May 10th 2013 Meeting Report

At the meeting we mostly discussed the results of April 27th launch. Regarding safety we discussed the USC launch in particular. Our the pyrotechnic operator for the launch Jim Gross mentioned that the UCS guys did better about reducing the number of people around the loading station. However he also expressed that they could still be more organized in their efforts on launch day. (For example they were speed drying epoxy with a blow dryer prior to launch) Although we are aware that this is a college project and the added constraints, particularly with time, that come along with that. He also noted that he was not made aware of the flight computers safety feature to not ignite the second stage depending on the flight trajectory and felt that this was important information for the pyrotechnic operator to be made aware of. A suggestion was made that some sort of prelaunch presentation or review of the flight software would be very beneficial.

Regarding launches in general it was expressed that we want to be more diligent about having people who are launching fill out a flight data sheets with information like max altitude and the range of the recovery area. This was apparently something we were more diligent about in the past but we have lapsed on its enforcement. I made the suggestion that if we implement this again we should also make as simple guide as possible showing how to calculate those numbers for anyone new to the process.

We also discussed the possibility of having a special meeting in September but the details aren’t set. The USC guys would like to host a meeting at their Lab on the USC campus, so they can show us all the neat stuff they have going on there and how they’ve been building their rockets. That promises to be interesting so don’t miss it.

I also had the opportunity to show everyone my tilt sensor. After seeing Osvoldo’s magnetic apogee detector and hearing about a mercury based tilt sensor for parachute deployment I decided I needed to make something like that for my rocket. It’s just a simple tilt sensor hooked up to an Arduino microcontroller. The Arduino is programmed to check that the device has been armed, and count how long the sensor has been activated. That way any jostling won’t set it off. Only when it’s held on, as when it will when the rocket reaches apogee and leans over, will the parachute be deployed. Based on feedback that I got I will run it in a test configuration first (launched on a rocket but not controlling deployment) to see how it behaves and how long if at all the deceleration phase, after burnout and before apogee, will set off the switch. Based on the results I may need to adjust the programming and have it ignore the first activation caused by deceleration, or I may have to abandon the idea entirely.

Eric Claypool showed up and he gave me a hard copy of the files of the media that are currently on the RRS website.[the previous site] We discussed what to do next with the website; the First thing to do is install WordPress on the server. Once that happens I can start working on a live version of the new site under a different address. Once we’re satisfied we then just switch the address. Eric also brought his LOX/Alcohol rocket engine for us to take a look at.

Next Meeting: June 14th Gardena Recreational Center, 1670 West 162nd Street Gardena, CA
Next Launch/Static test has been set for October 5th at the MTA

Regarding the next launch, I don’t know what anyone else is working on for it but here is what I hope to have ready. Sucrose/potassium nitrate motor static test and flight test with additional testing of an Arduino based flight computer, and a static test of my peroxide/gasoline engine. I also hope to do some testing for a hydrogen peroxide based quasi-hypergolic ignition system (where the heat from the decomposition of the peroxide ignites the propellants.) I haven’t done any detailed design yet but I’ve found a reasonable vendor for 30% peroxide and a lab glassware vacuum distilling kit on ebay, so I may be cooking up some peroxide at some point soon. If you need some let me know, but I don’t plan to make a lot.


-Richard Garcia

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