new megarocket NASA postpones dress rehearsal of new megarocket 4 years ago The final major test of NASA's Space Launch System (SLS) rocket was called off today due to pressurisation concerns that… The first flight of NASA’s new megarocket, Artemis 1, will not take place until May 4 years ago NASA's Artemis 1 lunar mission could be delayed until the summer. Artemis 1, which would fly an uncrewed Orion spacecraft…