Blog - Page 4 of 7 - Castle Point Rocketry

What’s the big deal about the Karman Line, again?

May 7, 2019June 5, 2020
by Dakota

We do a lot of talk about “space” and the “Karman Line” in our social media and these blogs. But what does that mean? What’s the big deal?

Space is a vacuum. It’s the area above our planet’s atmosphere where there is nothing — so it’s all of the nothingness between our planet and all of the other celestial bodies. (Venus, the Sun, the asteroids, and black holes all included.)

Our solar system. Space extends much beyond this, though.

The Earth’s atmosphere isn’t pure. At various places around the globe, you can find various concentrations of essential gasses in the air. (Nitrogen, oxygen, argon, and carbon dioxide are the key players.) However, the atmosphere also changes as you travel upwards. You know when flight attendants give that speech about air masks? That’s because the air at 33,000 feet is much thinner than at sea level — the atmosphere is less dense.

A prominent Hungarian-born aerospace engineer, Theodore von Kármán, spent much of his life studying jet engines at Jet Propulsion Laboratory. He noticed that engine efficiency decreases alongside air density. At a certain point (100 km above sea level, about 62 miles), the atmosphere becomes so thin that engines simply don’t work any more.

That is the Karman Line.

A cartoon of the various sections of the Earth’s atmosphere. The Karman Line is highlighted in red.

So why does Castle Point Rocketry want to get there? Well, there’s a bit of an unofficial space race happening between colleges, at the moment. Space Enterprise at UC Berkeley has released a challenge to all other colleges: Who can get to the Karman Line (and therefore space) first?

So far, the record is held by University of Southern California — 44 km. Just under half the way there. Other key contenders are Boston University, UC San Diego, Delft University of Technology, and our very own neighbors, Princeton University.

So, Castle Point Rocketry is here to settle it. Who will be the first into space? Stevens Institute of Technology, obviously.

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Innovation Expo 2019

May 5, 2019June 5, 2020
by Dakota

This past Friday, May 3, 2019, marked the annual Stevens Institute of Technology Innovation Expo. 189 senior projects were presented by individuals and teams from all four schools at Stevens: the College of Arts and Letters, the School of Business, the School of Systems and Enterprises, and the School of Engineering and Science.

Even Stevens’ mascot, Attila, dropped by!

Castle Point Rocketry occupied a series of tables in the Griffith Building, located beneath campus on the Hudson River. Alongside many other building-intensive teams, we presented our project to students, professors, Hoboken residents, and potential investors alike.

We brought out all of our toys for show and tell.

From 10:30am to 3:00pm, members of our team rotated through presenting at the table. Notable visitors included Attila the Duck (Stevens’s mascot), Dr. Nariman Farvardin (President of Stevens), Graham Boyd (our Regional Manager for SLM Solutions), and Bob Freno (Principal Member of Engineering Staff at L3 Technologies).

Our quarter-length airframe assembly was a crowd favorite.

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Airframe Time!

May 2, 2019June 5, 2020
by Nate

Here’s the dilemma. We need the strongest, lightest skeleton possible for our rocket. The obvious choice for material is aerospace grade aluminum. (6061-T6, duh.) We also need to cut a ton of pieces, and need them done fast. The usual way to do that is with a CNC milling machine, but that can take a while and be very expensive. Also, when you cut a piece of metal with a saw or a milling machine, the metal heats up causing it to anneal and weaken. So what’s the solution?

One of the CNC waterjet cutters at New Jersey Waterjet.

Waterjet cutting is the solution!! The helpful staff at New Jersey Waterjet were able to take our CAD files and produce 30 perfectly-cut parts in just under a week.

An original drawing, fresh from our CAD software

Waterjet cutting uses a high pressure stream of water and abrasive sand to cut through nearly anything. In addition to being fast and precise, waterjet cutting actively cools the parts, preventing them from becoming annealed.

These parts will hold together the whole rocket, so it’s a good thing they’re strong.

News

Successful First Igniter Test

April 26, 2019June 5, 2020
by Dakota

As those of you who follow our Facebook and Instagram (@cprocketry) pages might know, we had an exciting night this past Monday.

After several weeks of deliberation on how to ignite, we settled upon a cocurrent jumpstart from a solid rocket motor. Imagine our large engine housing a smaller engine. The heat of combustion of the small engine ignites the rush of fuel traveling through our bigger engine and — POOF. We have lift-off.

Capturing footage of a solid rocket motor — plain, and without our igniter design.

The Theory

Combustion theory is hard. A good assumption to make, one that doesn’t need a Ph.D., is that our oxidizer and fuel will both need to be vaporized before burning. That is: They need to be a gas. This, at least, is handled by the injector.

The second part is the orientation of the starter flame. To summarize many, many studies and papers in one quick sentence: “The igniter should be oriented the same direction as fluid flow.” (Downwards.) Doing so reduces turbulence inside the engine, reducing the chances of the engine exploding. It also orients the igniter flame away from the shower-head face of the injector, which could cause some orifices to close up.

The big question, then, is how to take a solid, put it inside a liquid shower, turn it all into a gas, and light the whole thing on fire.

The Model

A few ideas came to mind. Do we hang it from a shepherd’s crook? Adhere it to the bottom of a plate? Stick it to the side of a wood pole? The problem with each of these ideas was two-fold. One: With the relatively small size of our engine, how do we ensure that these bulky geometries don’t increase the turbulence? Two: How do we take the straight flame from a solid motor and fan it out in all directions to ignite as much fuel as possible?

Luckily, a little bit of CAD helped solve all of these problems. We settled on a cylindrical igniter plug. This design allows for a variety of motors to be installed and incorporates a diverter to spread flames in all directions. (You can see the outline of our model in the video below.)

The Test

After a watching our first prototype plug print for a few hours, we couldn’t wait to test it out. Even though it was printed from polylactic acid (a plastic which melts at 220°C) and solid motors burn MUCH hotter than that, we figured we could get a few seconds of slow-motion burn time on camera.

And boy, did we get a show.

Proof of concept: The igniter plug design works!

After slowing five seconds of burn time down to several minutes, we had 10 seconds worth of good footage. You can see in the video that each of the radial flame outlets has even distribution and steady flow. Which is just what we want!

You can also tell when the melting plastic starts to disrupt the flame dispersion — about 7 seconds in. The result of that were the smoking, charred remains of our plastic igniter plug. It gave renewed meaning to the word “pungent.”

The Future

Though the test was a success, we began optimizing our design immediately. We inverted the design to allow for ease of access during testing and launch. Loading the motor from the bottom required the flame to shoot upwards, though. This, in turn, required us to reorient the flame outlets.

The team also bought several cylindrical bars of aluminum. After a successful test of our new design, we plan to machine a couple out of aluminum — which hopefully won’t be reduced to a smoky pile of ooze.

Currently, the greatest design hurdle is how to remove the igniter from the engine during testing. Since the rocket is attached to the ground and the current igniter design doesn’t move, we’re back to square one — disrupted Mach flow in the engine. (A result of turbulence.) Luckily, we’ve got a crack team of young rocket scientists working on it.

So that’s where we stand! Proof of concept confirmed, future planned out, and a moveable design in the works. Just in time for our rapidly-approaching testing timeline.

News

techdrawer interview released!

April 20, 2019June 5, 2020
by Dakota

You may remember that, a few weeks back, the YouTuber ‘techdrawer‘ paid us a visit. We spent the better part of an afternoon in front of the camera for an interview, followed by a quick tour of the lab. Over the past few weeks, all of the raw footage has been whittled down into a coherent interview.

On the morning of 19 April, techdrawer dropped the finished video!

The finished video — all 16 minutes of it!

Sergio, the face of techdrawer, did a great job of leading the team in an informative discussion about or project. Topics covered include our motivation, what we hope comes of the project, and brief explorations of the science behind it all.

We hope you learn a little something about our team over the course of the video. If you do, don’t forget to give it a like! With your help, two Stevens student groups (techdrawer and Castle Point Rocketry) will benefit!

News

Ready, Set… Launch Stand!

April 3, 2019June 5, 2020
by Dakota

A few weeks ago, we shared how excited we were about our truss being delivered. Now, the fun of building it.

Throughout our interview with techdrawer this past Saturday, Nathan was hard at work assembling the launch stand that our truss will stand on. When our day with techdrawer came to a close, he convinced Dakota and Ben to run through the hoisting process with him.

You can see the launch stand in the photo below to the right of the blur-that-is-Nathan. It’s rectangular and made of steel.

Behind the Griffith Building preparing to hoist the truss onto the launch stand.

The hoisting process involved several meters of cable, two steel structures, nineteen cinder blocks, three humans, one ladder, and three three-meter lengths of aluminum truss.

After bolting the lengths of truss together, we lifted it with an engine hoist and attempted to lever it up with cables and pulleys. The first attempt didn’t go so well. The truss ended up balanced on Dakota’s head while Ben, up the ladder, steadied it and Nathan retied it to the hoist with a complicated series of climbing knots

The final product. Excited Nathan, to boot.

72 hours later, CPR tried once again. We had a modified launch stand, two more Mechanical Engineering majors, and better lighting to help this time. And were we successful? Well, Nathan’s smile in the picture above should answer that!

News

techdrawer visits CPR’s lab!

April 3, 2019June 5, 2020
by Dakota

A few months back, the team received an e-mail from Stevens’ very own YouTuber ‘techdrawer.’ Their interest in the team’s motivation, conception, and progress was contagious, so we invited them over to our lab for an interview.

Due to timing difficulties and postponed deliveries, that invitation finally came to fruition this past weekend.

Members of both teams, CPR and techdrawer, pose for a picture after filming.

Around noon, we descended on Stevens’ Griffith Building, where Castle Point Rocketry has built many of the components of our rocket. While techdrawer got set up — lights, cameras, the works — members of CPR finished up with a few pet projects. Nathan worked on building our test stand. Ben kept coding the flight computer. Dakota did more simulations on the injector.

When techdrawer was ready to go, we sat down to talk.

A behind-the-scenes shot of Sergio, the face behind techdrawer. The final interview will be available on their YouTube channel.

With the exception of a long lunch, CPR was on camera for most of the afternoon. In the official interview portion, Nathan, Ben, and Dakota answered Sergio’s questions to the best of their abilities. After, techdrawer went mobile for a tour of our lab. Among other things, Monica went over the logistics of our fuel tank and Thomas went into further detail on our engine.

By the time 6:00pm rolled around, we ran low on new topics. (techdrawer was also running out of storage space!) We called it a day, and techdrawer went home to splice together a video! CPR stayed behind to build a launch stand…

Keep your eyes on techdrawer’s channel and CPR’s Facebook page for the finished product!

News

Ground Support to Major Tom

March 25, 2019June 5, 2020
by Nate

The centerpiece of our ground support equipment arrived today via ground freight. 9 meters of aluminum triangle truss from the Prolyte Group.

The truss will be used as the primary support for our rocket’s launch rail. Once completed, the launch stand will measure just over 10 meters tall. The rocket will slide on studs that slot into the launch rail, which will in turn be mounted to this truss.

Our full truss section, traffic cone for scale

As more and more major components of our project arrive on campus, the excitement grows. Things are becoming very tangible — in only a short time, we’ll have a fully-assembled rocket to blog about!

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The Hunt for the Best Igniter

March 14, 2019June 5, 2020
by Dakota

So, rockets burn fuel. That much makes sense. And that combustion of cold liquid creates a lot of hot, pressurized gas that makes the rocket go upwards. Got it. But how does that begin?

You can’t light a kitchen stove without the internal igniter sparking. In the forest, you can’t start a campfire without flint and steel. (Or lighter fluid and a barbecue lighter.) But inside a rocket engine… things are a little more complicated. Castle Point Rocketry has been upending shelves worth of books (all online, don’t worry) searching for the question on the forefront of our minds: “How do we start our engines?” And we’ve narrowed it down to three major contestants.

“The Cotton Ball”

Soak a cotton ball (or other highly-porous material) in something really flammable.
Stick said drenched cotton ball on the end of a metal stick.
Set rocket over stick, with cotton ball inside combustion chamber.
Light cotton ball on fire.
Release the fuel and LOX.

Proof of concept: It’s been done before.

Potential drawbacks include the sudden onslaught of liquid, though flammable, extinguishing the burning cotton ball.

“The Salt Crystal”

Finish researching oxidizing rock salts. Some salts, when heated, spontaneously burst into flames and release copious amounts of oxygen — which helps fuel more decomposition.
Acquire a small-ish amount of the chosen salt.
Carefully pack the salt into a small container on the end of a large stick.
Gently place the rocket over the stick, with salt container inside the engine.
Warm the container and wait for sparks, then release the fuel and LOX.

A snippet of molten oxidizing salt shooting flames.. (1:55 – 2:10.)

Potential drawbacks include the risk of salt decomposing before the igniter set-up is prepared.

“Engine-ception”

Now imagine, if you will, an engine inside an engine.

Source a suitable solid rocket motor, given its thrust/time curve.
Semi-permanently affix the motor to the bottom face of the injector.
Ignite the solid rocket motor.
Release the fuel and LOX.

Solid rocket motors produce a very well-regulated flame over a set period of time. Additionally, this set-up allows both flames (from the starter and the combustion) to travel in the same direction. By doing so, we can reduce the chance of the starter blowing out!