The Double Asteroid Redirection Test (DART): Overview and Investigations
Abstract
The Double Asteroid Redirection Test (DART) will be the first space experiment to demonstrate asteroid impact hazard mitigation by using a kinetic impactor. At this writing DART is currently in Preliminary Design Phase ("Phase B"), and is part of the Asteroid Impact and Deflection Assessment (AIDA), a joint ESA-NASA cooperative project. The mission is scheduled for its Preliminary Design Review in April 2018, with a transition to Final Design and Fabrication ("Phase C") afterward. The AIDA target is the near-Earth binary asteroid 65803 Didymos, an S-class system that will make a close approach to Earth in fall 2022. The DART spacecraft is designed to impact the Didymos secondary at 6 km/s and demonstrate the ability to modify its trajectory through momentum transfer. The primary goals of DART are (1) perform a full-scale demonstration of the spacecraft kinetic impact technique for deflection of an asteroid; (2) measure the resulting asteroid deflection, by targeting the secondary member of a binary NEO and measuring the resulting changes of the binary orbit; and (3) study hyper-velocity collision effects on an asteroid, validating models for momentum transfer in asteroid impacts. The DART Team has identified five broad "investigations" to be addressed by the project: Modeling and Simulation of Impact Outcomes, Remote Observations, Dynamical and Physical Properties, Science Proximity Operations, and Ejecta Dynamics and Evolution. The DART impact on the Didymos secondary will change the orbital period of the binary by at least 73 seconds, which can be measured by Earth-based optical and radar observations in the post-impact period. The baseline DART mission launches in 2021 to impact the Didymos secondary in 2022 near the time of its close pass of Earth, which enables an array of ground- and space-based observatories to participate in gathering data. The AIDA project will provide the first measurements of momentum transfer efficiency from hyper-velocity kinetic impact at full scale on an asteroid, where the impact conditions of the projectile are known, and physical properties of the target asteroid are also characterized. The DART kinetic impact is predicted to make a crater of order 10 meters diameter, depending on target physical properties, but will also release a large volume of particulate ejecta that may be directly observable from Earth or even resolvable as a coma or an ejecta tail by ground-based telescopes.We will discuss the plans for the DART mission and its investigations.
- Publication:
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42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E2864R