Project HALO Status Report

Rocket Motor Test Day #5

Held on Saturday, June 17, 1995 at the HALO Rocket Motor Test Facility

The following text was taken, with permission, from an article by Ronnie Lajoie, which was published in the July-August 1995 issue of the Southeastern Space Supporter, newsletter of HAL5.

It was Saturday, June 17, and we were back for the full day of rocket testing we had missed previously.  Through the hard work of Tim, Steve, and Gene, HALO finally had its remote loading and weighing capability for the oxidizer tank.  This was greatly aided by the kind donation of a 50-pound-capable load cell from the Toroid Corporation, a local electronic parts manufacturer.  Gene had also spent some significant time organizing and labeling the electronics to make it easier to maintain.  A spare electronic signal pathway was converted for use as a telephone line, finally allowing us to talk quietly to each other between the barn control center and the test stand.

The first test went off beautifully (too bad I missed it!).  During a lunch break, Steve reported that the new loading capability worked great and that the oxidizer tank had been filled in just minutes, rather than the typical tens of minutes.  The igniter fired first time, and the asphalt motor burned well.  Larry Larsen’s data acquisition system worked great as usual and high quality data was captured and stored.  Later analysis showed that the thrust averaged 161 pounds with a specific impulse (Isp) of 177 seconds, which was lower than the 200-lb thrust and 200-sec Isp desired.

After lunch, though, events took a turn for the worse.  Our new remote loading system was unable to fill the oxidizer tank.  After much experimenting, we reached the only reasonable conclusion --- we were out of N2O --- again.  This was the second time we could not perform a test for McDonnell Douglas due to an empty oxidizer supply tank.  We immediately decided never to let this happen again.  From now on, we would always have at least one full N2O supply tank at the test site.

Hybridine Motor Fires

The day was not lost, however.  James Prentice, of Hybridine Corporation in Georgia, had brought one of his hybrid motors to test using gaseous oxygen (GOX) instead of N2O.  Since we had obtained a tank of GOX just for this occasion, that test could still proceed.  James used a piece of a solid motor for his hybrid motor igniter, which would be lit by a large squib.  James’ squib required more electrical power than the ones that we were using, so we ran an extension cord all the way from the test stand to Tim’s generator, stationed behind the barn.  Using the generator would also isolate the power surge of ignition from the data acquisition system equipment.

With all that power, the igniter lit as planned and the motor roared to life.  With a full tank of GOX to consume, the motor burned for a long time.  The flame was bright and clean, although the thrust was not as high as desired.  James was pleased with the results, and especially thanked Larry for providing some numerical data acquired during the test.  Test Day #5 ended on a happy note.

Ad Astra per Ardua -- “To the Stars by Our Own Hands”

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This file was last modified on Saturday, 15-Apr-2017 13:19:39 EDT