Back to Work

Okay... So I just have to pull through three weeks of studying and taking final exams. Then it's home again for another three weeks.

I have to work hard now. I've got so much going on at once: Chemistry test; long, drawn out calculus homework; coming up with money to stay in school; very difficult FORTRAN program that does what RockSim does but not half as glamorously... you get the picture.

Concerning NaNoWriMo: I reached the 50,000 word mark the day before Thanksgiving, but my story is far from complete... Maybe I'll pick it up again over Christmas break.

My next USLI meeting will be this Thursday. Things are starting to pick up, so stay tuned for a post on our progress. We submitted our preliminary design review to NASA the day before break, so we should expect some feedback soon. ISU-USLI's website can be found at this address: http://www.isu-usli.com/

Very fun.

The Results...

The first official flight should have been REALLY SUPER GOOD. We had a 47 second flight time, but our altimeter reported an unrealistic 270 feet. It was a beautiful flight, and had our atimeter worked properly, we would've started packing for D.C. But it didn't. The officiator is going to contact Trip Barber of the NAR to see if we can get a re-do flight for that one. I hope we do, but if not, we can be proud of the good job we did.

The second flight wasn't as good, but at least the altimeter worked. We only got 681 feet, so the flight time was only 33 seconds, disqualifying us for that flight. Also, the streamer dropped like a rock, which is unexplainable since it was exactly the same streamer.

We're hoping for a re-do flight for a chance to prove ourselves! Go Andover!

From left: Me, Sam, Phil, Matt

Me, climbing the tree to get the egg capsule/altimeter down.

Rocket Team at work

Me and my family are going out of town over spring break. We're driving all the way down to Florida to visit a college, Embry-Riddle Aeronautical University, where I hope to enroll in the fall as an aerospace engineering student. It's going to be a very informative visit.

We happen to be down there at the same time NASA will be launching its fourth to last shuttle flight ever, April 5th. Since I've never seen a shuttle launch in person before, I never will unless I do on this trip. NASA is retiring the shuttle this year.

If I'm not able to blog on the trip, expect an exciting post filled with adventures on April 7th!

Don't Hold Your Breath, But We're Getting Close!

Monday is the day. Tomorrow is our official flight. If we're in the top 100, we go to Nationals in D.C. If not, we just pat each other on the back and say, "Well, it was fun anyway."

So far our best altitude was 810 ft. and our best flight time was 51 seconds. (We had a 36 second flight but more points are taken off for being under 40 seconds than over 45, if that makes any sense at all. That's probably because it's harder to make the rocket descend slower with a streamer than faster). Now if our rocket can just behave itself for the official flight, we'd be in good shape!

Hmmmmmmm...

We're getting some interesting results. The first flight was ridiculous.We forgot to drill a hole in the body tube for the altimeter to sense pressure changes, so it told us something ridiculous like 350 ft. The second flight was even ridiculouser. The altimeter gave us a whopping 170 ft. After a thorough inspection, it turned out that SOMEBODY drilled the hole in the wrong end of the body tube, the recovery bay end. That was promptly fixed, and then, after the third flight, we check the altimeter and it's telling us 1621 ft. Are we supposed to believe that, after the junk it's been giving us? Perhaps we're doing something wrong. Well, either way we're doing something wrong, and we have a deadline staring us in the face. AHHHHHH!!! Everybody panic!!!

Newly Refurbished

Yes, it looks like we're going to be able to pull it off after all. I'm working on a new payload bay that will be able to hold a much bigger recovery device, and some meatier F's are in the mail right now. We should be cooking with Crisco when we get it all put together. Maybe we'll even make it to Nationals!

Rocket Science is Fun!

A Slick Paint Job

We got to use the resources of the tech-ed department to paint the rocket. We only spent about three hours total on it, which wasn't enough priming and sanding to remove the spiral from the phenolic airframe, but the end result was still pretty good. We used black and gold, the school colors. Its black with a double gold spiral from nose to aft. Silly me, though. I seem to have left my camera at school! Come back on Monday and I'll have some great pictures.

Here's the solution to #4 on my pop quiz:

Sound intensity I = P/(4*pi*r^2), P is power and r is the sound distance from the source. In this case, r = d.

Apparently the actual sound intensity didn't matter because they gave us I and 1/3I. So I plugged some random number like 1 in for I. I₁ = 1 W/m^2 and I₂ = .333 W/m^2. Rearanging the intensity equation for power is P = 4*pi*d^2*I. d₁ = 562 meters. P = 4*pi*562^2*1 = 3.97x10^6 W. I then solved the intensity equation for d so I could find d₂. d = (P/(4*pi*I))^(1/2). Plugging 3.97x10^6 in for P and .333 in for I you get 973.4 meters. Once you have this, you can use the kinematic equation d = 1/2at^2 to find t₁ and t₂. Solving for t you get t = (2d/a)^(1/2). t₁ = 5.79 seconds and t₂ = 4.40 seconds. The change in time from the first sound emmission to the second is t = t₁ - t₂ = 1.39 seconds. But this isn't the final answer, because the question asks for the time between each of the measurements below at the ground-based monitoring station. Sound takes time to travel through the air, so you have to find the amount of time each sound wave took to go from the altitude they were emitted at and the station. t = d/v, so t₃ = 562m/343m/s = 1.64 seconds, t₄ = 973m/343m/s = 2.84 seconds. So to find the time between the two measurements you just have to sit there and think about it for a while, and finally you come up with t = 2.84 sec + 1.39 sec - 1.64 sec = 2.59 seconds

I thought that was a fun problem.

Hey, I Know How High It Went!

I figured there's got to be a way to calculate the altitude effectively. I thought it might have something to do with the descent, since the factors are more controlled than on the ascent (variable thrust hence variable velocity hence variable drag hence calculus). The answer was terminal velocity. Solve the drag equation for velocity, and call the drag mass x gravity since the rocket is in equilibrium. The result is the following equation:

v = [(2mg)/(pACd)]^(1/2)  (I hate typing math. It always looks like someone just puked jibberish)

where v = velocity, m = mass of the rocket (0.550 kg), g = gravitational acceleration (9.8 m/s/s), p = the atmospheric density (1.2 kg/m^3 at the time), A = the area of the parachute (0.164 m^2), and Cd = the drag coefficient for our parachute (0.75 for a flat sheet). Plugging it all in yields v = 8.54 m/s.

I then went back to the video and timed the descent, which turned out to be 21 seconds. Using d = vt I was able to figure the rocket fell from 179 m, or 574 ft.

It is important to realize that this wasn't the maximum altitude the rocket reached, it was simply the point where the parachute popped out. The rocket may have fallen from a hundred or so feet beyond that.

If anyone finds a problem with any of my thinking, please let me know.

Figure 1

Forces of drag and gravity are in equilibrium (Net force = 0)

First Test Launch!

We just conducted our first two test launches of our TARC entry. We have been really pushing ourselves to get ahead of schedule so that we can fit in as many test launches as possible before the official ones this spring. The snow on the ground complicates things just a little, but it actually saved our rocket. The first launch went well on the ascent (the easy part), but when the 24-inch plastic parachute came out it ripped right off and drifted away. The rocket came tumbling down in fifteen seconds and buried itself in the snow. Had there been no snow, the collision would have resulted in some serious damage.

So we ran back to the physics room and grabbed our spare chute. This was a heavy-duty ripstop nylon one, whose shroud lines were stitched right into the canopy. It wasn't about to fail anytime soon, but it was considerably smaller, hence our flight time was still only thirty seconds--ten short of the forty-second parameter. However, the flight was absolutely spectacular.

There isn't any altitude data yet since we are still waiting on our altimeter. Some people tried measuring an angle, but a hundred feet isn't much of a baseline...

Suprisingly our egg survived! After its harrowing first flight we took it out to examine it. Just a few hairline fractures in the shell, but it was still alive! We placed it back in its well-padded cockpit for the next flight, which went beautifully. Our egg survived a flight with fractures in its shell!

Here it is!!

Team Name?

I'm going to bring it up next meeting, but I think we need a creative name for our team. If anyone comes up with any good ideas until then, don't hesitate to leave a comment. The same goes with our beautiful nameless feat of engineering.

Looking forward to a new semester! Thank heavens I have NO humanities courses, just pure math and science.

Celebrating 100 Posts of Blogging Excellence

Happy 100th-post-reading!

Our progress in rocket team has come to a stand still until we can obtain a few supplies. I'm not in the middle of any other projects right now, and all I am doing these days is learning calculus, physics, chemistry, and some topics in trigonometry that wasn't even covered in class. I'm not even in a class for chemistry, I'm trying to learn as much of it as I can on my own because I'm taking an SAT subject test in December. Somebody's not going to have a life..." as my former chemistry teacher put it. And oh boy is he right.

So if I don't post anything for a week, you'll know why.

Rocket Team Update

Our rocket team at school has been making some great progress in preparation for Team America Rocketry Challenge (TARC) 2010! We "finalized" our RockSim design, and are now going to start collecting parts. I made a fiberglass transition piece this afternoon, and considering that I always have trouble with the fiberglass and epoxy getting everywhere, I think it turned out rather nicely. One of the kids' (there are four of us, three freshmen and me), grandpa has a lathe, and he's going to see about making a few balsa nosecones for our project.

As we build it I'll be sure to post pictures of its progress. I've also been getting goofy doing mini research papers on the durability of certain types of eggs. I'm very fortunate to have three kinds of chickens at my disposal.

Rocket Team

An amazing new opportunity has come my way: My physics teacher, Mr. Shaffer, is the leader of a small club at my school called the "Rocket Team." The goal of the club every year is to build an egg-lofting rocket to enter in the Team America Rocketry Challenge contest. Every year the rules for the contest are slightly different. This year, we launch an egg to 850 ft and have a total flight time of 40 seconds. Any differences in altitude or time aloft give you points. You don't want points.

And here's the best part about it: if you score in the top 100, you advance to nationals in Washington D. C.! The winners of the national event each receive $10,000 scholarships. This is definately worth some time and energy. A cool thing about nationals is that a lot of head aerospace companies and defense people are there. You could very well just walk into the crowd and start talking to the CEO of Lockheed-Martin. Some great connections can be made there, needless to say.

I hope we do well! No matter what though, it will be a great experience.