Yesterday, ESA’s Hera space probe blasted off atop a SpaceX Falcon 9 rocket from Cape Canaveral together with the two nanosatellites Juventas and Milani. After about 76 minutes, it successfully separated from the rocket’s last stage and set on its course which in almost exactly two years will take it to the asteroid Didymos and its moon Dimorphos to examine the consequences of the impact of NASA’s DART spacecraft.
The DART mission, with its impact on the asteroid Dimorphos on September 26, 2022, was an important phase in a project to defend the Earth from dangerous asteroids. After that impact, several telescopes were used to monitor the consequences, in particular how much the trajectory of Dimorphos changed, which was the purpose of the DART mission.
Precise information requires a survey from the vicinity, which will be conducted by the Hera spacecraft and the nanosatellites Juventas, named after the goddess Hera’s daughter, and Milani, named after astronomer Andrea Milani Comparetti, who proposed the original mission from which the DART and Hera missions were derived.
The Hera space probe is equipped with a series of instruments with which it will accurately detect the trajectory of the asteroid Dimorphos and capture close-up images of it, examine its composition and that of the surrounding dust. Remote observations already indicated that the impact of the DART spacecraft generated a lot of debris with the possibility that some of it will reach the Earth. Hera will also be able to examine that debris in detail.
The two nanosatellites traveling with the Hera space probe are of the CubeSat class and are composed of 6 cubic units each. Juventas and Milani are equipped with some instruments that will enable them to conduct various types of surveys complementary to that of Hera, which will act as a radio relay for their communications. Their mission will provide new valuable information to understand how to divert an asteroid that is dangerous for life on Earth.
The Hera space probe and the two nanosatellites Juventas and Milani have begun their two-year journey into deep space. SpaceX received special permission for this launch after a problem with the Falcon 9 rocket’s second stage grounded the flights because this mission was launched out of orbit, meaning the second stage did not re-enter to disintegrate on the descent into the atmosphere. For once, the first stage didn’t land because all the propellant was used to boost Hera and was lost after 23 launches.
