  Experiments in the early 1980s have shown that a compact bundle of quantum
vortex rings in superfluid helium remains coherent and travels a significant
distance compared to its size. This is surprising because a single vortex ring,
under the effect of friction with the background of thermal excitations (the
so-called normal fluid), would quickly lose energy and decay. The observation
of these long-lived vortex structures has remained an unsettled question since
their experimental detection. In this work, by taking into account the fully
coupled dynamics of superfluid vortices and the normal fluid, we show that the
motion of the superfluid bundle generates a large-scale wake in the normal
fluid which reduces the overall friction experienced by the bundle, enhancing
its lifetime. This collective effect is similar to the drag reduction observed
in systems of active, hydrodynamically cooperative agents such as bacteria in
aqueous suspensions, fungal spores in the atmosphere and cyclists in pelotons.
