Tesla and SpaceX are both iterative technology. They both use existing technology and iterate improvements on it or apply it to new fields. The electric car was already proven feasible by GM and other companies or products like golf carts. It was more of a problem of the existing players being forced to build an electric car than keep doing what they've been doing to generate profits.

SpaceX still uses rockets. The new tech in SpaceX is changing the rocket design between engines so it is manufacturable in larger quantities and utilizing faster computers to create reusable rocket stages that can land with their own power back on Earth. You could say that SpaceX is leveraging computer science artificial intelligence research, the general improvement in computing (cost and speed), and sensors. For example there are many videos of software controlled quadcopters performing various aerobatic stunts by analyzing and adjusting thrust in realtime based on sensor information.