An experiment is described that is expected to trigger an ionospheric "bubble" in the equatorial F region: i. e. the rise of a flux tube with low plasma content from the bottom of the post sunset F region. The disturbance which will be applied to this region by means of sounding rockets consists of two barium plasma injections at 280 km altitude, separated by 50 km in E-W direction. The low density space between the two clouds is expected to act as the nucleus of bubble formation. It is demonstrated that two conventional barium releases, if placed at the right altitude, are sufficient to create the desired initial perturbation. The development of the bubble can be observed by various optical and radio techniques such as incoherent scatter, backscatter, ionosonde and radio scintillation measurements from ground and aircraft. The long-range perturbations introduced by the rising flux tube will be monitored by airborne airglow measurements in the southern Appleton anomaly. Two rcokets will be flow from the Punta Lobos range south of Lima/Perú on a westward trajectory with a range of about 400 km