Experiment Outline
The objective of the experiment is to measure UHF radar backscatter from a cloud of charged microparticles released above 80 km.
We plan to measure the radar backscatter from a metal cloud with predefined properties dispersed in the mesosphere. Spatial extent, particle density and particle sizes within the metal cloud will be measured with an onboard imaging spectrograph recording sunlight scattered on the microparticles. Flight characteristics of the FFUs will be recorded using accelerometer, angular rate sensors, and GPS receivers for post flight analysis of the cloud dispersion.
The experiment will deploy two identical free flying units from the rocket module. These units will release metal dust into the mesosphere close to the apogee of the rocket. Two alternative methods for the release of the dust are being investigated. The first method is to spray liquid suspension of the metal dust through a nozzle. The second method is to spread the metal dust using gun powder.
The backscatter measurements will be taken using the EISCAT UHF radar operated by European incoherent scatter (EISCAT) organization. The radar facility is situated near Tromsø, Norway. The radar dish is fully steerable and at low elevation the radar beam intersects with the rocket trajectory. When the rocket is on the down-leg the radar will be operated and radar data will be monitored in real time.
Prior to the rocket launch, during countdown, the radar will be operated to measure mesospheric background properties. Shortly before rocket launch the radar transmission will be paused. At an altitude of about 60 km the FFUs will be ejected from the spinning rocket. Close to apogee metal dust will be released from the FFUs. The release process will be monitored with optical diagnostics and stored onboard the FFUs for post-flight analysis. For landing and recovery systems of the FFUs we will use the heritage from previously successful experiments by KTH REXUS teams. Approximately 150 s after rocket launch when the rocket is on its downleg the EISCAT radar will again be operated with transmitter power to measure backscatter due to the injected particles.