A test flight for SpaceX's Starship, a rocketship Elon Musk hopes will carry people to Mars in four years' time, ended in a spectacular explosion upon touchdown on Wednesday night. The bullet-shaped rocket underwent its most elaborate flight yet, aiming for eight miles up towards the stratosphere, nearly 100 times higher than previous flights. Elon Musk, the billionaire entrepreneur behind SpaceX, called it a successful ascent, and claimed "we got all the data we needed" following the mission. The full-scale prototype, 50 meters and 9 meters in diameter flew over the Gulf of Mexico following a successful launch. After about five minutes, it turned sideways as planned and descended in a free-fall back to the southeastern tip of Texas near the Mexican border. The Raptor engines reignited for braking and the rocket tilted back upright. When it touched down, however, the rocketship exploded. Musk had said earlier this week there was "probably" a one-in-three chance of complete success. Wednesday's test followed SpaceX's latest space station supply run for NASA by three days, and the private company's second astronaut flight by less than a month from Florida's Kennedy Space Center. Starship is actually the upper stage of the ships Musk hopes will take people to the moon and Mars. It will launch on top of a huge booster, still in development, known as the Super Heavy. SpaceX intends to use Starship to put massive satellites into orbit around Earth, besides delivering people and cargo to the moon and Mars. Earlier this year, SpaceX was one of three prime contractors chosen by NASA to develop lunar landers capable of getting astronauts on the moon by 2024.