Freefall atomic or fusion scramjet to start engines on nosedive from platform 40 km up on a statospheric Balloons
The Balloons are tied by appropriate Kite string to the ground via a motorised Winch... a Stratospheric Elevator. An atomic scramjet then does a u turn from a straight down nosedive to start engines at around the speed of sound, to straight up, a half loop the loop the scary bit, then the spacecraft orbits Earth where the air is rare faster and faster to slingshot to Mars the Moon or upper atmosphere using rocket technology where there is no interstellar gases. This is easy for a small drone hard for something the size of the Saturn V needing a hundreds of stupidly big Balloons. Its way better than Rockets, and ,there are several recent advancements in fusion reactors, like, the superconducting Magnets Bill Gates funded to trap the fusion reaction in a magnetic trap. Mostly a 50 year old Richard Feynman idea. The Americans already have a fairly secret Flying isosoles triangle driven by nuclear power on each vertex. And thats nothing Google Pais Effect and find out everything you can, c