Today I successfully launched my first amateur rocket and simultaneously obtained level 1 certification with the National Association of Rocketry.

I launched a Norad Pro Maxx rocket, which is a kit-built rocket from LOC-Precision, with an H-128W-M motor. Winds were heavy (to the point that I felt them pushing against my car as I drove up to the launch site), but we set up the rocket, and hooked it up on the launch pad. Then we waited for a lull in the winds. Waiting, waiting, trying to guess whether or not they're calming down, or if it'll pick back up in a second. Waiting, waiting.... NOW! We launch the rocket! The H motor lights up with a precise roar and shoots for the sky. Burnout occurs quickly, and we watch the rocket as it starts arcing over, travelling further than I thought it would given the 80 degree launch angle. POOF. The ejection charge pushes the parachute out and we have successful recovery system deployment! The wind carries the rocket back over the launch pad and keeps going...

With the help of a couple sharp-eyed members of the Indiana Rocketry Society we found the rocket in a cornfield (of course we found it in a cornfield, this IS Indiana after all) about 0.5-.75 miles from the launch pad (which, by the way, was also in a cornfield!). Everything looks intact, except for a small "zipper" at the parachute attachment point of about 2-3 inches. Slap some 1/16" or 1/32" plywood over that and it'll be good to go again :)

Max altitude recorded: 28942m     Total distance convered: 81.9km     Flight time: 1h 52m
Ability of payload box to withstand impact with the ground at 56 mph after dropping from ~29km without a parachute: surprisingly good!

We conducted another radio range test today. This time I decided to go as far as possible on Union street and just see if it would work at all - this is beyond Line of Sight (LOS).

Surprisingly it did! Total range measured using Google Earth was 4.14 miles.

The test consisted of two moxon antennas. One was hastily constructed using 6 gauge copper wire bent roughly to form, and using a ruler to mark the correct spacing.

The other was precision machines on a CNC router. Unfortunately, the machine screwed up a little bit, so some of the elements are a little mangled, but the spacing between the elements was precise. I was hoping this increased precision would help with signal quality, but it doesn't seem to have had much of an effect. Both antennas were able to successfully receive data from the payload over 4 miles away, in various orientations. Click after the jump to see photos of both antennas

I finally got the antenna for the Lassen IQ today, and after hooking it up and leaving it alone for quite some time the unit finally got a good enough GPS signal to determine its position and altitude.

I'm glad that it's finally getting data, but I'm a bit disappointed in the quality of the unit. Whereas the Garmin got signal almost instantly, and the Inventek could take a couple minutes, the Lassen took quite a while, perhaps up to 10 minutes (I didn't keep track). More worrying is that it only sees something like 4 or 5 satellites, whereas the other two units would see around 10 +/- 2 when they had signal.

I'll try using some scrap sheet metal to make a better ground place for the antenna, hopefully that will increase reception. Also the unit will have somewhat fewer obstructions as it flies through the air, but still, it would be less worrying if it didn't have such a weak signal to begin with.

Today my team and I successfully conducted a radio range test for two different receiver antennas.


We tested on Purdue's campus, with one team member on the 7th floor of Beering Hall (BRNG) right next to the "Vision" conference room, and me, the other team member at 11th and Tippencanoe streets in Lafayette (across the river). As you can see in the graphic, the distance is about 1.6 miles. Not quite as far as the test Eric and I conducted a couple months ago, but far enough to get some good testing done. For reference, the rated range of the NTX2 transmitter is 500m - 1.6 miles is > 2500m.

We tested a couple different antenna and found some interesting results...

I finally received the ribbon cable for my new GPS, a Lassen IQ today. I expect this GPS to be easier to integrate than the Inventek, and hopefully more reliable than the Garmin.

Unfortunately, I haven't had as much time to work on the project what with school getting in the way. However, I got a job in a machine shop which has been a lot of fun so far. As a beginners project, they had us all make so-called Turner's cubes, which is what you see in the photo. It's a fairly simple project, but it teaches you a lot of the basics. They required us to manufacture it within +/-.002 inches, which is close to the width of a human hair! I had some close calls with mine, but I managed to get everything within tolerance and looking centered. It just needs a little more polishing, but the photo above is the result of all the machining work.

I expect to integrate the Lassen IQ with the flight computer soon, and then I just need to finish up some radio antenna stuff. Finding a time to launch might be tricky since I don't think I'll be ready for the upcoming long weekend (and I plan on going skydiving that weekend anyway :P ), but I think we might just do it over a normal weekend (since there's not much other choice...). Updates will follow as I can manage.