ESA's Hera mission for planetary defense will perform a close-up survey of the Dimorphos asteroid in deep space. But first Hera needs to cross millions of kilometers of space to get there. That is the task of Hera's Propulsion Module, forming around half of the overall spacecraft, which has been prepared by Italy's Avio company.

Formed of a central tube plus a supporting structure, the Module has been fitted with propellant tanks, piping and thrusters (inside the red protective covers). But before it can be joined to Hera's other element, the Core Module, this Propulsion Module had to undergo its crucial "global leak test"—as seen in this video.

The Module was filled with gaseous nitrogen, then placed inside its container. Sensors added to the interior can detect any pressure change inside the container over the course of the night. Success means Hera is ready to travel to OHB in Germany to be mated with the Core Module. At this point the Hera spacecraft will be complete, and the mission will come a major step nearer to space.

The amount of space debris has not stopped increasing since the first satellite was launched in 1957. The European Space Agency (ESA) estimates that there are more than 131,000,000 useless space waste objects, between 1 millimeter and 10 centimeters, currently orbiting around the Earth at an average speed of 36,000 kilometers per hour, which come from different sources such as last stages of rockets, satellites that are no longer operational, and even tools lost in space by astronauts.

"Any piece larger than 1 centimeter is potentially lethal in case of collision," says the Professor at the University of Malaga José Luis Torres, who, together with Professor Anelí Bongers, has coordinated a project on Space Economy that establishes, from a quantitative point of view, a theoretical model that determines the rate of satellite launches that is optimal to maximize benefits based on the amount of space debris.

Particularly, using data from the NASA and the ESA, the developed model is based on computational simulations that analyze the effects of anti-satellite tests on the amount of space debris and the probability of collision with operational satellites –there are currently around 6,000 satellites in orbit.