This time we made a batch of six engines with the intent that they were all "the same". But they weren't quite identical.
- 12a when we were doing the heating there was still some soot in the pan from burning the test 11 residuals, and the mix was significantly darker looking.
- 12 ab – the first half (toward the nozzel) was filled with the sooty material like 12a, but the rest was with a second melt as was 12b
- 12b – filled with a clean melt
- 12c, 12d – filled with a clean wet melt that cooked for longer than 12b
- 12e – filled with the same melt as the 12c & 12d, but without a fuse.
12a, 12ab, 12b. (12c not shown), 12d, 12e
Tests
(in the order they were conducted)
- RCET 12c: where'd it go?
RCET 12a: oh no, not again
RCET 12ab: stay
RCET 12b: weaksauce
RCET 12d: holy scat- We have not yet tested 12e due to problems with the launch controller.
After test 12a we added a restraining pin to the test rig. This was done at the suggested of one of our venerated old ones (now a college student) who was visiting for the day. It wasn't subjected to a think through all the failure modes you can think of discussion. As the test of 12d showed, it probably should have been. Especially considering how some of his innocent sounding ideas have played out in prior years. Just saying.
Conclusions
- We overfilled some of these engines, and possibly under-filled others.
- The plugs don't hold, possibly because
- they were too thin,
- they were right at the end
- there was fuel around the edges that prevented them from gripping
- We need to analyze the plug failures
- We don't need to come up with a new formula for an ejection charge
- Our consistency is rubbish
- There is still more science to do