Test firing

On January 20, 1963, under a clear blue sky, the first shot was fired. A 694-pound [315-kilogram] wooden slug was propelled over 1.8 miles [3,000 meters] into the air, flying for 58 seconds before landing about a half mile [one kilometer] off-shore. It was a complete success, so two further scheduled test firings were abandoned, and preparations were made to fire real projectiles.

Project HARP’s 16-inch gun firing into the sky. Public domain.

The next day, a Martlet-1 was launched. The Martlet was a dart-like, finned projectile named after the mythical bird on the McGill University crest. It flew far higher — to an altitude of 16 miles [26 kilometers] with a flight time of 145 seconds.

Two days later, a second Martlet-1 reached 16.8 miles [27 kilometers] with a radio transmitter beacon attached. This allowed the team to track the projectile throughout the course of its flight.

But the first tests revealed a few problems — the decades-old gunpowder being used to fire the gun was of poor quality, and the projectile was leaving the barrel so quickly that the gunpowder didn’t have time to completely burn. The powder was replaced, and by the end of June a world-record altitude had been reached of just over 57 miles [92 kilometers] for a gun-launched projectile.

It wasn’t just for fun. The Martlet was equipped with electronics that released chemical markers at set altitudes, leaving a smoke trail through the sky that could be used to measure upper-level winds. Some used additional electronics to measure magnetic fields. Bull later wrote:

The idea was to find out what happens in the atmosphere from sunset to sunrise. Remember, nobody gave us grants. We had to produce tropical atmospheric meteorological [data] for the army research office, that’s how we got our money. We were trying to measure everything to the top of the atmosphere, which we labeled as a nominal two hundred kilometers.

Funding was increased, but this high-atmosphere work was only an appetizer for Bull’s real interests. He wanted to fire a projectile into space. After extending the gun, allowing the powder to be contained for a longer period of time and slowing the acceleration, the team managed it. On November 18, 1966, a Martlet-2 was launched just short of 112 miles [180 kilometers] high — a world record for a gun-launched projectile that remains to this day.

The speed of the projectile was less than half of that necessary to reach low Earth orbit, so Bull wanted to continue. He designed a more complex Martlet-3 and Martlet-4, which were miniature rockets with their own thrusters. But political opposition to the project was mounting — the U.S. Army lost its battle to control space operations and was forbidden to conduct launches above 62 miles [100 kilometers], meaning that all funding for Bull’s orbital program had to come from the Canadian government.

That budget was shrinking due to changing public attitudes toward military affairs, and negative reviews from the press and other researchers. A change of government sealed the deal — Canada didn’t renew its funding in 1967, despite a last-ditch attempt to stir some nationalism with a plan to launch a Canadian flag into orbit.

With the cancellation of Canadian sponsorship, and the U.S. Army’s inability to launch to orbit, Project HARP was over.