SpaceX founder Elon Musk : `` Rocket landed on droneship , but too hard for survival '' This was the first attempt at historic rocket booster barge landing . Dragon spacecraft will head toward International Space Station on resupply mission .
SpaceX founder Elon Musk : `` Rocket landed on droneship , but too hard for survival '' This was the second attempt at historic rocket booster barge landing . Dragon spacecraft will head toward International Space Station on resupply mission .