Space Rider is set to become the first reusable European spacecraft. This uncrewed robotic laboratory will remain in low Earth orbit for approximately two months. Space Rider’s cargo bay will accommodate a wide variety of experiments and operations. At the end of its missions, the reentry module will return to Earth, landing via an automated parafoil glide.
Any spacecraft returning to Earth hits our atmosphere at speeds exceeding 27,000 kilometers per hour. At these velocities, particles in the upper atmosphere strike the spacecraft so intensely that frictional heat builds up — the gases become ionized, and the spacecraft becomes enveloped in a burning ball of plasma with temperatures easily surpassing 1,600 degrees Celsius.
Ceramic Tile Testing
Spacecraft that return to Earth, such as Space Rider, must protect themselves from these extreme temperatures. Space Rider uses reusable ceramic tiles on its belly and nose to insulate against the heat. The spacecraft features 21 tiles made of ISiComp, a ceramic material developed by the Italian Aerospace Research Centre (CIRA) and Petroceramics, forming a lightweight and resilient thermal protection system. The tiles were first tested in February when they were subjected to the severe vibrations generated by the Vega-C rocket’s powerful engines, simulated on a 200 kN shaker.
Flaps for Hypersonic Heated Control
Space Rider’s reentry module is unique because it can generate lift like an aircraft and target a precise landing point — but instead of wings, Space Rider’s body itself provides lift. The reentry module has two flaps to steer the spacecraft during reentry. Weighing just 10 kilograms and measuring only 90 by 70 centimeters, these flaps steer the 3,000-kilogram module as it flies through Earth’s atmosphere at hypersonic speeds. Made of the same ISiComp ceramic material, the thermal protection is fixed with titanium alloy supports produced through additive layer printing. The flaps are controlled by the spacecraft’s avionics “brain.”
To test the flaps as if they were in flight, CIRA subjected them to its plasma wind tunnel — the world’s largest. The flaps were bombarded with an arc jet of gas at ten times the speed of sound.
Space Rider has been acing its tests so far, even surviving reentry conditions with a purposefully damaged tile — just in case the spacecraft were to be struck by a micrometeorite while in orbit. More tests await Space Rider’s thermal protection system and guidance system before they are qualified for spaceflight — and reentry.
