric perspective

The ICON mission’s complete view of the upper atmosphere offered useful knowledge for scientists to unravel for years to come back. As an illustration, its measurements confirmed how the 2022 Hunga Tonga-Hunga Ha’apai volcanic eruption disrupted electrical currents within the ionosphere.

“ICON was in a position to seize the pace of the volcanic eruption, permitting us to straight see the way it affected the movement of charged particles within the ionosphere,” Immel stated. “This was a transparent instance of the connection between tropical climate and ionospheric construction. ICON confirmed us how issues that occur in terrestrial climate have a direct correlation with occasions in space.”

One other scientific breakthrough was ICON’s measurements of the movement of ions within the ambiance and their relationship with Earth’s magnetic subject traces. “It was actually distinctive,” Immel remarked. “ICON’s measurements of the movement of ions within the ambiance was scientifically transformational in our understanding of conduct within the ionosphere.”

With ICON’s assist, scientists higher perceive how these interactions drive a course of known as the ionospheric dynamo. The dynamo, which lies on the backside of the ionosphere, remained a thriller for many years as a result of it’s tough to watch.

ICON offered the primary concrete remark of winds fueling the dynamo and the way this influences space climate. Unpredictable terrestrial winds transfer plasma across the ionosphere, sending the charged particles capturing out into space or plummeting towards Earth. This electrically charged tug-of-war between the ionosphere and Earth’s electromagnetic fields acts as a generator, creating advanced electrical and magnetic fields that may have an effect on each know-how and the ionosphere itself.

“Nobody had ever seen this earlier than,” Immel stated. “ICON lastly and conclusively offered experimental affirmation of the wind dynamo concept.”

An iconic legacy

On Nov. 25, 2022, the ICON crew lost contact with the spacecraft. Communication with the spacecraft couldn’t be established, even after performing an influence cycle reset utilizing a built-in command loss timer. Although the spacecraft stays intact, different troubleshooting strategies have been unable to re-establish contact between the ICON spacecraft and mission operators.

“ICON’s legacy will reside on by means of the breakthrough information it offered whereas it was energetic and the huge dataset from its observations that may proceed to yield new science,” Westlake stated. “ICON serves as a basis for brand new missions to come back.”