I worked on two projects during my winter internship at Princeton Satellite Systems: a two-stage-to-orbit (TSTO) launch vehicle design proposal related to the NASA Space Launch System (SLS) and a satellite conjunction maneuver demo. These both used the Spacecraft Control Toolbox for MATLAB.
One of the main ideas behind the TSTO launch vehicle project is to propose an all-liquid variant of the SLS. Currently, the SLS first stage is mostly powered by two solid rocket boosters (SRB) upgraded from the Space Shuttle SRBs. However, our proposal is to replace the two SRBs with five liquid boosters (LB), each mated with an RS-25 engine. The second stage would remain the same. Using MATLAB, I analyzed the launch and trajectory performance of both variants and found similar performance. Additionally, the total mass of the all-liquid SLS variant would be approximately two-thirds the mass of the SRB-powered spacecraft. An approximate CAD model of the all-liquid SLS version is shown below.

In addition, the LBs can be used independently to power smaller high-performance TSTO launch vehicles that carry around 8,000 kg of payload to low earth orbit. Trajectory plots and a preliminary CAD model are shown below.
My other project this internship was to help out with a satellite conjunction avoidance demo with Ms. Stephanie Thomas. The goal was to create a solution in MATLAB to identify potential satellite-debris conjunctions and develop a method/algorithm to avoid the conjunctions. I mainly worked on testing the code and relevant functions and providing feedback about the solution’s comprehensiveness.
Overall, I greatly enjoyed this internship and the opportunity to work at PSS. I saw firsthand how even a small company can make significant contributions to aerospace and engineering through diverse interests yet specific, impressive skill sets.