[sokoloff]

We’ve been launching airplanes with steam catapults for many decades, albeit in an environment where we’re willing to take more risks than to go see Grandma, but many of the catapult concerns are areas where we have decades of experience and hundreds of thousands of successful cat shots.

[martyvis]

But the catapult isn't for saving on energy that needs to be carried on the aircraft. It's simply that you can't build engines and propulsion systems on a plane with the desired takeoff weight when you have as short a runway as you do on an aircraft carrier

[sokoloff]

Regardless of the underlying driver to implement it, we've solved some of the concerns that GP mentions for ground-assist launches, so there is a body of experience/work we can easily build upon.

[sitkack]

It is the same thing. The high power for takeoff shortens the runway from 7km to 400m.

We could do the same thing with cars and equip them with a super aerodynamic body and a 7kw engine, it could do 80kph.