Project HARP: Difference between revisions

'''Project HARP''', short for '''Highhigh Altitudealtitude Researchresearch Projectproject''', was a joint venture of the [[United States Department of Defense]] and [[Canada]]'s [[Department of National Defence (Canada)|Department of National Defence]] created with the goal of studying [[ballistics]] of [[re-entry vehicle]]s and collecting upper atmospheric data for research. Unlike conventional space launching methods that rely on rockets, HARP instead used very large guns to fire projectiles into the atmosphere at extremely high speeds.<ref name=":1">{{Cite journal |last1=Petrescu |first1=Relly |last2=Aversa |first2=Raffaella |last3=Akash |first3=Bilal |last4=Berto |first4=Filippo |last5=Apicella |first5=Antonio |last6=Petrescu |first6=Florian |date=2017 |title=Project HARP |journal=Journal of Aircraft and Spacecraft Technology |volume=1 |issue=4 |pages=249–257 |ssrn=3092679 |doi=10.3844/jastsp.2017.249.257 |doi-access=free }}{{predatory publisher}}</ref><ref name=":2">{{Cite magazine |last=Hanson |first=Joe |url=https://www.wired.com/2013/07/science-goes-ballistic-8-guns-for-hunting-knowledge/ |title=Science Goes Ballistic: 8 Guns for Hunting Knowledge |date=July 8, 2013 |magazine=Wired |access-date=February 11, 2020 }}</ref>

A {{convert|16|in|cm|adj=on}} HARP gun operated by the U.S. Army's [[Ballistic Research Laboratory]] (now called the [[United States Army Research Laboratory|U.S. Army Research Laboratory]]) at [[Yuma Proving Ground]] currently holds the world record for the highest altitude, {{convert|180|km|mi|abbr=on}}, that a gun-fired projectile has achieved: {{convert|180|km|mi|1}}.<ref name=":3">{{Cite web |url=http://www.astronautix.com/a/abriefhistoheharpproject.html |archive-url=https://web.archive.org/web/20160820020119/http://www.astronautix.com/a/abriefhistoheharpproject.html |url-status=dead |archive-date=August 20, 2016 |title=A Brief History of the HARP Project |last=Graf |first=Richard |website=Encyclopedia Astronautica |access-date=February 11, 2020}}</ref><ref name=":5">{{Cite news |last=Sterling |first=Bruce |url=https://www-istp.gsfc.nasa.gov/stargaze/SGbull.htm |title=Think of the Prestige |date=September 1992 |work=The Magazine of Fantasy and Science Fiction |access-date=February 11, 2020 }}</ref>

Project HARP originated as the brainchild of [[Gerald Bull]], a renowned but controversial ballistic engineer specializing in high-velocity guns and gun propulsion systems.<ref name=":2" /><ref name=":3" /> In the mid-1950s, Bull was working on [[Anti-ballistic missile|Antianti-Ballisticballistic Missilemissile (ABM)]] and [[Intercontinental ballistic missile|Intercontinentalintercontinental Ballisticballistic Missilemissile (ICBM)]] research at the [[DRDC Valcartier|Canadian Armaments and Research Development Establishment (CARDE)]] when he formulated the idea to launch [[satellite]]s into orbit using an enormous cannon.<ref name=":1" /><ref name=":3" /> Bull believed that a large supergun would be significantly more cost-effective at sending objects into space than a conventional rocket. Bull argued it would not need expensive rocket motors, firing a large gun wouldn't require the missile to throw away multiple [[Multistage rocket|rocket stages]] to break through the Earth's atmosphere to reach orbit.<ref>{{Cite news|last=Park|first=William|url=https://www.bbc.com/future/article/20160317-the-man-who-tried-to-make-a-supergun-for-saddam-hussein|title=The tragic tale of Saddam Hussein's 'supergun'|date=March 17, 2016|work=BBC|access-date=February 11, 2020}}</ref> In theory, a [[Sabot (firearms)|sabot]] would protect the payload during firing and later fall away as the satellite inside emerges.<ref name=":6">{{Cite news|last=Grundhauser|first=Eric|url=https://www.atlasobscura.com/places/project-harp-space-gun-barbados|title=Project HARP Space Gun|date=May 2017|work=Atlas Obscura|access-date=February 11, 2020}}</ref>

The 5-inch HARP guns were based on a modified [[120 mm Gungun M1|120&nbsp;mm T123 service gun]] and used by the [[Ballistic Research Laboratory]] before the HARP program in order to fulfill the needs of the U.S. military's Meteorological Rocket Network, a program dedicated to collecting atmospheric wind and temperature data. They were designed to carry a 0.9&nbsp;kg payload to an altitude of 65&nbsp;km, which consisted of radar reflective chaff to collect wind data and small [[radiosonde]]s that returned radio telemetry of information like temperature and humidity as they drifted back down under large parachutes.<ref name=":4" /><ref name=":15">{{Cite journal|last=Kampe|first=H.J.|date=October 1960|title=Meteorological Rocket Network: For Measuring Atmospheric Parameters up to 250.000|journal=Weatherwise|volume=13|issue=5|pages=192–195|doi=10.1080/00431672.1960.9940979|bibcode=1960Weawi..13e.192K }}</ref> This initial design for the 5-inch HARP gun reached an altitude of 130,000&nbsp;ft when tested in 1961.<ref name=":14" /> The 5-inch L70 smoothbore guns was the first vertical firing gun system developed under Project HARP.<ref name=":11" /> In 1962, a 10-ft extension was implemented for the 5-inch HARP gun by welding a second barrel section to the first, allowing it to launch projectiles at muzzle velocities of 1554&nbsp;m/s (5,100&nbsp;ft/sec) to altitudes of 73,100&nbsp;m (240,000&nbsp;ft).<ref name=":14" /> Throughout HARP, further modifications were made to the 5-inch gun, such as adding three sets of stiffening wires to maintain barrel alignment. Due to their small size, they were easily transported from their initial site at Aberdeen Proving Ground to different launch sites across North America and the Caribbean.<ref name=":4" /><ref name=":15" /> One of the 5-inch HARP guns was acquired by the Atmospheric Sciences Laboratory (which consolidated into the U.S. Army Research Laboratory in 1992) to measure the stratosphere's winds.<ref>{{Cite news|last=Kennedy|first=Bruce|url=http://www.wsmr-history.org/HandsAcrossHistory-02-15.pdf|title=Gun Probe Was Used To Study Winds|date=February 2015|work=Hands Across History|access-date=February 11, 2020}}</ref> The 5-inch gun was deemed successful as a low-cost launch system, costing only around $300 to $500 per launch.<ref name=":4" /> By May 1966, a total of the HARP program's 5-inch guns launched 162 flights at Wallops Island, 47 flights at White Sands Missile Range, 30 flights at Barbados, and 24 flights at Fort Greeley.<ref name=":14" />