Ignition Test for HTP/PLA/KMnO4 Hybrid Fuel Core
This test examined the ignition time of the PLA/KMnO4 fuel core after weeks of storage in a dry bag. Ignition was in ~ 0.6 sec with a burn time of ~ 6.0 sec. The shorter the ignition time the longer the burn time for a given amount of propellant. The total propellant mass is ~ 115 gm, just under the FAA regulation for a class I rocket. The fuel core was in a zip lock bag with desiccant for 24 days. There were three test, the first was stored in dry bag for ~ 6 months, the second for 24 days, and the third for 31 days. All other parameters were the same. Ignition times varied from 0.4 sec to 0.6 sec. As such, The procedure is to store PLA/KMnO4 hybrid fuel cores in a dry bag for a minimum of two weeks and as long as four weeks.
The endoscope video shows a nice even burn of the fuel core. The video begins at the injector end and backs out to the exit. The six point design is clearly visible. The injector evenly distributes the spray around the fuel core. On closer examination, one can see the cone angle of the spray. Backing out, there is an even burn distribution. The purplish color is due to the reflection from the LED light on the endoscope, not the color due to the fuel. Reference the blog on www.fisherspacesystems.com for end of month report.