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Student Spotlights

Clarissa: Chemical Engineering

Clarissa Knight is a Chemical Engineering major who had the opportunity to be a Materials and Processes Design Engineer Intern for an aerospace and defense company. Click here to read more!

What did you do for your internship?

This semester I was hired as a Materials and Process Design Engineer Intern at Orbital ATK in Promontory, Utah. In the beginning of June Orbital ATK was bought by Northrop Grumman, so I experienced working for two companies. Orbital ATK is a company in the aerospace and defense industry. There are several different programs the company works on, and the one I worked on most was the Space Launch System (SLS). This program is similar to the retired Space Shuttle with two solid rocket motors made up of five segments each. As part of the Materials and Processes group I focused mostly on two different material systems. I worked on the propellant, adhesive, insulation system inside the motors. The other area I worked was on the Thermal Protective System (TPS) which is located on the outside of the case and keeps the booster cool as it is being launched.

One of the first projects I worked on was testing the effect of an adhesive layer between the propellant and insulation. It was added to prevent off gassing of the insulation that creates voids in the propellant. Voids increases the surface area and the rate of burning of the propellant. The downside about this adhesive is that it cracks at low levels of strain, potentially causing more voids. The testing I worked on evaluated under what conditions and loads the cracks grow. I used an imaging system to track areas of high strain and then took lots of high resolution photographs and photomicrographs to evaluate crack growth. With several of the samples I measured, I noticed unusual crack growth. My hypothesis is that this cracking is not due to the loads on the sample itself, but rather the effect of the chemical reaction ozonolysis occurring on our samples. To prevent this reaction, I found that we needed purged our samples in nitrogen or argon. In another related project with this material I wrote planning to fabricate and test propellant and interphasial composite dogbones. As a solution to preventing ozonolysis from occurring on these dogbones, I incorporated a nitrogen purge to the slow rate tests.

A large part of a Materials and Processes Engineer is to write planning. I learned the programs to write the planning and wrote at least 10 plans for testing. The Engineering process begins with an engineering test plan which includes the main objectives and what will be tested. Then planning is written according to the test plan and engineering specifications to direct the operators how to perform the testing. A shop order is then issued, and operators can report their results and then engineers go back to write reports with conclusions on the testing. I participated in each part of the engineering process, but my favorite was seeing how the planning I wrote got worked by the technicians and then getting the data from my testing. I learned how vital it is to be involved with the operators especially when they are performing work for your own planning.

There are several engineering test plans with TPS materials being tested for their age life properties that I made several revisions to. This is a lengthy process that I coordinated with other design engineers, project engineers, project managers, safety, quality engineers, managers, technicians and the executing organizations. I held a meeting to discuss the changes, implemented them, and got signatures from each required organization. It was really neat to coordinate with people both on plant and at Kennedy Space Center in Florida. I learned how important it is to know all the details about the changes you want to make because there are always people who don’t want to change, and they ask tricky questions if you’re not prepared. From those revised test plans I wrote several plans to fabricate age life panels. These panels are tested at zero time, 3 years, 5 years, and 8 years to see the mechanical and chemical properties and how they change in different environments over time. From these projects I learned how the mechanical and chemical properties are interconnected. I am interested in material properties, especially the chemical properties and chemistry behind them. It was neat to see how these properties relate to the mechanical properties which I learned a lot about.

Another project I worked on started when I saw an issue with how the fines of a cork formulation dispersed in the air and the operators complained about how certain lots of material were harder to work with. The drier materials crumbled more and didn’t adhere to the outside of the segment. I wanted to test the particle size distribution to see if the amount of fines had an effect of the material properties. After coordinating with my program manager and getting the proper funds to work on this project I wrote planning and got it tested. After receiving the raw data, I analyzed it and made graphs to present the data. The data I analyzed turned out as hypothesized, with few fines in a good lot of material.

What was the most useful thing you learned from your internship?

The goals I set for my internship include not being afraid to ask lots of questions. I stretched myself and gained confidence to ask all sorts of questions. I began to be curious and wanted to learn everything I could about the processes and work at the company. I had the opportunity to go on many different tours of the different facilities on plant and I learned the most from the questions I was able to ask. At the beginning of my internship I was mostly asking questions to get familiar with the terms and acronyms used. The later part of my internship I learned to ask more in depth questions for a deeper understanding of the processes and materials. Another goal I set was to learn the most I can and apply the knowledge I have gained in school to the work I am doing. I learned so much working as an intern and had several opportunities to apply the skills I learned from my chemical engineering, math and chemistry classes. I am so appreciative for my experiences at Orbital ATK and Northrop Grumman. I learned so much that I couldn’t learn any other way and realized how much I really love working in industry!

How did your courses and your major prepare you for your internship?

An example of how I was able to use the skills and knowledge I gained from my classes at BYU started when a few technicians questioned the limits found in a material spec for a propellant curing agent believing that something was wrong with them. The maximum and minimum acceptance limits had two different values with different units. I utilized my resources and referenced older specs and found the original limits for acceptance of a material. There was a stoichiometry problem and the conversion between values were incorrect. I looked for a solution of how the error was made and found the writers of the spec did hand calculations and their twos were mistaken with sevens and threw the limits off. I then had the opportunity to contact many program representatives from many different company locations, write a change request, and hold meetings to make the change to the spec.

Would you recommend this internship to other students?

Definitely! Northrop Grumman was a fantastic company to work with. The work is intriguing and always a challenge. I learned so much and contributed a lot to the projects I worked on for the company.

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