Purpose of the flight and payload description
D-SEND stands for Drop test for Simplified Evaluation of Non-symmetrically Distributed sonic boom and was a project carried out by the Aviation Program Group of the Japanese Space Agency JAXA between 2011 and 2015. It comprised a set of flight demonstrations of low sonic boom design technology which, as a key component of environmental compatibility, was considered as a high priority issue in the research and development of silent supersonic technology.
The D-SEND project was composed of two series of drop tests from a stratospheric balloon denominated D-SEND#1 and D-SEND#2. In the D-SEND#1 series, two different axisymmetric bodies were dropped and the sonic booms were measured and compared with each other. In the D-SEND#2 series, an experimental supersonic airplane model (unmanned aircraft with no engine and capable of autonomous flight) based on JAXA's low sonic boom design technology was dropped and the sonic boom was measured. In both series the sonic booms were measured and recorded by a microphone system that was tied to a line between the ground and a blimp floating at an altitude of 1 kilometer. These drop tests were carried out at the Esrange Test Site near Kiruna in Sweden.
Details of the balloon flight
Balloon launched on: 1/18/2011 at 9:52 utc
Launch site: European Space Range, Kiruna, Sweden
Balloon launched by: Swedish Space Corporation (SSC)
Balloon manufacturer/size/composition: Zero Pressure Balloon