A major goal of SpaceX has been to develop a rapidly reusable launch system. as of march 2013, the publicly announced aspects of this technology development effort include an active test campaign of the low-altitude, low-velocity Grasshopper flight test vehicle,[47][48][49] and a high-altitude, high-speed Falcon 9 post-mission booster return test campaign. In 2015, SpaceX successfully landed the first orbital rocket stage on 21 December 2015.