That would certainly help get the aircraft up to a speed where it has usable lift and can leave the ground. That's a good headstart, and it represents a significant amount of energy.
A catapult launch can't help with the next 30,000 feet of climbing, though, while the impossible umbilical might.
A catapult launch can't help with the next 30,000 feet of climbing, though, while the impossible umbilical might.