Since the beginning of space exploration almost 70 years ago, tens of thousands of satellites have returned to burn up in our planet’s atmosphere at the end of their mission. But paradoxically, specialists are still far from fully understanding everything that the machine is undergoing at this time. To fill this gap, ESA is preparing a mission focused on a veritable kamikazewhose sole responsibility will be to collect valuable data on this critical phase of many space missions.
The satellite at the heart of this program is called Dracopour Destructive Reentry Assessment Container Object. This is a rather unusual machine the size of a washing machine. Indeed, it will not be equipped with any propulsion system, and for good reason: it is not intended to be controlled at all. His mission will only consist of falling like a stone, after being launched by a rocket on a very precise trajectory which will start at an altitude of approximately 1 kilometer and will bring it directly to the surface without going through a stable orbit.
Atmospheric reentry, a critical but poorly documented phase
The objective of this surprising approach is not to produce a small fireworks display costing several million euros. It’s actually about answering a bunch of crucial questions about the end of life of small spacecraft. During their fateful plunge towards the Blue Planet at several tens of thousands of kilometers per hour, as the density of air particles increases, these machines are subjected to absolutely dantesque mechanical and thermal constraints. In the majority of cases, this leads to their almost total destruction; only a few specific types of craft, such as those which carry samples collected from another celestial body or the Starship, include elements designed to withstand such a furnace.
As a general rule, operators are not particularly interested in this flamboyant carcass. They often simply calculate a trajectory that does not pose a risk to humans below, because at this point, the majority of devices have already completed their mission and transmitted all their data.
This approach works relatively well, and has the advantage of unclogging the Earth’s orbit which is beginning to suffer from a serious congestion problem. But this also means that we are seriously lacking data on how this destruction is unfolding and how it is affecting the atmosphere. And it is these gaps that Draco will try to fill.
An angel’s leap in the service of future satellites
To do this, Draco will be able to count on an arsenal made up of 200 sensors housed in an armored capsule. Throughout its fall, it will record a lot of data (pressure, temperature, mechanical constraints, etc.), and four on-board cameras will also allow engineers to collect additional context elements to complete the analysis. They will therefore know precisely how each part of the device will be affected by friction with the atmosphere.
Once the external part of the device is completely disintegrated, only the internal capsule containing the data will remain. The latter will have to stabilize very quickly to deploy a parachute. From there, Draco will have around twenty minutes to transmit the fruit of his collection before finishing his race in the ocean.
In total, the mission will only last around twelve hours, which is extremely short. But the game is worth the effort, because several generations of future satellites will be able to benefit from the data that Draco will bring back.
« The science of atmospheric reentry is an essential part of the design. We need to better understand what happens when satellites burn up in the atmosphere and validate our re-entry models,” explains Holger Krag, head of space security at ESA. “That’s why the unique data collected by Draco will help guide the development of new technologies “, he specifies.
We will still have to wait a little to benefit from it, since Draco will not be launched before 2027. But it will be very interesting to see how the data it will bring back will influence the development of the next players in space sciences.
Source: www.journaldugeek.com
