Abstract
The spacecraft needs to decrease falling velocity to protect its body against the landing impact. This paper proposes a new method using momentum exchanging to decrease falling velocity. The momentum exchange device is composed of a compressed spring and an auxiliary mass at the under part of the spacecraft. Just before the landing, the spring is released and the mass is discharged toward the landing surface, consequently a part of momentum of the body of spacecraft is moved to the mass, and velocity of the spacecraft is decreased. This phenomenon is investigated theoretically and experimentally. The results show that the velocity can be decreased remarkably.
