Ballistic Test Motor (BATES)
SPL is primarily focused on development for liquid propulsion, but solid propellants will also be used for SPL projects. Areas of potential application include separation devices, pyrotechnic actuators and - in a later phase - strap-on boosters. Therefore, basic experiments are performed to get some hands-on experience in that field.
BATES (Ballistic Test) motor. It is designed to take up a 50 mm x 220 mm  grain with a 20 mm core. It uses components of our smaller C* burner which is used for propellant characterization with end burning grains. In case of an overpressurisation, grooved bolts will release the end closures (happened with the first of two firings in the occasion of our meeting last saturday due a defective grain). The case itself is rated up to 50 MPa.  A close-up of the igniter used in the BATES motor. We designed the igniter not only to release heat, but also pressurizes the chamber to an appropriate level. A small squib initiates a charge flash powder, black powder and pellets. With this igniter the motor needs only  20 ms to reach its full working conditions!
This graph shows the pressure-time curve. The progressive burn is a result of the grains geometry and some deposits of Al2O3 in the graphite nozzle. A close up of the BATES grain. The receipt of the grain can be found here