High-velocity, high-altitude aspects of the booster atmospheric return technology began testing in late 2013 and have continued through 2018, with a 98% success rate to date. As a result of Elon Musk's goal of crafting more cost-effective launch vehicles, SpaceX conceived a method to reuse the first stage of their primary rocket, the Falcon 9,[39] by attempting propulsive vertical landings on solid surfaces. Once the company determined that soft landings were feasible by touching down over the Atlantic and Pacific Ocean, they began landing attempts on a solid platform.