Generally speaking, natural graviton fields appeared to be more powerful than man-made fields such as the one encountered by the USS Enterprise-D in 2367. (TNG: "The Loss" ) Later that year, the Cytherian-influenced Reginald Barclay modified the Enterprise nacelles to create a highly charged graviton field, which created a subspace distortion and enabled the ship to travel to the Cytherian homeworld. (TNG: "The Nth Degree" ) In 2369, the graviton field of Deep Space 9's tractor beam was able to stabilize Tosk's starship's structural integrity. (DS9: "Captive Pursuit")