[marktwain]

Why would you need to put it in orbit?

As much thrust as he is talking bout should be easily detectable here on earth.

[Rockingham]

The thrust has been measured in test rigs on earth. The point of putting a working device in orbit is to prove it in that environment.

There is a valuable immediate market for even a small thruster to maneuver satellites and keep them properly oriented. If it did not use propellant and lasted indefinitely, it would radically simplify satellites and make them last much longer.

The revenue and experience in that market could then facilitate the development of better and more powerful thrusters that could be used in manned spaceflight.