page_title: Steering
section_title: Steer-by-wire
hierarchical_section_title: Steering / Land vehicle steering / Steer-by-wire
caption_attribution_description: English: The Lunar Roving Vehicle (LRV) was a battery powered "dune buggy" taken to the moon on Apollo missions 15, 16, and 17. The LRV was stowed on the descent stage of the Lunar Module and deployed upon arrival at the lunar surface. The LRV was operated with a spacecraft "stick," rather than a steering wheel, and could move forward and backwards. In addition to the flight vehicles, Boeing manufactured eight non-flight units for development and testing. One, the "Qualification Test Unit," was a very close replica of the units that flew. Using special test chambers, engineers purposely subjected the qualification unit to conditions many times as severe as those expected on an actual mission. When the tests were finished, given the stresses it had been subject to, the qualification unit could not safely be used in space. In 1975, NASA transferred it to the Museum.
context_page_description: Steering is a system of components, linkages, etc. which allows any vehicle to follow the desired course. An exception is the case of rail transport by which rail tracks combined together with railroad switches provide the steering function. The primary purpose of the steering system is to allow the driver to guide the vehicle.
context_section_description: The aim of steer-by-wire technology is to completely do away with as many mechanical components (steering shaft, column, gear reduction mechanism, etc.) as possible. Completely replacing conventional steering system with steer-by-wire holds several advantages, such as:
  The absence of steering column simplifies the car interior design.
  The absence of steering shaft, column and gear reduction mechanism allows much better space utilization in the engine compartment.
  The steering mechanism can be designed and installed as a modular unit.
  Without mechanical connection between the steering wheel and the road wheel, it is less likely that the impact of a frontal crash will force the steering wheel to intrude into the driver's survival space.
  Steering system characteristics can easily and infinitely be adjusted to optimize the steering response and feel.
  As of 2020 there are no production cars available that rely solely on steer-by-wire technology due to safety, reliability and economic concerns, but this technology has been demonstrated in numerous concept cars and the similar fly-by-wire technology is in use in both military and civilian aviation applications. UN 79 regulations  [2003] allow for no mechanical connection between the driver and the steerable wheels.
caption: 1971 Lunar Roving Vehicle (LRV) with joystick steering controls.
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