Project HALO (High-Altitude Lift-Off): SL-1

Post-First Attempt HAL5 Press Release (Text Version - Historical)

March 27, 1997

Primary Contact: Greg Allison
HAL5 Project HALO Program Manager
(Evening Phone: 205-859-5538)

Secondary Contact: Ronnie Lajoie
HAL5 Project HALO Logistics Coordinator
(Day Phone: 205-461-3064)

NSS Headquarters Contact: Karen Rugg
National Space Society, Washington, DC
(Day Phone: 202-543-1900)


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 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.

Testing of the electronics package is still being performed. Possible solutions include replacing the electronic timer with a mechanical one, or removing the timer, as it is merely a backup to the uplink command. A final decision is expected in about two weeks. For updates, visit the following URL:

The gondola was still on the ground when the squibs fired and at no time was there any danger of the rocket firing. The rocket launch electronics are contained on an independent circuit that has no timers. Only a coded uplink command can fire the rocket.

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.

Without the cut-down squibs, the rocket provided the only means to pop the balloon and release the gondola. About a half hour more was needed to attach new ropes to the gondola. These, added to the concerns of increasing winds and increasing air traffic, tipped the balance in favor of safety, and the first attempt was scrubbed.

The hybrid rocket oxidizer tank was drained and the rocket was repackaged for its journey back to Huntsville, Alabama. The balloon was carefully deflated (which is not easy when the plastic material is thinner than food wrap!) and repackaged as well. Because the balloon is not designed to be reused, the HALO team decided not to use it for the second rockoon attempt. Instead, the balloon will be used for further subsystem tests.

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 "" or visit:

Together we can make space history for us private citizens and help to bring about the day when we can all afford to safely travel in outer space. Ad Astra!