Force field

A force field is a device which is often used to protect whatever it surrounds for various reasons. They are usually transparent in colour, the only evidence of their existance being when an object hits the field.

Humans developed force fields sometime before 43K2.1 and used them to surround bases on hostile planets during missions. The base on Krop Tor used force fields when scientists traveled to the planet to find and retrienve the energy source that was keeping Krop Tor in orbit of the black hole K37 Gem 5. However, the force field was only used to cover an openable roof, and air could easily escape if a window was destroyed. (DW: The Impossible Planet/The Satan Pit)

When the Judoon transported the Royal Hope Hospital from London to the Moon in 2008, they created a force field around the hospital to keep the air in. The Judoon though were able to enter and exit the field while the people in the hospital were stuck inside. (DW: Smith and Jones)

A tribophysical waveform macro-kinetic extrapolator is a pan-dimensional surfboard used as a kind of spacecraft, surrounding the user in a force field to protect them. (DW: Boom Town)