In the early history of the Time Lord civilisation, stasis haloes protected the ships of a Gallifreyan fleet from "the maelstrom" of a growing black hole, which would have given them the power of time travel. (COMIC: Star Death)
Fenris the Hellbringer, agent saboteur of the Order of the Black Sun, (COMIC: 4-D War) infiltrated the flagship Aeon and with a wave scrambler he operated on the stasis field generator, switching off the protective haloes. The whole fleet was to be sucked into the black hole; in particular Omega's ship broke up because of the gravitational pressure. The secret intervention of Rassilon switched back on the haloes and saved the rest of the fleet. (COMIC: Star Death)