Foam fractionation of heavy particles has been obtained aboard an aircraft that provides a low-gravity environment by flying parabolic trajectories. Results for large silica, glass, and steel pellets (>0.2 mm) show that, using minimally supporting froths, both mass transport and separation are possible. For single-pass batch separations in low gravity, concentration factors reached threefold (compared with a ninefold theoretical limit and no separation in unit gravity). The impact of reduced gravity is discussed for splitting large particle sizes from low surfactant fluids; possible interest includes bubbling premium biologicals (whole cells, proteins, and viruses, etc.) from native solutions without surfactant addition or membrane disruption.