Now that rockets can be recovered and reused, hydraulic buffers are an indispensable core assistant. When a rocket returns from the sky, the biggest fear is a "hard landing." The hydraulic buffer is like an "intelligent shock-absorbing pad" installed on the rocket, capable of precisely dissipating impact forces. Its performance directly determines whether the rocket can land safely and be used again next time.
The biggest headache in rocket recovery is the landing impact—the first stage booster, weighing several tons, still has a velocity of several meters per second at touchdown, generating an impact force comparable to a hundred-ton object slamming down. The hydraulic buffer's "force-dispelling secret" is quite ingenious: its internal piston rod compresses the fluid, converting the rocket's impact force into heat energy and slowly dissipating it, while an internal gas chamber can further "catch" it, preventing hard impact from damaging the rocket. For example, SpaceX's Falcon 9 relies on it to keep the impact within a safe range, equivalent to the body weight instantly becoming five times without injury, and all critical components are preserved.
Hydraulic buffers are also particularly "flexible," able to handle even the most complex recovery scenarios. When Blue Origin's rocket recovers at sea, for instance, the recovery ship sways with the waves, and the buffer can adjust its "force-dispelling" intensity in real time, allowing the rocket to stand steadily on the ship. In China's reusable rocket tests, the buffer has even achieved the capability of "extending legs in the air first, then absorbing force upon landing," filling a domestic technological gap.
Not only is it capable, but it is also exceptionally "tough," unafraid of extreme environments. When a rocket returns from space, temperatures can drop to minus 45°C and then rise to 200°C. Yet the buffer uses specially formulated sealing materials and high-and-low-temperature-resistant oil, and its performance is completely unaffected. Compared with older cushioning devices, it does not bounce back and cause the rocket to sway. After simple inspection and maintenance, it can be used again. The Falcon 9's cushioning system can withstand more than 10 recoveries, greatly reducing launch costs.
Whether on a land-based recovery pad or a floating platform at sea, hydraulic buffers are evolving alongside rocket technology. There is now even a new mode of "catching the rocket with a large net." Cooperating with related devices, it can loosen the requirements for rocket landing and help humanity explore space more economically and safely.
