Envision an engine that does not require propellant. It seems unfeasible, and it probably is.
Despite this, a NASA engineer is still investigating
possibilities regarding the EmDrive, a hypothetical "helical" engine
that would overcome gravity and generate forward thrust without the need for
fuel.
This could be the most exciting technological development of
the century, enabling humans to go to the furthest reaches of space.
What is the EmDrive?
In 2001, British physicist Roger Shawyer proposed a theory
that proposed using microwaves to pump energy into a conical chamber in order
to create thrust.
Theoretically, according to Shawyer, the microwaves would
bounce off the chamber walls exponentially, producing enough propulsion to
operate a spacecraft without fuel.
It is true that some researchers assert to have produced
thrust during EmDrive tests. However, the amount was so small that the critics
speculate that external factors might even have contributed to the thrust. The
Earth's magnetic field or seismic vibrations could be causing this.
New Research
In recent months, a number of scientists and engineers have
expressed opposing views regarding the EmDrive.
While some have said it's impossible, others have persisted
in working on what may be a pointless endeavour, arguing that the effort will
be worthwhile in the end.
According to New Scientist, NASA engineer David Burns is the
most recent of these.
According to Burns, "if you had enough time and power,
the engine itself could reach 99 percent the speed of light." Burns stated
this to New Scientist.