Verification of Landing Systems Touchdown Dynamics - A Status Report of a German Joint Co-operative Team on Landing Technology

Abstract

One major milestone during the development of a landing system for robotic or manned exploration is the analyses and verification of the design in a laboratory on Earth. Prerequisite for a successful verification is a realistic representation of the target landing site properties. In particular the lower Gravity as it is present on Moon, Mars, comets or asteroids is a key driver for the design of the landing subsystem with respect to landing stability issues. The Joint Team Co-operative "Landing Technology" with members from the DLR Institute of Space Systems and the Astrium GmbH, Bremen, is focussing on the development, evaluation and verification of experimental and analytical methods for the investigation of the touchdown dynamics and landing system design. Core element for the experimental investigation is the DLR Landing & Mobility Test Facility (LAMA), which allows dynamic touchdown testing under a reduced gravitational environment using a six axis KUKA robot as active off-loading device. The test specimen for the investigation of the landing system is a representative Lander Engineering Model (LEM) designed, sponsored and equipped by the Astrium GmbH, Bremen. The design of the LEM is driven by today's European missions to Moon and Mars with focus on the support of the European Lunar Lander. The paper will present the latest achievements of the working group based on a preparatory test program for the stepwise increase of the technological maturity of the key elements of a landing system with landing legs and two drop test campaigns with the LEM. The representativeness of the testing environment for touchdown dynamics on Earth and the analytical models will be critically discussed and evaluated with respect of today's needs in the running European programs.