Proposal of Frictional Dampers for Landing Legs’ Absorbers and Quick Review of Dropping Tests

Liquid spring damper for vertical landing Reusable Launch Vehicle under impact conditions

Landing Gear Drop Test (LGDT) utilizes the apparatus requiring a substantial time and cost. Virtual LGDT (vLGDT) using MSC ADAMS software is one of the solutions for initial stage to testing landing gear. From simulation with vsink 1.7 m/s and load 22000 N obtained contact/impact force that ensue in MSC ADAMS was 73650 N, while from experimental was 73612 N. The difference between vLGDT and LGDT result is 0.05 %. To obtain ground reaction load factor below 3 in vsink = 3.05 m/s, the rubber damper should have stiffness in the range of 1900 - 2100 N/mm and for the tire pressure of 60 - 65 psi.

Design and landing dynamic analysis of reusable landing leg for a near-space manned capsule

One of the important problems to be encountered in a lunar exploratory mission is the successful landing (touchdown) of a space vehicle on the surface of the moon. A description of vehicle response during landing will allow the prediction of the success of a lunar alightment. This paper presents an analytical procedure that describes the landing dynamics of a lunar alightment vehicle. The motion of an impacting vehicle is defined by the classical Eulerian equations of rigid body motion. These equations were integrated numerically by the digital computer to obtain particular solutions. Landing stability curves for a typical lunar vehicle were derived from the particular results obtained with this analytical procedure. An idealized model representing a typical lunar vehicle is used in making the analysis. This model incorporates the use of three crushable landing legs to accomplish the dissipation of kinetic energy at impact. This paper includes a discussion of the alightment concept and the effects of lunar surface characteristics. The results of vehicle drop tests conducted at the Space and Information Systems Division of North American Aviation Inc. also are reported.

Drop Test Description and Evaluation of a Landing Leg for a Re-usable Future Launche Vehicle