A variety of hypothetical propulsion techniques have been considered that would require entirely new principles of physics to be realized or that may not exist.

Douglas Pace was convinced that the spheroid disc was the single most vital component of the new high-altitude propulsion techniques.

This course emphasizes planning, procedures, environment, propulsion techniques, buoyancy skills, problem solving, equipment modification and the focuses on the specialized needs of the cavern diver.

Other potential propulsion techniques such as ornithopters are very rarely used.

AUVs can rely on a number of propulsion techniques, but propeller based thrusters or Kort nozzles are the most common by far.

The propulsion technique gives the quarrels extremely high stopping power.

Another propulsion technique, creating high launch velocities, involves the use of elastic bands for "catapults".

Training will generally consist of gas planning, propulsion techniques needed to deal with the silty environments in many caves, reel and handling, and communication.

Sirius is a 2013 documentary film that follows the efforts of Steven M. Greer to reveal information about top secret energy projects and propulsion techniques.

We also do not know the propulsion technique that they use in space.