Explanations of the title: SLS == "The Space Launch System (SLS) is an American Space Shuttle-derived heavy expendable launch vehicle being designed by NASA":

Explanations of the title: SLS == "The Space Launch System (SLS) is an American Space Shuttle-derived heavy expendable launch vehicle being designed by NASA": https://en.wikipedia.org/wiki/Space_Launch_System https://en.wikipedia.org/wiki/Space_Launch_System "engineers who criticize" == legendary Chris Kraft, NASA's first manned spaceflight director, 2013 here: http://www.houstonchronicle.com/news/nation-world/space/article/Sunday-conversation-NASA-veteran-Chris-Kraft-4778332.php http://www.houstonchronicle.com/news/nation-world/space/arti...