An international planetary defense mission involving NASA and ESA will now include two CubeSats. APEX and Juventas will use ESA's Hera spacecraft, which is due to arrive at the binary system of asteroids Didymos shortly after NASA's Double Asteroid Redirect Test (DART) impacted the smaller of the two objects, Didymoon . Hera will arrive to make observations of the consequences of DART as part of the international Asteroid Impact Deflection Assessment (AIDA) experiment.
DART and Hera were designed together as part of AIDA's goals. While parts of the mission have been refined over the years, mainly due to funding challenges, a key objective of the mission is to combine the DART and HERA missions for overall scientific and technological return, while protecting the element of international cooperation. Life scenario – currently reserved for Hollywood movies – asks for options to protect the planet from an asteroid attack.
Unlike the need to fly Bruce Willis and a team of deepwater drillers, the saviors of the planet will be robotic spaceships.
To test potential techniques to "deflect" an asteroid – one of the preferred methods to mitigate a threat – DART will travel to the binary system of Didymos asteroids through a xenon-based electric propulsion system with an integrated camera and sophisticated navigation software autonomous .
Upon arriving at Didymos – currently declared in October 2022 – it will head to Didymoon at a speed of approximately 6 km / s. The last thing DART will transmit back to Earth before the collision will be a close-up of Didymoon's surface features.
The collision will change the speed of the moonlet in its orbit around the main body by a fraction of a percent, enough to be measured using telescopes on Earth. However, Hera will get a closer look when she arrives a few years later.
Hera – in honor of the Greek goddess of marriage – is the European contribution to an international dual-spacecraft mission, accompanying the DART with detailed post-impact research that will transform this experiment on a grand scale into a well-understood and repeatable planetary defense. technique.
In doing so, Hera will also demonstrate several new technologies, such as autonomous navigation around the asteroid – like modern unmanned cars on Earth, and will gather crucial scientific data to help scientists and future mission planners better understand compositions and structures of asteroids .
Due to the launch in 2023, Hera will travel to the pair of Earth-bound asteroids. The main body the size of a mountain 780 m in diameter is orbited by a moon of 160 m, informally called Didymoon, approximately the same size as the Great Pyramid of Giza.
Although the mission still requires a final green light from the Agency's Council of Ministers at European level in late 2019, ESA announced that Hera will transport two tiny CubeSats to be used – and possibly landing – on the asteroids of Didymos. The announcement comes after the Hera mission received proposals for CubeSats from across Europe, and an evaluation committee made the final selection.
CubeSats has become one of the unexpected stars of NASA's recent landing on Mars with InSight Lander. The two MarCO CubeSats performed admirably, delivering crucial information as InSight conducted its successful EDL (Entry, Descent and Landing).
"The idea of building CubeSats for deep space is relatively new, but it was recently validated by NASA's InSight that landed on Mars last November when a pair of companion CubeSats was able to transmit Lander's radio signals back to Earth – as well such as returning images of the Red Planet, "said Paolo Martino, chief engineer of the Hera spacecraft.
The first CubeSat companion is called the Asteroid Prospecting Explorer (or "APEX") and was developed by a Swedish / Finnish / Czech / German consortium.
He will perform detailed spectral measurements of the surfaces of both asteroids – measuring the sunlight reflected by Didymos and breaking their various colors to find out how these asteroids interacted with the space environment, identifying any differences in composition between the two. In addition, APEX will do magnetic readings that will provide information about the internal structure of these bodies.
Guided by a navigation camera and a laser instrument – (laser guide), APEX will also make a landing on one of the asteroids, gathering valuable data in the process using inertial sensors, and making close-up observations of asteroids. surface material.
In orbit next to Didymoon, Juventas will line up with Hera to conduct satellite-satellite radio-science experiments and conduct a low-frequency radar survey inside the asteroid, similar to performing a detailed "x-ray scan" of Didymoon. to unravel its interior.
Hera is scheduled to be launched on the upcoming Ariane 6 mission, one of the first scientific missions to use the new Arianespace rocket. The mission will end with a landing, using the dynamics of any likely jump to capture details of the asteroid's surface material – followed by several days of surface operations.
Hera is set to be humanity's first mission for a binary system of asteroids. In addition to testing deep space technologies and collecting crucial scientific data, Hera was designed to be Europe's contribution to an international planetary defense effort: it would examine the crater and measure Didymoon's orbital deviation caused by the previous collision of a NASA probe, called DART.
This unique experiment will validate the asteroid deflection technique known as kinetic impactor, allowing mankind to protect our planet from the impacts of asteroids.
"We are very happy to have these high quality CubeSat missions joining us to perform the additional bonus science next to their mother ship Hera," explains Hera manager Ian Carnelli.
"By loading additional instruments and venturing us much closer to our target bodies, they will give different perspectives and further investigations on this exotic binary asteroid. They will also give us valuable experience of proximity operations transmitted by the Hera motherboard in extreme low-gravity conditions. This will be very valuable for many future missions. "