Hera, the first planetary defense mission of the European Space Agency (ESA), is traveling towards the only asteroid whose orbit has been modified by human action, a destination that will reach around the last quarter of 2026 to scrutinize the consequences of that kinetic impact.
Hera took off in a SpaceX Falcon 9 from Cape Canaveral (Florida) at 10:52 local time (14:52 GMT), disappearing into the clouds 30 seconds after takeoff. The Goldstone station in California received the first signals about an hour and a quarter after takeoff and the telemetry clearly reached the ESA mission control center in Germany.
“Today we write a new page in space history,” said Ian Carnelli, director of the Hera mission. “It is a magnificent moment for ESA and for European industry. “I am very happy.”
In a press conference after the launch, Carnelli, excited, explained the busy morning before takeoff, with a lot of tension and even moments of doubt about whether to launch or not due to bad weather, but the sky cleared for a while, with favorable wind data. “It couldn’t be a better day.”
After the uncertainty created by the weather and the approach, in addition, of Hurricane Milton to Florida, Today’s launch has placed Hera on a direct exit trajectory away from Earth, beginning its two-year cruise phase.
A maneuver scheduled for next month will be followed by a Mars approach in March 2025, which will give the spacecraft additional speed for its rendezvous with the Didymos binary asteroid system.
During gravity assist to Mars, car-sized Hera It will also carry out a survey of the Martian moon Deimosdeploying its instruments for scientific use for the first time.
The ultimate goal of this mission will be to scrutinize the binary asteroid system, focusing especially on the smaller of the two bodies, called Dimorphos, 150 meters in diameter.. This, in September 2022, was hit by the NASA DART spacecraft, which managed to deviate its orbit – for half an hour.
Hera is, along with DART, a planetary defense mission and both are integrated into the AIDA (Asteroid Impact and Deflection Assessment) collaboration. With them, the two space agencies intend to demonstrate the technology capable of deflecting asteroids to protect the Earth from a possible impact.
There is already enough data on DART’s feat thanks to its camera and a small Italian satellite (LICIACube) that detached from the ship a few days before and obtained images of the plume of fragments ejected in the collision, in addition to the view of several telescopes. .
However, crucial information is missing to really understand what happened there and to fine-tune models for deflecting asteroids. Hera, in which some 100 European companies and institutes participated – in addition to the Japanese agency JAXA – will have to answer, for example, whether a crater was formed on Dimorphos or the collision globally deformed the asteroid.
“DART’s impact was like the first episode of a cosmic adventure: a spectacular flash seen across space that left scientists wondering: what happened next?”said Patrick Michel, principal investigator of Hera.
The size of a shoe box
That is why Hera, led by OHB System AG from Germany, and its two small satellites the size of a shoe box (cubesats) now begin this long journey. Loaded with 12 instruments – the guidance, navigation and control system has been led by the Spanish GMV -, it will be in the vicinity of these asteroids for six months.
Named in honor of the Greek goddess of marriage, the mission will precisely determine their size and mass – the latter essential to measuring the effectiveness of the diversion – and will analyze the composition of their surfaces, as well as their thermal characteristics.
It will also measure the structure of its interiors by means of a radar on board one of the two cubesats that will detach from the main probe, and the gravitational field of the system with the help of a gravimeter made by the Spanish company EMXYs and the Royal Observatory from Belgium.
These cubesats are called Juventas, in Roman mythology the daughter of Hera, and Milani, in memory of the now deceased scientist Andrea Milani, who two decades ago contributed greatly to devising this mission that at that time seemed like science fiction and which bore the name of Don. Quixote -the two ships were called Hidalgo and Sancho-.
The first to separate very slowly from Hera – at 2 centimeters per second – will be Juventas and a week later Milani will do so, at the end of 2026 or beginning of 2027Franco Pérez, Spanish systems engineer at ESA and responsible for the two cubesats, told EFE.
The intention is for the mission to end with the ship and its two small satellites landing on one of the two asteroids.
bricks of the planets
Asteroids are the “bricks” with which the planets were formed when the Solar System developed and those that did not manage to stick to one of these bodies have traveled through space ever since. There are millions of them and they are centimeters, meters and even kilometers long, and more or less dangerous.
Some 36,000 are classified as NEOs – near-Earth objects – which implies that their orbits pass close, in astronomical terms, to the Earth’s orbit, according to data from ESA’s Near-Earth Object Monitoring Coordination Center (NEOCC). .
It is on these, due to their possible danger, that the focus is placed. The Didymos system is in this category.