Report

Dordrecht, 13 February, 2005 - On this very cold and wet winter day we had a new motor test. The last test, CMT0410, wasn't a success, because the pressure was to high and the safety mechanism kicked in. So a throat of 12mm was to small. To have a good test result this time, we had a throat of 13.5mm in the new test. It wasn't expected that the test motor's results were to be very good. The motor was expected to function as planned this time.

Between the rain-showers and hail we had set up the motor test stand. When we were ready preparing the motor the weather cleared. So finally the test started. The motor preformed very well and it burned relatively long and was loud. We started to dismantle the test stand first, because it was still dry. Then we checked the results. The motor pressure was at its maximum 9.3 bar (930kPa), which was quite below that of the last test. The motor burned for 13 seconds, which is longer than the final motor has to burn. C* is 753m/s and the specific impulse Ismax is 96s. These results showed us, that we already have a fine second stage motor with a very good pressure curve, but we want a motor with a higher pressure and shorter burn time. So the next test shall have a smaller throat. Most likely this will be a 13mm throat.