A combination of an electrical problem, increasing winds, and increasing air traffic resulted in a scrub of the first attempt to launch the Project HALO Space Launch 1 rockoon on Saturday, March 22. With winds forecasted to be breezier on March 23, the Project HALO team decided to scrub for the weekend and to try again at a later date. The group has tentatively selected May as the month for the second attempt.
The electrical problem has been traced to a electronic timer in the gondola electronics package - part of the backup safety system for the rockoon. The timer, which was to have triggered seven hours after switching to internal battery power, instead triggered less than ten minutes later. The most probable cause was radio interference from an ATV (amateur television) transmitter.
The backup safety system is designed to enable release of the gondola from the balloon in case the balloon drifts off course or the rocket does not fire. (The primary means to release the gondola is for the rocket to launch right through the balloon.) Once released, the gondola would fall and pull on two cords. One cord would deploy the gondola parachute. The other cord would pull open a "tear-out panel" on one side of the balloon, which would allow helium to escape and the balloon to float back to the earth.
The gondola release system is composed of two "cut-down squibs" attached to ropes on either side of the gondola. The cut-down squibs are fired in a pre-programmed sequence triggered either by a coded uplink command or by the backup timer. Despite the timer problem, the sequence did proceed as programmed and both cut-down squibs successfully cut through their ropes. A minute later, as programmed, two other cut-down squibs attached to the tear-out panel cord also fired successfully.
The squibs fired at about 7:20 AM. The Project HALO team was slightly behind schedule due to this being their first nighttime operation. The FAA had been called and had agreed to extend the launch window from 6:30 AM to 7:30; but they warned that air traffic would be increasing after that. The large plastic helium balloon was inflated and ready to carry the rocket and gondola to 90,000 feet. The SL-1 rocket was fueled and ready for its historic mission to become the first amateur rocket, and the first hybrid rocket, to reach space. Winds had increased overnight, however, and were beginning to become breezy, so the launch was scrubbed.
The Huntsville Alabama L5 Society (HAL5), a chapter of the grassroots National Space Society (NSS), has spent the past two years developing and testing components for a "rockoon". A rockoon is a rocket that is launched from a high altitude balloon. The rockoon approach allows a small rocket to obtain a very high altitude because there is little air to slow it down during launch. Rockoons were first flown by James Van Allen in the 1950's as part of a joint Navy/university project, but were abandoned when sufficiently large ground-based sounding rockets became available.
HAL5 has updated the rockoon concept using 1990's amateur rocketry and electronics technology. HAL5's goal is to make space more affordable for students, amateurs, experimenters, and researchers. The HAL5 program, started in July of 1994, is called Project HALO, for High Altitude Lift-Off.
The HALO rocket utilizes hybrid propulsion, whereby an inert solid fuel is kept safely away from a liquid oxidizer until the rocket is ignited. The solid fuel used for the HALO rocket is pure asphalt, the same material used on streets and roofs. The liquid oxidizer used for the rocket is nitrous-oxide, the same "laughing gas" used by dentists. After constructing their own rocket motor test facility in early 1995, HAL5 has since performed over 50 static firings of its hybrid rocket motors. HAL5 successfully launched a test hybrid rocket from the ground in Manchester, Tennessee in April of 1996.
Due to limitations of recovery boats, the balloon was to be launched inland, from a farm in Cerro Gordo, North Carolina (about 60 miles west of Wilmington). March winds would have carried the balloon ESE as it rises to 90,000 feet. The command to launch the rocket would be sent only once the balloon is safely over open ocean and the rocket pointed away from land.
Floating in the frigid stratosphere, the balloon will be brittle enough to "pop" when the HALO rocket safely shoots through it. HAL5 successfully launched a smaller 19,000 cu. ft. capacity plastic balloon from Huntsville, Alabama in September of 1996. HAL5 also has successfully sent six smaller latex rubber balloons to the edge of space, which have carried both rocket test parts, electronics, and student experiments.
The second rockoon attempt has been tentatively scheduled for May, contingent upon resolving the electrical problem and on raising sufficient money. About $5,000 is needed to cover some remaining expenses for the first attempt and to cover the second. Donations from private individuals are more than welcome and would be very much appreciated. For more information, send E-mail to hal5@iquest.com or visit: http://iquest.com/~hal5/HALO/
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