A comparison is made of recent reduced gravity flow boiling data obtained using two test facilities which utilise different measurement techniques. The specifications and parameters of each test rig are described with both featuring 6 mm tubular channels through which either HFE-7000 or HFE-7100 is boiled. Parabolic flight campaigns provide the microgravity environment in which heat transfer and void fraction measurements are coupled with flow visualisation to provide into gravity’s effect on twophase flow.