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Planetary Defense Part 2 - AIDA Double Mission

DART probe with the Dimorphos asteroid.

Images Credits: ESA/ ScienceOffice.org

The Asteroid Impact Deflection Assessment (AIDA) double-mission is an international cooperation effort to protect Earth from dangerous asteroids. The first of the two missions to take part will be NASA’s Double Asteroid Redirection Test (DART), followed by ESA’s mission Hera.  

DART was developed by NASA’s Planetary Defense Coordination Office together with Johns Hopkins Applied Physics Laboratory (APL). DART’s goal, as the name already says, is to demonstrate a technique to deflect asteroids. DART will depart Earth in 2021, and it will perform a kinetic impact into the double asteroid Dimorphos to deflect its orbit by collision, in September/ October 2022.

Orbiting Dimorpho’s 780 m-diameter mountain-sized main body (Didymos) is a smaller moon asteroid (160 m, about the same size as the Great Pyramid of Giza), Didymoon. The second will be intentionally crashed by the spacecraft at an approximated 24.000 km/h speed.  

Even though the Near-Earth asteroid isn’t a threat to Earth, Didymos is still a potentially hazardous asteroid. Changing it is orbit could have dangerous consequences, changing Didymoon’s orbit won’t redirect the main body. The fact of the asteroid is binary is what makes high precision measures possible. 

Because the asteroids are always moving, it makes it more challenging for both DART and HERA, considering that they need to be approached while the spacecraft can still communicate with Earth. The mission can be affected by asteroids’ composition, strength, structure, the amount of material ejected by the impact, and the angle at which the spacecraft comes.  

The spacecraft will release a shoebox-sized camera made by the Italian Space Agency. The camera will watch the event, take pictures from the debris, and maybe from the crater resulting from the impacts. The ground observatories also will be watching it (from a minimum distance of 10 million km).   

Hera Mission

Images Credits: ESA/ ScienceOffice.org

DART is an attempt to test the kinetic technique efficiency, which may save the world in the future. However, dust cloud formation will impact altered orbit measurements. It is expected a 10% uncertainty of the actual momentum, and information such as the mass Dimorphos and its crater shape will also be missed.  

Following up DART will be ESA’s mission named after the Greek goddess of marriage, Hera. ESA’s mission will conduct a detailed post-impact investigation, turning the experiment into a well-understood and repeatable deflection technique. It will gather vital scientific data to help scientists and mission planners understand better asteroids’ compositions, structure, and response to kinetic impacts.  

Hera is an optimization of ESA’s Asteroid Impact Mission (AIM), result from Space19+. The spacecraft will carry two CubeSats, named after Hera’s daughter, Juventas. The CubeSats will autonomously perform the first radar investigation of an asteroid’s interior, try out inter-satellite link technology in deep space, and provide ultra-low gravity operations experience.  

To demonstrate multiple technologies, including autonomous navigation around the asteroid, besides Juventas, Hera counts with several onboard payloads, including various optical cameras to take precise pictures of craters and investigate DART’s impact. It will use high-resolution visual, laser, and radio science to detailed map Didymoon’s surface and interior structure. Hera will also measure Didymoon’s mass.  

  

Together, Dart and Hera missions will demonstrate if the asteroid defense method is valid or if other approaches are needed and how to make the best use of the technology available. It will also improve the understanding of asteroids’ compositions, which, together with a better understanding of deflection impacts, lead to a more effective way to protect our planet.

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This article was written by Juliane Verissímo - Marketing Department of VisionSpace