SpaceX is credited as the very first developer of reusable rocket technology. Prior to the Falcon 9, their first spacecraft of this type, rockets would normally be designed for single use. After the delivery of the payload, they would either burn up upon atmosphere re-entry or suffer a controlled crash into the ocean. The SpaceX innovations that made it possible to reuse rockets (in part) consist of engines that can be used in both launching and landing, as well the development of superior lightweight and heat-resistant materials.