NASA to study ‘Earth-sized electric generator’

Illustration of NASA’s Ionospheric Connection Explorer, or ICON
Illustration of NASA’s Ionospheric Connection Explorer, or ICON. ICON explores Earth’s upper atmosphere and ionosphere, a region influenced by both terrestrial weather and changes in near-Earth space. (Image: NASA's Goddard Space Flight Center Conceptual Image Lab)

Two sounding rockets will be launched this month under NASA’s Dynamo-2 mission to team up with a satellite to study the giant electric current in Earth’s ionosphere. The two rockets, to be launched on separate days, will team up with NASA’s Ionospheric Connection Explorer (ICON) satellite to advance our understanding of the atmospheric dynamo, said the US space agency.

Some 50 miles up, where Earth’s atmosphere blends into space, the air itself hums with an electric current. Scientists call it the atmospheric dynamo, an Earth-sized electric generator. It’s taken hundreds of years for scientists to lay the groundwork to understand it, but the principles that keep it running are only just now being revealed in detail.

While most measurements of the dynamo come from magnetometers, a device on the ground that monitors the way current disturbs Earth’s magnetic field, taking measurements from inside the ionosphere will provide more detail about the phenomenon. Earth’s ionosphere is the dynamic region high in the atmosphere where terrestrial weather from below meets space weather from above.

Related article: China building solar power station in space

Scott England, a space physicist at Virginia Tech in Blacksburg and collaborator for the upcoming Dynamo-2 campaign, said the measure from inside the ionosphere is a “really tricky part” because the air is much too thin for an aircraft and too dense to fly most spacecraft.

“So one way of making these measurements is to fly a rocket through it,” England added.

One sounding rocket will launch into “quiet” conditions, while the other will launch into “disturbed” conditions, on two separate days. The launches will be timed so that the ICON satellite, designed to investigate changes in the ionosphere of Earth, will be passing over at the same time to compare data.

The sounding rockets will make brief measurements in space before falling back to Earth a few minutes later.

“While ground-based methods can provide large-scale, integrated measurements, sounding rockets give us local, fine-scale data on the ionospheric current,” said Takumi Abe, a space physicist at JAXA and collaborator for the Dynamo missions.

The Dynamo-2 rockets will launch from Nasa’s Wallops Flight Facility on Wallops Island, Virginia on separate days between July 6-20.

Read more about the mission here.