Thursday, July 17, 2008

Rocket science

I have a little secret: I'm a rocket scientist.

OK, so maybe that's stretching the truth a little bit. I don't do ballistics calculations in my sleep, and I barely know what a Rayleigh number is, but I have worked on the 20-foot-tall BYU ARES rocket for the last three years. The rocket has a custom-built composite airframe with aluminum cross braces. It is powered by a hybrid liquid-solid rocket motor, using a ceramic nozzle manufactured by ATK—the same company that makes some of the rockets for the space shuttle.

So, how does someone like me go from being an average Joe to a contributor to a big huge rocket? My roommate initially roped me into the whole situation. He worked on the avionics system (all of the computers and electronics in the rocket), and one day while we were hiking way up in the mountains, he convinced me to join the project. I've been working on it ever since—until last month, that is.

Last month was our launch date. I flew out from California to Utah and drove out into the barren desert near Green River, where there was a university rocket competition. The goal was to get as close as possible to 10,000 feet above ground level. At least, that's what the stated goal was. Our real goal was just to launch the thing. We had all spent lots of time (hundreds of hours for me) on the project, and we really wanted to see it fly.

Since I had to fly in, I showed up a little bit late. When I got there, everyone was really glad to see me, because there were some problems with the avionics system. Matt (the other avionics guy who was there) and I got things straightened out, and we did a dry run test of the launch. Things went almost flawlessly. It was too late in the day to attempt a launch at that point, so we were going to go first thing in the morning.

The next day we showed up, fastened down the final screws, and rounded up a big crew to lift the rocket from its support cart and slide it onto the launch rail. The plan was to slide it onto the rail, raise the rail so that the rocket was vertical, fill it with fuel, and then launch the rocket.

Reality turned out to be a little bit different. As we were sliding it onto the rail, someone smelled something funny. Then someone heard a hissing sound. We stopped sliding the rocket onto the rail, and Matt frantically unfastened one of the aluminum skins that covered the avionics system in the rocket. When he got it off, he found that the batteries were self-destructing, spraying electrolyte all over and getting really hot. He disconnected them (which wasn't an easy task, since the wires were all melting together at that point), and so the situation was under control.

After three years of work and 1000's of man-hours of work, we weren't too excited about the now very real possibility that we would have to scrub the launch. It was crunch time for me to determine if we could repair the system in a few hours.

The power supply system was almost completely destroyed, melted into one big blob of plastic and metal. A fuse was blown. A power connector on the data communication radio was melted into its socket. Things smelled funny. The batteries were completely destroyed. We were out in the middle of the desert without access to an electronics store. It wasn't looking good.

I determined the absolute minimum system that we would need to launch safely: a way to open the oxidizer (liquid fuel) system valve and a way to actuate the igniters.

We tried to find batteries to borrow from other teams. We soldered a new power connection onto the radio. We bypassed a lot of the power system. After all of that, though, we discovered that our main control circuit board was fried. There was no way to control anything without that.

As we considered our options, two ideas emerged: either "hot wire" the system directly to a couple of car batteries (borrowed from our vehicles) and launch the rocket essentially as missile with no way to deploy the parachute, or scrub the launch. We talked to our faculty adviser and debated for several minutes. Many of us were graduating, and this would be our last chance to see a launch. Our faculty adviser was moving on to another project, so things were losing steam. The arguments for just lighting the fuse and running were pretty persuasive. In the end, though, our adviser decided to not launch. That was the end of the road. We packed up and went home. We had seen several other schools launch their rockets, but our own launch just barely slipped through our collective fingers.

I feel really bad about the situation, because it was my system that failed. It failed, and I feel a bit like I failed. If my system had worked, all of the time that everyone spent on the project would have been culminated in a launch. It didn't work, though, so now there's a beautiful blue rocket sitting in a lab somewhere on BYU campus, waiting to hopefully fly another day.

I'm still not sure what happened. Obviously something shorted out the batteries, but what? And why? Why did our test the day before go almost perfectly, and then why did the system short when we were loading the rocket onto the rail? I'm going to do a postmortem in the fall when I get back to school, but we may never know.

The project may be "off" right now, but I'm hopeful that the big blue rocket will fly one day. Even if it doesn't, I've enjoyed working on it, and I've learned a lot from the project.

More pictures:


tbone said...

That's the saddest story I've ever read. We should blow something up when you get back to school to make up for it.

I See Badgers said...

dang skippy! I'm up for blowing somethin' up.

ps. you disagreed with what gabe said right?

Bruce said...

I think blowing stuff up is an excellent idea. That will keep September spiced up a bit. :)

Barney Lund said...

Dude, I'm really sorry to hear it. Hopefully you'll get 'er done some other time. Blast! (double meaning)