Date of Graduation


Document Type


Degree Name

Bachelor of Science in Mechanical Engineering

Degree Level



Mechanical Engineering


Huang, Po-Huang Adam

Committee Member/Reader

Uche, Wejinya


Recently, engineers have been able to design smaller satellites called Nano-satellites. Nano-satellites (1-10kg) also known as “Cube Sat” are based nominally on multiples of a unit cube of 10 centimeters on each side. The basic cube shape is known as 1U CubeSat. A major obstacle when designing the nano-satellites is to choose a propulsion system that would be safe, effective, low cost, and could easily function with a resistojet. The proposed system uses Propylene Glycol (C3H8O2) as a safe propellant for a resistojet. In order to predict the behavior of the propellant, the property to be characterized is its surface tension at different concentration levels, 0 % to 99% C3H8O2. Studying the properties of the propellant will provide design parameters for the resistojet propulsion unit for a nano-satellite. In the process, a first device was built which measures two required parameters for computing the surface tension. The device measures the height and the radius of curvature of the meniscus of the liquid through a capillary tube. Experimental results were obtained for the mass concentration of the solution ranging from 0 to 40% C3H8O2 (diluted in de-ionized and filtered water, H2O). It was expected that the denser the solution was, the higher its surface tension. A second measurement system that is more accurate and has a better repeatability than the first has been completed. The system has been subjected to several testing which consist of locating and displaying the pixel location of an object that the template was programmed into the system. The freezing point of the propylene glycol was also obtained. Concentrations from 10% to 99% V/V of C3H8O2 at intervals of 10% were experimented carried out and the result show that the lowest freezing point temperature attainable by the fluid is approximately -60 °C. The data obtained were at first glance correct until the physical appearance of the experimented samples displayed a white icy precipitate.