Friday, May 30, 2008, 07:43 PM
On May 18, the Aerospace Systems Engineering team attempted to test fire the rocket motor but had more problems with ignition.
Although the event itself was a success, the motor did not perform as expected. Based on the sensor and video data, the liquid oxygen system delivered only ~20% of the expected flowrate, although the liquid oxygen valve was open. The fuel system worked correctly, but the liquid oxygen flow was not high enough and the motor did not ignite – although the propellants did burn external to the motor (see below).
The initial theory is an ice ball formed downstream of the liquid oxygen valve and was dislodged when the main valves opened. This ice ball lodged in the main feedline or somewhere in the injector, drastically reducing liquid oxygen flow into the motor. The team has learned much from this failure and we'll try again next year.
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Sunday, November 11, 2007, 08:12 PM
Today ASA successfully test fired the rocket motor created by the Aerospace Systems Engineering team. The motor fired for 20 seconds (as planned) and produced as much as 1500 lbs of thrust.
Here is a picture of the test firing, taken from the test control area:
ASA is very proud of the team's work and wishes to thank our sponsors once again for making this possible. Additionally, the students and volunteer engineer/mentors have worked tremendously hard on this program and deserve many thanks and congratulations.
The primary goal of the ASE program was to teach engineering skills via the construction and test firing of a rocket motor, and in that we were successful. A secondary goal was to create a useful propulsion system for next year's ASE program, but unfortunately the rocket motor is not ready. A few hardware failures in the motor system prevented a full exercise of the motor's capability and therefore the motor needs to be re-tested prior to continuing the program.
The most dramatic example of one failure can be seen on the test firing video www.asa-houston.org. The nozzle blew apart at ignition resulting in reduced thrust and motor efficiency. A preliminary review of the data suggests that the motor experienced a "hard start" at ignition and the resulting pressure wave may have caused the nozzle to break. A full team review of the test data will occur soon and hopefully the cause of this failure can be determined.
Here is a still shot immediately after ignition:
Aside from these developmental issues, though, the rocket motor development and test was a great educational success and will continue to be next year.
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Saturday, September 29, 2007, 06:36 PM
ASA met today for the first time since our first attempt to test fire the rocket motor. We started the day with a complete review of the footage from the failed test firing attempts and although the failures were frustrating they are all fixable. Our failures were caused by hardware, software, and procedural issues - all of which can be fixed in the next few weeks.
After the data review, we discussed ways to improve the next test firing attempt, worked on upgrading the ignition system, and came up with a few ways to improve the LOX fill process.
We will meet 3-4 more times and then we will head out to the field to test fire the motor. Preliminarily, we will shoot for November 11.
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