Fail #3

The failures this summer are beginning to get comical. Sort of like a running gag. I have no explanation for this failure, but it is obviously some sort of altimeter error, or user error pertaining to the altimeter.

As you can see in the video, the drogue charge did not fire at apogee, and then the backup motor-based ejection charge did not have enough power to separate the rocket. Finally the main charge went at 500 feet and saved the rocket. There was no damage, but I still failed to get my certification because not everything went according to plan.

One note about how the rocket fell back to earth. It's interesting how, despite my nearly 4 caliber stability, the rocket flat-spun and at times appeared to be falling backwards. What's with that? I admittedly don't understand how that happens.

Video!

Pictures and Video!

I love Skidmarks.

Hybrid M-motor that never went :(

He's probably thinking "Not my day..."

From this --^

To this --^

Stinger on the pad.

June Launch Report <-- Boring Title But VERY Interesting Article

No matter what safety precautions you take, at the end of the day getting beaned on the noggin with an Aerotech Sumo coming in ballistic at a couple hundred feet per second is bad for your health. Just saying.

Despite that little incident (the victim is doing well now, but everyone was freaked out of their breeches at the time), the launch was a smashing success! (No pun intended).

First off, there was an M motor with three outboard J's that were going to airstart. The M cato'd.

Then there was a big Hypertek M motor that would fill with nitrous oxide but was having issues with the ignition system. No joy there.

Then there was my L2 certification attempt. We won't even talk about that.

Just kidding, we will. So I passed the test, no sweat. I had studied for it several times before but never got around to taking it for one reason or another. Then I got my rocket ready to fly: Stinger on a J285. I'm so brilliant. I certify L1 on an I285 which is a huge I, and certify L2 on a J285 which is a baby J. That way I can use the same rocket, same casing, same average thrust... It's amazing they even let you do it that way.

But then it came down to launch time. Despite my 4-caliber stability margin, the rocket had issues on the ascent. I'm still analyzing the video to figure out what went wrong, and I'll post it on YouTube later for you all to analyze as well. But something fishy happened. It corkscrewed a little and increased drag so much that what should have been a 5000' flight turned out to be a 1500' flight. Therefore, a 15 second delay for the motor eject was waaaay too long. The main was set to deploy at 500, but I'm not sure which deployed first, the drogue or the main. I guess I will have to look at the video and figure all these things out. But the point is that it was going way too fast when it finally ejected, and the rocket separated and I failed my certification.

Oh well.

There were some other cool things about the launch, like an L1500, and a minimum diameter H399. Mach 1.25 on the H399! But I'm too lazy to cover every launch in great detail, and besides, reading about it just isn't the same thing as actually being there.

I'm going to build a new rocket for July, so stay tuned for some build pics.

Disaster Strikes. AGAIN!!

Some days are just like that. One launch cost me almost 200 dollars in damage, because I flew every electronic payload I owned in it... and it flopped. I suppose "flopped" is a bit of an understatement. It "THUD-ed."

The really scary part is that I have to fix this rocket up in 5 days, because I have to box it up and ship it down to the State Fair grounds. I'd be chagrinned to send a half-bashed-in rocket down there... it just isn't done.

This is the second time I've had to rebuild it. I ordered a new nosecone ahead of time, just on speculation. Knowing my history, there was a fairly good chance something could go wrong, and something did:

I am still unsure of what happened, but I think that the most likely cause of this failure is that a wire disconnected on liftoff, breaking the continuity. It was hard to tell among the wreckage, since everything was in shambles.

Dangerous MALFUNCTION!

I was prepping the electronics for the next flight of my rocket yesterday, and when I attached the igniter to the electronics terminal... POOF!!! The igniter fired. Needless to say, something was malfunctioning. I checked th manual, and one thing I saw was that if you switch the battery polarity it would result in the immediate firing of any attached igniters. So I checked and triple-checked the terminals, and they were definately in the right order. So I have a puzzle on my hands.

This was a very dangerous situation. Had I stuck the igniter into the motor first, a G71 would have fired in my bedroom!

Things will probably work out, however, because the launch for today got postponed because of rain and thunderstorms, so that gives me time to order new electronics.

Disaster Strikes

I can't get over my absent-mindedness of yesterday. I'm embarrassed to even mention it, but I never even armed the timer before counting down and launching all my hard work up into the sky... It was especially embarrasing since we had some friends over to witness the flight.

One thing I have proven: fiberglass cloth really minimizes destruction to rockets caused by lawn darts. My rocket took a death-dive from over a thousand feet, and landed on the railroad tracks near the field. The nose cone was completely done-in, but there was remarkably little damage to the rest of the rocket. In fact, the fins were completely intact, all of the centering rings and internal structures were intact, and most of the body tube except for the very forward end. My construction techniques must have improved dramatically if my rocket can survive a fall from a thousand feet and land nose first on crushed rock.


So in conclusion: I have resolved to never fly a rocket again without a checklist. When people are watching me prep, waiting for the launch, my absent-mindedness gets magnified and I forget steps (very important steps!), make mistakes, and generally make a big fool of myself. So I got a good, healthy dose of humility yesterday.

Well, at least the first stage worked great!