"Airbags?" Mai Dong and Tang Yue nearly answered at the same time.
In the early Mars exploration missions, the engineers used a rather simple and crude solution to deal with the final stage of landing—the last tens of meters—by using airbags.
By wrapping the probe in an airbag, they allowed it to crash straight into the Martian surface and decrease its altitude and energy by repeated bounces. In essence, it was no different from the safety airbags in a car. It was ancient and simple, but rather reliable. After the probe was detached from its parachute, it would rapidly pump up an airbag, allowing itself to be wrapped in a protective ball.
Before a high-end Martian rover like Curiosity was put into use, many pioneers that headed to Mars had relied on such simple spherical airbags to protect themselves.
"Where do we get the airbag from?" Tang Yue asked.
