"During the test of the deployment system for the
vapor clouds, four sub-payloads with mixtures of barium and strontium will be ejected from the main payload and the vapor will be deployed while the payload is descending. The test also will include the release of vapor from two systems on the main payload during the descent portion of the flight. The vapor tracer sub-payload deployment method being tested on this flight uses small rocket motors to eject the sub-payloads from the main payload. The ejected sub-payloads will release the vapor at about 130 miles above the Earth. The main payload releases will occur at an altitude around 118 miles. The barium-strontium mixture produces a cloud with a mixture of blue-green and red color. The blue-green part is neutral, i.e. not charged. Strontium is used to enhance the visibility of the neutral flow."