What will happen to humanity if an asteroid hits Earth again? Will we suffer the same fate as the dinosaurs or will we be able to avoid disaster? This year sees the first international effort to deflect an asteroid’s trajectory, and Romania is one of the countries contributing to the European component of the mission.
65803 Didymos is an asteroid classified as potentially hazardous, consisting of the main asteroid and its satellite, called Dimorphos. 65803 Didymos is the target of the international AIDA (Asteroid Impact and Deflection Assessment) mission, with its two components: the American DART component that will impact the asteroid’s satellite on 26 September 2022, and the European Hera component that will observe whether or not we have successfully deflected the asteroid.
Romania will provide some key elements for the success of the European mission. The Romanian expertise will help Hera to reach the asteroid and measure its deflection very precisely, following the impact with DART. It will also support one of ESA’s first two deepspace cubesats to approach the asteroid.
In this article we explore the components made in Romania that will be the ‘eyes’ of the Hera mission, without which it would not be able to guide and manoeuvre itself properly.
Basically, everything the mission satellite will see, as well as the way the data is interpreted to guide it to its destination, will depend on Romanian technology, which GMV Romania experts are currently working on. Part of an international consortium, GMV’s Romanian subsidiary will be responsible for image processing, altitude-based guidance, error identification and isolation and the image-processing-based navigation of Hera’s main satellite, as well as of a smaller probe that will get closer to the asteroid, Juventas — one of the European Space Agency’s (ESA) first two deepspace cubesats.
Why deflect an asteroid?
NASA’s DART mission is heading towards two asteroids that form the Didymos binary system. NASA’s spacecraft will intentionally collide with the smaller of the two asteroids on 26 September 2022 to see if it can alter its orbit.
ESA will then send its own mission to the two asteroids to observe in detail what happened after the impact. The Hera mission will measure the asteroid’s mass and composition, analyse the crater caused by the collision and help us better understand the asteroids. In addition to the main satellite, Hera will also have two smaller probes, Juventas and Milani, which will get much closer to the asteroid, to collect scientific data and then land on it.
This information is essential if we are to defend our planet from the threat posed by asteroids. “To solve a problem effectively, you first need to know it very well,” explains Cristian-Corneliu Chițu, Director of Space at GMV Romania.
So far, the scientific community has incomplete information about the asteroids, and the mission is based on theoretical knowledge, which has not yet been validated. “We want to know what the asteroid is made of, whether the surface is metallic or covered with ice, whether it heats up or not, how it reacts when the asteroid enters the shadow, what information the infrared images will give us.” All this data helps us better understand asteroids.
Hera will also measure whether or not the deflection attempt was successful. “We’ll see how far the satellite asteroid will have moved relative to the centre of the binary system and how the trajectory will have changed.”
Based on the information gathered, humankind will know how to better manage risky situations involving asteroids. “In the future we will know how big the impact should be and where we should hit an asteroid. At the same time, we will learn what kind of resources are found on asteroids and whether we can use them for the benefit of humanity,” added Iulian-Emil Juhasz, Head of Space Segment and Robotics, GMV Romania.
Hera has Romanian eyes
To reach the binary asteroid Didymos safely, the Hera mission will be guided by a system designed in Romania. GMV is developing a guidance and navigation system (GNS) based on data analysis from the mission’s cameras and sensors. Using algorithms designed in Romania, teams on the ground will know whether the spacecraft is still heading towards the asteroid or has deviated from the established trajectory.
If the spacecraft needs to readjust its trajectory, the commands received will be ‘translated’ into a signal that the vehicle can interpret and execute also using GMV technology.
Hera’s journey to the asteroid will take more than two years, and the landscape will change several times along the way, so the mission’s guidance will need to be different along the way. “At first, the asteroid will be so far away that there will be only one pixel on the mission camera, gradually turning into a cluster of pixels. During this phase, the GNS system will rely on keeping the asteroid in the camera’s field of view so that the mission is always aimed at that point,” says Iulian-Emil Juhasz.
As Hera approaches the asteroid, the guidance system must take other factors into account, constantly calculating where the centre of the asteroid is and how it is moving.
When the mission gets close to its target, the asteroid will cover the whole image, so the mission will have to switch to a different type of navigation. “In this case, we need to detect landmarks on the asteroid, such as boulders, craters or ridges, anything that has a clear shadow. This way, we can understand where the mission is in relation to the asteroid,” continues Iulian-Emil Juhasz.
The Juventas satellite is partly built in Romania
Romanian innovation will also be present on the Hera mission’s payload, Juventas, which is extremely important for better understanding asteroids. This is a small satellite — a CubeSat — that will be launched from the main spacecraft and reach the target asteroid for close study.
Once in orbit around its target body, Juventas will open an antenna larger than its size to carry out the first underground radar survey of an asteroid. The radar signals should reach a depth of 100 metres, providing information about the asteroid’s internal structure. During the flight, Juventas will also gather information about the asteroid’s gravitational field, and will eventually land on the asteroid if the conditions allow it. This last step will provide information about the impact force, rebound and surface of the asteroid.
All this will be possible thanks to the Romanian contribution. Juventas will use the same Romanian technology for guidance and navigation as Hera. Moreover, one third of Juventas is made in our country. “The Romanian team is responsible for defining the mission, choosing the operational orbits and planning the mission step by step, from the launch from Hera to the asteroid landing,” says Iulian-Emil Juhasz.