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.

Credit: MPS/GMV

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. 

Credit: GMV România

The images, the algorithm and the navigation system will tell Hera whether it is approaching or moving away from where it should be. "If the landmarks are moving away in a centrifugal movement, it means we are approaching the asteroid; if they are moving left or right we are moving away; if they are rotating that means Hera is rotating too."

When the mission gets very close to its target, there is a real danger that the space probes will collide with the target asteroid. Once more, the Romanians are responsible for avoiding such collisions.

Credit: ESA-Science Office

We are responsible for the safety of the mission

A team on the ground will see the same images and in parallel use the same algorithms developed in Romania, so they can compare the data with what is happening on board the satellite. "If there is a big difference between the two locations, something is wrong and the vehicle will go into safe mode," explains Iulian-Emil Juhasz.

In turn, the fault detection, isolation, and recovery (FDIR) system aims to identify if sensors are malfunctioning. For example, if the space equipment records data far outside the expected parameters, or if there are very large differences between two consecutive sets of data without other sensors confirming the situation, the system designed in Romania will identify the error and isolate that sensor so that its data are not passed on to the on-board computer.

Identified errors may even include collision danger with the asteroid. In this case, the command centre on Earth will guide Hera. In emergency situations, where communications cannot be fast enough, the mission goes on autopilot.

ESA – Science Office

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.

Credit: GMV România

Unique experimental system in Europe: 200-fold improvement in computing speed

In space missions, physical space is extremely precious. For the Hera mission to perform at its best, and to collect and process the data it receives, it needs extremely high computing power, for which it has very small components and low power availability. However, an innovation by the Romanian team will allow up to 200 times faster computing speed. Hera will be the first European mission to test this system, loaded on board as a payload.

Basically, the team has added an extra piece — a Field Programmable Gate Array (FPGA) — to take over some of the calculations. The result is similar to the presence of an extremely powerful processor that consumes less power and is 200 times more efficient. The system is fully developed, tested and flight-qualified by GMV Romania together with its partners.

In space, we work side by side with other European countries

Even though the Hera mission takes place in space, some of the benefits will be felt at home, in Romania. At the moment, there are only four countries that developed this image processing component for space: Spain, France, the UK and Greece. The component is essential in space missions, so the knowledge and know-how thus acquired will be useful in a wide portfolio of space activities: lunar missions, Mars missions, active means for space debris removal, orbital maintenance services, in-orbit assembly services.

In addition, Romania is strengthening its reputation in space research and development. "This is one of the few areas where we can say that we are working side by side with countries in Europe," thinks Cristian-Corneliu Chițu.  "The R&D side is appreciated as much as anywhere else in Europe."

In fact, advances in image processing, on which the Hera mission's navigation is based, can be replicated in other industries. "We take terrestrial technologies, improve them and then reintegrate them into commercial technologies on Earth. It's a spiral system through which we evolve." The developed technologies could be used in industries such as the automotive industry to improve autopilot performance. From a broader perspective, the technology can be useful in robotics development — for example, access to difficult areas such as mines, radiation zones or simply hard-to-reach areas. Optical processing also plays an important role in the autonomous movement of robots in warehouses through landmark recognition, or the development of robots working on assembly lines that need to be able to count, move objects or sort them according to colour or shape.

GMV currently has a team of 20 people working on the project, twice as many as when the project started. "We still have open positions and are constantly looking for experts and young graduates," says Cristian-Corneliu Chițu. Those interested can consult GMV's careers website by selecting Romania. Areas of interest are aircraft, aerospace engineering, electronics and telecommunications, science, mathematics-computing, artificial intelligence, geodesy, etc.

Main image credit: ESA - ScienceOffice.org