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

Third Attempt: Post-Attempt HAL5 Press Release (Text Version - Historical)

May 19, 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)


At 8:25 AM EDT, on a record cold Mother's Day morning on Sunday, May 11, a small group of space enthusiasts made amateur rocketry history by launching the first amateur rocket from a high altitude balloon, a concept known as a "rockoon". The group, the Huntsville Alabama L5 Society (HAL5), a chapter of the grassroots National Space Society (NSS), also made history for "professional" hybrid rocketry by becoming the first group of any kind to launch a hybrid rocket from high altitude. The balloon was launched from a coastal site in North Carolina, staying true to the state's motto of "First in Flight".

With an estimated apogee altitude between 30 and 36 nautical miles for the rocket, HAL5 now holds claim to the world record for the highest altitude achieved by an amateur rocket, and also by a hybrid rocket. The previous record for an amateur rocket was about 100,000 feet set by a group from Vermont (or perhaps 66,000 feet set by Ky Michaelson). The previous record for a hybrid rocket was set on January 8, when a NASA-industry team sent a nitrous-oxide and HTPB-rubber hybrid sounding rocket from the ground to 119,780 feet. An apogee altitude of 36 nautical miles is 14 short of the US-defined space border, thus HAL5 has yet to achieve its secondary goal of getting the first amateur rocket into space.

HAL5 had spent the past three years developing and testing components for its "rockoon", which 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.

A rocket launched at 100,000 feet is above 99% of the atmosphere; therefore it is subjected to only 1% of the drag that a similar ground based launch would experience. A rocket launched at high altitude can also operate much more efficiently, because there is less back pressure on the nozzle exit to oppose the rocket thrust. This translates to a higher thrust for a given amount of fuel consumed per second, a term in rocketry known as “specific impulse”. In lay terms it is analogous to a car’s miles per gallon.

Rockoons were first flown by James Van Allen in the 1950's. 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.

The HALO Space Launch 1 rocket was launched at 60,000 feet from a large high-altitude helium balloon made of clear polyethylene plastic over 100 feet long, but thinner than a sandwich bag (only 0.35 mils thick). At its design altitude of about 130,000 feet, the balloon, which has a volumetric capacity of 141,000 cubic-feet, would have expanded to 65 feet in diameter.

Due to concerns about the weather for early Saturday, May 10, and given FAA approval for Monday, HAL5 had decided to delay the second attempt of Space Launch 1 until Sunday, May 11. It was worth the wait. Sunday morning was perfectly calm, albeit cold, and the balloon launch could not have been better. "Picture perfect" as photographs published in the Wilmington Morning Star will attest. A slight delay caused by some empty helium bottles resulted in a launch at 6:59 AM EDT. The FAA had graciously allowed us to extend our window until 7:05 AM.

Wind carried the balloon from its launchpoint in Hampstead, North Carolina (about 20 miles north of Wilmington) about 110 nautical miles to the east as it rose at an increasing ascent rate from 600 to 700 feet per minute. At the time of the rocket launch at 8:25 AM, the balloon was safely over open ocean and well away from land.

The balloon gondola carried an amateur television (ATV) camera and transmitted live color video back to earth at a frequency of 434 Mhz. The camera was oriented so that it looked straight up past the side of the gondola towards the balloon. The rocket carried a smaller black and white ATV camera transmitting at 1280 MHz, GPS receiver, and transmitter.

At 8:25 AM, the balloon was at about 60,000 feet altitude when it suddenly opened along a seam line. This was not supposed to happen, even at altitude, as the bottom of the balloon is open to allow helium to vent when necessary. We are still analyzing the video to determine what happened and will be sending a copy to the balloon manufacturer to get their expert advise. With the rocket well clear of land, and well out over international waters, a decision was quickly made to send the command to fire the rocket.

Gondola video was fine throughout the mission and clearly showed the rocket launching past the deflated balloon -- confirming a near vertical launch for the rocket as planned. The color video shows a brillant flash from the rocket exhaust followed by an expanding cloud of plastic bits leftover from the plastic wrap. The rest of the gondola appeared intact. The cut-down squibs were fired by remote command shortly afterwards to release the gondola from the balloon and to deploy the gondola parachute.

Altitude verification for the rocket was to be primarily based on signals from an onboard GPS receiver. GPS transmissions faded away, however, while the balloon was only at 30,000 feet. Backup altitude verification was to have come from the B&W camera, which was oriented so that the curvature of the Earth can be measured to estimate the altitude. The rocket video transmissions lasted longer, but also faded away before the rocket reached apogee. The team is confident that the onboard electronics operated properly, but the antennas used were not oriented well or large enough for the signal to reach out past 100 miles.

The balloon was estimated to be between 53,000 and 60,000 feet high when the rocket was launched. Computer simulations of the rocket for a near vertical flight then predict an apogee altitude between 30 and 36 nautical miles. Analysis of available data and video is still being performed to determine the altitude and distance reached. Without the GPS transmission, HAL5 has no direct measure of rocket apogee altitude. HAL5 would be most grateful to anyone tracking the balloon and/or rocket by radar, by radio transmissions, or with optical telescopes to send us a copy of your data and conclusions.

The balloon gondola and rocket both splashed down far out in the Atlantic Ocean, well out of reach of our recovery boat. It is possible that they will wash up on shore some day in some country. Rewards and acknowledgment will go to whomever recovers the balloon gondola and/or rocket. If you find either one, please take photographs and make notes of its condition where you find it (on the beach or in the ocean) before picking it up.

The entire Project HALO team deserves our heartiest congratulations for a job very well done! They definitely proved how "professional" an "amateur" organization can be. The standard has now been established and the foundation of the pathway for amateur access to space has been laid -- with asphalt!

HAL5 would like to thank the many members of its Project HALO team, including its temporary on-site volunteers, for successfully conducting this enormous volunteer effort. We would also like to thank the entire memberships of HAL5 and NSS for their support for the last three years. We would also like to thank the people of Hampstead, Topsail, Wilmington, Rocky Mount, Cerro Gordo, and Whiteville, North Carolina for their fine hospitality, encouragement, and support during this mission and the during the previous attempt on March 22, especially landowners Benny Godwin and Cary Bruton.

Finally, HAL5 would like to thank the members of the press who came out on very cold mornings to help spread the word about our history making endeavor, and for understanding the nature of technical and weather delays.

For more details, please see the following HALO web site at:

This information can also be requested by sending an E-mail message to "" or by calling one of the contacts listed. Press Kits are still available on the Web site in various formats.