Local Drives

Local drives are the normal drives that will be used inside a solar system. They are basically the drives the push the ship forward. Currently there is nothing to resist the thrust of a drive in space. A ship must be capable of withstanding the forces of acceleration without breaking through material strength and engineering alone.
There are multiple types of drives in common use:

• Reaction Drives: These are classical drives, dump something in and you get pushed forward
  • Chemical Thrust Drives: These are the big rocket engines, that use the expansion of gas to push the rocket forward
  • Impulse Drives: Use Newton's third law of motion. Something is shot out from the engine, and the law of conservation of momentum kicks in. The momentum is transferred to the ship.
• Energy Conversion Drives: These are drives that convert energy into kinetic energy. It may work in a similar way to the EmDrive that NASA tested in the early twenty-first century, but scientists are tight lipped about the exact nature of the drive. Currently with about 300 years of development the drives are about 30% efficient. The rest of the energy is wasted as heat.

There are other types of engines under development.

• Gravity Drives: Shhhhhh its a secret. [Author's Note: I had planned on including these in the first book but did not.]