Problems with one of the on-board instruments couldn't be fixed: http://news.sciencemag.org/space/2015/12/nasa-delays-mars-insight-mission http://spacenews.com/mars-insight-lander-wont-launch-until-2018-if-it-launches-at-all/ http://www.spacepolicyonline.com/news/vacuum-leaks-delay-launch-of-nasas-insight-mars-mission 73s Bernhard VA6BMJ @ DO33FL