NASA have validated a mission aiming to construct a satellite to get an asteroid to deviate from its course. Although for the moment no such object has proven to be a threat, the American space agency want to see whether such a feat would be possible.
The Double Asteroid Redirection Test (DART) has been validated by NASA. The project involves constructing a half-ton satellite that will be launched in December 2020, to strike the smallest member of the Didymos pair of asteroids in 2022. The pair of asteroids is made up of Didymos A (measuring 780 m in diameter) and Didymos B, another fragment measuring 160 m in diameter, and orbiting around the first (see the model at the bottom of the article).
The goal? To try and modify the trajectory of Didymos B, by affecting its speed. NASA wants to see whether such an operation is feasible, just in case an asteroid were ever to really cross our planet’s path. Projecting a kinetic impactor onto the object was the chosen solution, selected from other options including towing, or the use of a nuclear warhead. The kinetic impactor option is the most advanced and the most easily workable solution.
While it will be the first large scale test of this kind of strategy, a probe should be sent to the area after the impact. Due to funding concerns, the ESA will carry out this mission using the HERA probe, which will reach Didymos in 2026. It will be too late to observe the impact, but the probe will however be able to observe Didymos B from every angle and evaluate the efficiency of the impactor.
It should be borne in mind that Didymos is considered an ideal target. Observed carefully since 2003, the binary asteroid appears to have the same composition as other asteroids. Furthermore, although the shape of Didymos A is well known, the shape of Didymos B isn’t. But what is for sure is that it is the ideal size for testing a kinetic impactor.