Ariane 6 launch: Curie, NASA’s radio laboratory

CURIE, NASA’s CUbesat Radio Interferometer Experiment, is one of the payloads that will be launched during Ariane 6’s maiden flight, and CURIE will measure radio waves coming from the Sun and other radio sources in the sky. Such waves must be measured in space, because they are absorbed by the Earth’s ionosphere — a region 30 to 600 miles above the Earth’s surface made up of ionized (charged) gases that arise when solar radiation interacts with the upper atmosphere.

CURIE consists of two spacecraft that will be launched together as one, and then separate into two into orbit. Thanks to different observation points, the CURIE A and B satellites will be able to measure the same radio waves from two places at the same time. Using the technique of radio “interferometric analysis”, it is possible to reconstruct the origin of the detected radio waves.

The main scientific goal of CURIE is to use radio “interferometry” to study radio burst emissions from solar flares, such as flares and coronal mass ejections in the heliosphere. These events affect space weather, the effects of which are felt on Earth and other planets when they occur, increasing auroral activity and geomagnetic effects.

CURIE will be able to determine the location and size of the source regions of the radio bursts and track their outward movement from the Sun.

For a long time, such a space-based radio interferometry observatory, orbiting around the Earth or the Moon, or on the far side of the Moon, has been envisioned. The CURIE mission will be the first of its kind to measure radio waves from space in the frequency range between 0.1 and 19 MHz, and will serve as an experimental and pioneering platform for the development of new space-based radio observation techniques that are important for our understanding of the space weather environment of the heliosphere and the Sun’s influence on the planets of the Solar System.

In addition to its important scientific goals, CURIE will also demonstrate that the concept of a dedicated space interferometer can be achieved using relatively inexpensive CubeSats.

Ariane 6 is scheduled to be launched in June and July 2024. This comes after the great success of Ariane 5, the leading European rocket for more than a quarter of a century, which flew 117 times between 1996 and 2023 from the European Spaceport in French Guiana.

Ariane 6 is designed for all possible futures. The main advantage is maximum versatility. It can carry any satellite or payload to any orbit. This is made possible by a new restartable Vinci engine that will power the Ariane 6 upper stage multiple times, stopping and starting to take each mission to any orbit. It will provide enough fuel for a final deorbit burn and return safely through Earth’s atmosphere, or return the orbit to a nearby “graveyard orbit.”

Curie will be launched into a circular near-Earth orbit, 580 kilometers above the Earth’s surface and outside our planet’s radio-absorbing ionosphere.

“When we got a seat on the maiden flight of Ariane 6, the CURIE team was very excited,” says David Sundqvist, the mission’s principal investigator. “It is an important event in the world of navigation and space exploration.”

“For a team developing a new concept – a satellite radio interferometer that flies in formation – the launch on the maiden flight of the new Europa rocket is a satellite developer’s dream come true.”