Saturday, December 9, 2006, 06:46 PM
Today was the last major work day of 2006, due to the upcoming holidays. We will start up again on the first Saturday in January, when we will move into our testing facility.
This week, we finished installing the fuel system plumbing continued working on the liquid oxygen system plumbing, and planned out the ablative combustion test series. The only major items remaining on the liquid oxygen system are: tapping a hole for the motor purge line inlet port, flaring two main oxygen lines, and installing a helium regulator - we are almost ready to start water flow testing!
In addition to working on plumbing, the students worked with Nichole and Amanda to design a device to burn ablative test samples (fibers and resin) while measuring the wall temperature on the back side of the test sample with a thermocouple sensor. This testing will help determine how well the rocket motor's ablative liner will protect the wall of the combustion chamber.
The following two pictures show the fire side and temperature sensor side of a representative sample of ablative material. This particular sample was a composite of fiberglass and polyester resin, and was used by the students to design the combustion test apparatus which they will use in January. This sample performed as expected - the fire side burned and the resin boiled while the temperature sensor side remained relatively cool (although some soot deposited on the back side).
Burned side:
Unburned side:
While this type of testing cannot be compared to the actual rocket motor combustion chamber conditions (>4000 deg and > 200psi), it will allow the students to determine what type of ablative materials will work better than others.
Our next work session will occur in January, when we will begin burning the composite test samples, pressure testing the rocket motor plumbing, and eventually testing the complete plumbing system with water and then liquid nitrogen.
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Saturday, December 2, 2006, 05:26 PM
After a break for Thanksgiving, the ASA is back at work.
During today's work session the propulsion team installed the liquid oxygen valves into the rocket motor plumbing. Three liquid oxygen valves were donated to the ASE program by Sierra Lobo Inc. and NASA/Kennedy Space Center and we are very grateful for their crucial donation. With the inclusion of the LO2 valves, the rocket motor plumbing assembly is nearly complete. In the following picture of the main valve assembly you can see the two main valves (#1, LO2 and alcohol), the main valve actuator (#2), the pneumatic override piston (#3), the purge system (#4), the pneumatic control manifold (#5), and the back side of the rocket motor injector (#6):
The last few tubing items were also fabricated this week, involving a lot of hand labor. In this picture, a purge line is being bent into the correct shape using a tube bending spring and a mandrel:
The computer team has been invading our work area repeatedly over the last few work sessions installing the computer control system onto the rocket motor plumbing - such as in the following picture, where the computer team is working out an issue with sensor wiring:
In addition to plumbing work, the team also continued producing composite test samples for the upcoming combustion test series. Nichole, Julien, and Jewell spent many hours on Saturday making lots of samples using the vacuum sealing machine using various types of fiberglass and resin:
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Saturday, November 18, 2006, 04:35 PM
Today the propulsion team wrapped up a few remaining plumbing items like repositioning the purge solenoid, bending the steel tubing for the ignitor and combustion chamber pressure sensor, and making room on the tank stand for a fuel tank relief valve:
Later in the work day, Nichole and Amanda walked the students though the process of making composite test panels. Over the next few meetings, the team will be making many different test samples using various fibrous materials and resins in order to find the best combination of fiber and resin to resist heat in the combustion chamber of the rocket motor. After these test panels are cured, we will test the samples by burning the top side of the test sample with a torch while measuring the temperature of the bottom side of test sample using a high temperature thermocouple. This series of tests will show which type of fiber/resin combination is most resistant to heat and will therefore do the best job of protecting the walls of the rocket combustion chamber when the rocket motor is operating.
Here is a picture of a student applying resin to test sample #3:
The test samples were wetted with a predetermined quantity of resin, applied to plexiglas backing material, and then vacuum sealed in a food-grade vacuum sealing machine to increase the density of the finished product:
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