NASA's now retired Space Shuttle program used a large amount of 1970s-era technology. Replacement was cost-prohibitive because of the expensive requirement for flight certification; the legacy hardware used completed the expensive integration and certification requirement for flight, but any new equipment would have had to go through that entire process – requiring extensive tests of the new components in their new configurations – before a single unit could be used in the Space Shuttle program. This would have made any new system that started the certification process a de facto legacy system by the time of completion.
Additionally, because the entire Space Shuttle system, including ground and launch vehicle assets, was designed to work together as a closed system, and the specifications did not change, all of the certified systems and components served well in the roles for which they were designed. It was advantageous for NASA – even before the Shuttle was scheduled to be retired in 2010 – to keep using many pieces of 1970s technology rather than to upgrade those systems.
Legacy System??-what is this? examples?
NASA's now retired Space Shuttle program used a large amount of 1970s-era technology. Replacement was cost-prohibitive because of the expensive requirement for flight certification; the legacy hardware used completed the expensive integration and certification requirement for flight, but any new equipment would have had to go through that entire process – requiring extensive tests of the new components in their new configurations – before a single unit could be used in the Space Shuttle program. This would have made any new system that started the certification process a de facto legacy system by the time of completion.
Additionally, because the entire Space Shuttle system, including ground and launch vehicle assets, was designed to work together as a closed system, and the specifications did not change, all of the certified systems and components served well in the roles for which they were designed. It was advantageous for NASA – even before the Shuttle was scheduled to be retired in 2010 – to keep using many pieces of 1970s technology rather than to upgrade those systems.
United States Secret Service using legacy systems http://www.ehow.com/about_6127997_define-legacy-system.html
-XP
-Mainframes
Apple's use of the NS prefix in code, due to the merger between Next Step and Apple.
Links:
http://en.wikipedia.org/wiki/Legacy_system
http://en.wikipedia.org/wiki/Mergers_and_acquisitions