Performance Evaluation of a Second-Generation Elastic Loop Mobility System.
Abstract
Tests were conducted to evaluate the mobility performance of a second-generation Elastic Loop Mobility System (ELMS II) developed by Lockheed Missiles and Space Company for the National Aeronautics and Space Administration (NASA). Performance on level test lanes and slopes of lunar soil simulant (LSS) and obstacle-surmounting and crevasse-crossing capabilities were investigated. In addition, internal losses and contact pressure distributions were evaluated. To evaluate the soft-soil performance, two basic soil conditions were tested: loose (LSS1) and dense (LSS5). These conditions embrace the spectrum of soil strengths tested during recent studies for NASA related to the mobility performance of the LRV. Data indicated that for the tested range of the various performance parameters, performance was independent of unit load (contact pressure) and ELMS II drum angular velocity, but was influenced by soil strength and ELMS pitch mode. Power requirements were smaller at a given system output for dense soil than for loose soil. The total system output in terms of pull developed or slope-climbing capability was larger for the ELMS II operating in restrained-pitch mode than in free-pitch mode. The angle of the maximum slope that the ELMS II climbed in free-pitch mode on dense soil was 35 deg; on the same soil, but with the system operating in restrained-pitch mode, the angle of the maximum climbable slope was 34 deg, and on loose soil, it was 27 deg. The smaller maximum slope angles for restrained-pitch mode resulted from load being transferred from the ELMS II to the trailer, which was used during the slope tests to stabilize the single unit.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1974
- Accession Number
- ADA031772
Entities
People
- G. D. Swanson
- Klaus-jergen Melzer