space Archives - Castle Point Rocketry

News

Dry Run Testing

June 19, 2019June 5, 2020
by Dakota

[This is a long article. If you’d like to see just pictures and videos of our tests, check out our YouTube and Facebook pages!]

Last week, Castle Point Rocketry had two full days of testing. We verified our mechanical and avionics systems to ensure full preparation for the next round of testing: propulsion. In propulsion testing, we will light the rocket and measure the thrust it produces. It was necessary, then, that we check to make sure the test apparatus works (and can support the weight of the rocket) beforehand.

At the end of the second day, we had a fake rocket towering into the night sky.

It took all of both days, but the test was a success. We strapped a 500-pound surrogate rocket to the test stand and raised it from horizontal to vertical. In the dark!

Day One: Wednesday

We started the day by needing a U-Haul. Our lab in Griffith isn’t too far from Walker Lawn, where we were testing, but hauling a literal ton of metal up the hill sounded … none too fun. Luckily, we had some lifting help from Stevens Physical Plant and some traffic direction by Stevens Police.

Officer Gamez of the SPD posing with the team after helping us back in.

Avionics

The big focus of Day One was making sure all of our Avionics and Ground Control systems worked. To do so, we needed to take over a classroom, too. Ben found an empty room not too far away, overlooking the mechanical proceedings on Walker Lawn. Our ground control station was set up, and the wires started running!

All the wires serve three purposes: valve actuation, transducer reading, and real-time image processing. So far, the project has grown to incorporate 27 instruments. Eight of these require active actuation, and six send signals to ground control.

After double-checking that the radios worked (another important electronics test), Ben and Faris actuated each valve in the order that they will be used in testing. Though we didn’t have any temperature and pressure sensors set up, Ben also made sure the sensor code was running. Finally, we set up each of our three cameras — one real-time, one slo-mo, and one thermal — and they each came up on-screen!

Avionics Dry Run Testing: Successful.

Mechanical

Mechanical systems were being assembled throughout the avionics tests. All hands were on deck to set up the gantry hoist, test stand, and aluminum truss.

Rodrigo, Will, and Abe working on the test stand.
Will climbing the gantry hoist to adjust the winch.

These three metal structures will serve as the backbone for our propulsion testing. To restrict movement under fire, the rocket will be bolted to the 30-foot-long aluminum truss. (And tied down, twice-over.) In turn, the truss is bolted onto a short steel structure called the “test stand.” It sinks into the ground to provide added stability. In order to raise the truss, several cables run to another nearby steel structure: the “gantry hoist.” Equipped with a heavy-duty winch, it pulls the truss and rocket into place atop the test stand.

This process of raising the truss is what we tested. After a few preliminary tests and some iterative construction:

Checking calculations with a third of the truss section.
Supporting the whole truss before it goes up.

Some small edits to the gantry hoist before another pre-test. (Video has no sound.)

It went all the way up!

(Pardon Dakota’s yelling.)

By the time it came back down, it was nearing dark and threatening to rain. So we packed up and vowed to raise a weighted truss another day!

Day Two: Friday

It rained all day Thursday. Bummer. Luckily, we had the lawn reserved Friday, too. So we got back out there at 9:00am and went to work!

Step One: Check Everything

Even though everything had been set up on Wednesday, we needed to make sure everything was ship-shape. Even the slightest wiggle room on a bolt could send the whole thing crashing down. Not optimal.

Deputy Chief DiGenova of the SPD making sure our Test Stand was in peak shape.
Making sure the gantry hoist’s support cables were taut before testing.

Once happy, we jumped ahead to where we left off: Adding weight to the rocket. Our first subject? Our very own Abraham Edens.

Step Two: A Small Amount of Weight

It didn’t take much coaxing before Abe was hanging upside down. Who doesn’t want to say they’ve hung like a koala from a truss and elevated eight feet in the air?

Abe being raised to Height #1 for the first time.

To check all of our structural components, the truss first took Abe up to about six feet, then up to eight. Twice. (You can see more in the time lapse video below.) After Abe had had his fill, we gave Tom a go as well.

But all this wasn’t just eight college kids goofing off with a 30-foot truss. There was actual science behind it. Before loading up our testing equipment with 500 pounds of wood and concrete, we wanted to be sure that it could repeatedly lift human-sized cargo. And it’s a good thing we tested it out first. We were successfully able to raise both people, but the winch slowed down to a snails pace. This indicated we would need more powerful equipment for the full rocket.

Time lapse footage of both of Abe’s adventures up the truss. (Video has no sound.)

Step Three: Time to Buy Some Stuff

We took a lunch break. After all that heavy lifting (and being lifted), it was time to eat some food. We also took the chance to buy a heavy-duty winch — then the car battery to operate it.

Will and Nathan got to work installing the new winch atop our gantry hoist. Once it was up, we were all ready to go.

Step Four: Fake Rocket, Real Results

500 pounds of concrete is heavy. Our 2-ton pneumatic engine hoist was busy elevating the aluminum truss, so we lifted and moved the fake rocket by hand. Talk about a workout. Coupling the surrogate rocket to the truss required moving it ten feet to the west, then elevating it while another team member temporarily secured it with ratchet straps. Then, three linear rails permanently mounted the rocket to the truss.

But after all that grunting and sweating? We got to stand back and watch this:

Pardon the abrupt switch from landscape to portrait. (Video has no sound.)

So, there we were. Eight rocket engineers standing out on Walker Lawn at 11:45pm on a Friday night. Covered in mosquito bites, still sore from lifting a fake rocket, and getting kinda hungry again. But in front of us was solid proof that our testing structures would support the weight of our rocket.

Gazing up at the fruits of our labors at 11:45 Friday night.

In fact, the fake rocket we lifted weighs more than the rocket parts we will use in testing. The dummy rocket’s 500 pounds accounts for the weight of the entire rocket — when, in testing, we won’t be adding the fins, nose cone, or fuselage. So, really, we have a built-in Factor of Safety greater than 1.0!

Step Five: Teardown

As much as we all could have stood there for hours just gazing up at it, we took it down in a hurry. After all, it was nearing midnight and all of us were tired from two long days of testing. We packed up the U-Haul with all of our materials, leaving behind only the test stand, rocket, truss, and pneumatic hoist for Saturday morning.

Though it looks like someone landed a plane on Walker Lawn, this is what our testing apparatus looks like all wrapped up!

We found out it took even more work to take the rocket off the truss than it took to get it on. So the remaining construction was wrapped in a tarp, and we finished taking it apart the next day. And just like that? We called it a successful Dry Run Test.

News

Industry Advisor Review

June 14, 2019June 5, 2020
by Dakota

It was June 10th, 2019. A thick, foggy mist had swallowed up New York City. Hoboken traffic was, unsurprisngly, backed up half an hour. And in the back of a machine shop at Stevens Institute of Technology? Nine rocket enthusiasts were ironing out a testing procedure.

Castle Point Rocketry invited our industry advisors, Rich and Luke, in to review our final testing procedure. Somehow, there were still some introductions to be made, too!

Rich Kelly (left) and Luke Colby (right) introduce themselves before we get to work.

Luke Colby is the President and CEO of Triton Space Technologies, providing engineering design services out of Boston, Massachusetts. Luke has been advising our project by phone since Fall 2018, but we have never met in person. His company also manufactured a handful of valves that will travel aboard our rocket.

Rich Kelly is a Senior Project Engineer with Valcor Engineering, based in Springfield, New Jersey. Due to Valcor’s proximity, he has visited our lab many times over the last few months. And they also manufactured several valves we will be launching into space!

After introductions, we quickly showed Rich and Luke the latest work we had done on the rocket. Then, it was down to business.

Sitting down to hammer out the details of chemicals testing.

We crowded around an imaginary table in our makeshift conference room. (Spoiler: It’s our lab with a portable projector screen.) We had less than six hours to go through the entire 64-page Propulsion Testing Document, so… there was little time for games. (There was, however, time for lunch. Self-care is important and, as Rich reminded us, “The food’s not getting any warmer!”)

The team led Rich and Luke through our testing plan page by page, halting when there were questions or suggestions. After reviewing three tank tests, five full-stack tests, and ten procedural methods, we reached the end of our packet. We called it a day, but Luke and Rich left us with a few pointers. Among other things, the team is revising our waste management plan, redesigning the igniter (again!), and renting more robust pressure regulators.

Just some happy nerds doing space stuff.

It was then time to set our sights on the next big exciting task: Dry Run Testing!

Uncategorized

“Clean For Oxygen Use”

June 11, 2019June 5, 2020
by Dakota

We can all probably agree with the relative levels of cleanliness. Around the bottom of the scale, there’s “I Am Comfortable Living In This.” A little more clean, you probably find “Company is Coming,” closely followed by “My Parents Are In Town.” Near the top of your list, you probably find “Apartment On The Market.”

“Clean for Oxygen Use” may top the charts. It’s certainly not a household standard.

Bottom shelf: Unclean. Top shelf: Clean.

This cleaning method is the entire reason we constructed our clean room. Much of our rocket will come into contact with high-purity oxygen, whether in liquid or gas form. Gaseous oxygen loves lighting things on fire, and liquid oxygen freezes most substances solid — so we need to be sure everything is as clean as humanly possible. To do so, we have a six-step cleaning process.

Step One: Alcohol Bath

After we identify a subassembly to clean, we remove each piece from storage. We bathe each individual fitting, pipe, adapter, and valve in isopropyl alcohol. (That’s the same alcohol you put on wounds to clean them.) For 12 minutes, they rattle around inside an ultrasonic chamber. By vibrating them very, very quickly, the machine dislodges defects, dust, and other gunk that is clinging to them.

Our ultrasonic bath is located on the left.

Isopropanol is also a dehydrant. This agitation bath ensures every out-of-the-way nook and cranny is water-free. Any water left in the system would freeze in contact with cryogenic liquids, decreasing functionality and making the rocket explosion-prone.

Step Two: Nitrogen Purge

After they’re removed from the bath, each part is individually inspected for remaining debris.

A tee junction during the nitrogen drying cycle.

Then, every part is dried with a pressurized jet of filtered nitrogen. Not only does this ensure no isopropyl alcohol is left on the part, it blows away any remaining foreign materials.

Step Three: Alcohol Rinse

As if Step One weren’t enough, we then subject each component to yet another round of alcohol. This time, the isopropanol is targeted in a stream. The entire part is washed beneath a squeeze bottle before moving on to Step Four.

A tee junction having an isopropyl alcohol shower.

Step Four: Nitrogen Purge

More drying! Like most alcohols, isopropanol is flammable so we need to make sure each part is bone-dry before assembly. This last round of nitrogen is usually enough to get the last bits of stubborn junk off of our fittings.

Step Five: Critical Inspection

Once the second nitrogen blow-down is complete, we are fairly certain nothing remains. But just to be sure, though, we inspect each piece from every angle for leftovers. Inside and outside, nothing is allowed to escape our prying eyes. And on the off-chance we still find refuse holding on? We restart the whole process from scratch. We bought smaller ultrasonic bath just for that purpose.

Step Six: Assembly

Finally, we are sure that our parts are Clean for Oxygen Use. We bubbled, tossed, dried, washed, and dried most everything (and even brushed some with a high-grade pipe cleaner), and it’s time to put the pieces together. One by one, being sure not to stir the air or drop anything, the rocket starts taking shape. We have 24 subassemblies ranging in size from one component to thirteen.

One of the subassemblies we will be using for tank testing.

Each über-clean subassembly is then given a new home on the high shelf in our clean room. Small subassemblies are bagged and given a unique name so they don’t get confused down the road.

And that’s how you make a rocket Clean for Oxygen Use!

Uncategorized

Igniter Test #2

June 11, 2019June 5, 2020
by Dakota

Late last week, Castle Point Rocketry ran a successful test of our new igniter design. It is a variation on a theme (see our previous blog). This new model allows for better manufacturability and repeated use, but doesn’t sacrifice the engine-within-an-enigne design we wanted.

Many individual design components have changed over the last month. The fire now shoots down instead of up. There is a bored hole at the bottom so that the igniter can be removed from the engine quickly. We filed the top to a point so it fits into the engine more easily. Beyond that, it’s very much the same part.

Before testing.
After testing.

As you can see, we had a small meltdown problem, consistent with the last test. It’s a good thing that 3D-printed plastic parts are as printable as they are disposable!

Tom designed a gravity-driven system to quickly remove the igniter from the engine. By topping a vertical pole with the igniter, we can easily drop the assembly from the engine after ignition.

Now, we begin the process of moving forward. Our current goal is to outsource manufacturing to a local New Jersey company capable of machining it out of aluminum. That way it’s quick, close by, and made in the USA!

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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.