High Altitude Research Project

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The 16-inch HARP cannon was shot down in Barbados
Rest of the project in Barbados (2010)

The High Altitude Research Project ( HARP ) was a project carried out from 1961 to 1967 to research the ballistics of re-entry objects that were shot at great heights with a cannon and rocket propulsion . In the early 1990s there was an American continuation of HARP high-speed cannon research under the name Super High Altitude Research Project ( SHARP ) at the Lawrence Livermore National Laboratory .

HARP

idea

The idea behind the HARP project is that of the space cannon, which goes back to a vision by Jules Verne in the novel From Earth to the Moon . The aim of this ballistic transport option is to be able to bring acceleration-resistant cargo, such as sensors or satellites , into the higher layers of the atmosphere or into orbit . Advantages over conventional rocket technology would be significantly reduced costs due to a higher payload share and also a lower risk of accidents, among other things because no or less highly explosive rocket fuel would be carried.

Necessary muzzle velocities for payload-carrying projectiles are 9 km / s for a low earth orbit (for example for satellites) or 11.2 km / s, the escape velocity of the earth, for example for the probe launch.

history

Initiated and led by Canadian engineer Gerald Bull , the project was a joint effort between the United States Department of Defense and the Canadian Department of Defense . Beginning in 1961, the project was settled on the island of Barbados , near Seawell Airport (today Grantley Adams International Airport ), from where projectiles could safely be fired eastwards towards the Atlantic .

Gerald Bull designed a cannon for the HARP project based on decommissioned ship guns of the US Navy with an inner diameter of 40.6 cm (16  inches ), the largest available ship gun caliber. The cannon had a length of up to 36 m due to a later extension through a combination of two gun barrels. The actual projectile , called Martlet , was only 16.8 cm in diameter and was fired with a sabot or sabot that sealed the barrel . The Martlet projectiles later received an additional rocket drive .

The acceleration was facilitated by pumping the air out of the gun barrel. A light but airtight lid was attached in front of the gun muzzle, which was thrown away when the gun was fired. The electronic measuring instruments inside the rocket were encased in a mixture of epoxy resin and sand to protect them against the high acceleration forces.

In 1966, due to growing political squabbles, a second 16-inch HARP cannon was built, this time on American soil, in Yuma , Arizona. There, on November 18, 1966, the project group succeeded in firing a 180 kg Martlet 2 projectile at a muzzle velocity of 3600 m / s at an altitude of 180 km, i.e. on a suborbital trajectory . The world record in altitude achieved with it remains unbroken (as of 2013).

The HARP Project was founded in 1967 in the context of the Vietnam War ended and a chilled Canada-US relationship, shortly after the project and its equipment to Bull under the title Space Research Institute, Inc had been transferred. The project had received only $ 10 million in funding over its lifetime, because at the same time Wernher von Braun was doing high-budget research on ballistic missiles .

After the end of the project, the cannons and some other used and unused gun barrels remained at their place of installation on Barbados. These project remnants can still be viewed there (as of 2010), albeit in a badly disintegrated state, as no corrosion or weather protection was carried out.

For more information on related projects - see Gerald Bull .

SHARP

The American Lawrence Livermore National Laboratory ran the Super High Altitude Research Project (SHARP) in the early 1990s , which also tested a high-speed cannon. This space cannon project was intended to transport the payload into space at a twentieth of the previous cost, and relied on two-stage light gas cannon technology: In the first stage, a piston was driven by an explosion that compressed hydrogen. At 4000 bar pressure the valve to the actual cannon opened, which promised significantly higher projectile speeds of up to 7 km / s.

In December 1992 the L-shaped cannon was tested for the first time, the pump stage of which had a barrel of 82 m length and 36 cm caliber, the launch barrel 47 m length and 10 cm caliber. In the tests, speeds of 3 km / s were achieved with 5 kg projectiles. The next stage of development, which would have made kills into space and cost US $ 1 billion, was no longer approved in 1995. From 1996 the facility was used for tests with scramjet models. After the end of the financed research project, the company Quicklaunch was spun off by some project employees , which tries to further develop and commercialize the technology. Quicklaunch aimed to transport payloads into space for 1,100 US dollars per kg (compared to current costs of 12,000 euros per kg to 80,000 US dollars per kg). Since the target muzzle velocity of 6 to 7 km / s for the quick launch light gas cannon was not yet sufficient for a low earth orbit , the concept included an additional rocket stage.

literature

Web links

HARP

SHARP

Individual evidence

  1. ↑ a b Scott R. Gourley: The Jules Vernes Gun Archived from the original on October 29, 2011. (jpeg) In: quicklaunchinc.com (Ed.): Popular Mechanics . December 1996, pp. 54-57. Retrieved December 29, 2011.
  2. ↑ a b c Richard K Graf: A Brief History of the HARP Project in the Encyclopedia Astronautica, accessed on July 7, 2015 (English).
  3. ^ Charlene Crabb: Shooting at the moon . In: newscientist.com (Ed.): New Scientist . No. 1937, August 6, 1994. Retrieved December 29, 2011.
  4. ↑ quicklaunchinc.com/investors/space-exploration/ ( Memento from September 27, 2012 in the Internet Archive )
  5. ↑ Success story of space transport: Like Phoenix from the ashes.