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{{short description|Method of launching an object into outer space via a large gun or cannon}}
{{hatnote|Not to be confused with [[raygun]], a type of gun common in science fiction. For other uses, see [[Space gun (disambiguation)]].}}
[[File:Quicklauncher.jpg|thumb|The [[Quicklaunch]]er spacegun]]

A '''space gun''', sometimes called a '''Verne gun''' because of its appearance in ''[[From the Earth to the Moon]]'' by [[Jules Verne]], is a method of launching an object into [[outer space|space]] using a large [[gun]]- or [[cannon]]-like structure. Space guns could thus potentially provide a method of [[non-rocket spacelaunch]]. It has been conjectured that space guns could place [[satellites]] into Earth's orbit (although after-launch propulsion of the satellite would be necessary to achieve a stable orbit), and could also launch spacecraft beyond Earth's gravitational pull and into other parts of the [[Solar System]] by exceeding [[Escape velocity#List of escape velocities|Earth's escape velocity]] of about {{convert|40320|kph|km/s km/h mph|abbr=on|order=out}}. However, these speeds are too far into the [[Hypersonic speed|hypersonic]] range for most practical propulsion systems and also would cause most objects to burn up due to [[aerodynamic heating]] or be torn apart by [[aerodynamic drag]]. 
Therefore, a more likely future use of space guns would be to launch objects into [[Low Earth orbit]], at which point attached rockets could be fired or the objects could be "collected" by maneuverable orbiting satellites.{{citation needed|date=March 2018}}

In [[Project HARP]], a 1960s joint United States and Canada defence project, a [[United States Navy|U.S. Navy]] {{convert|16|in|mm|abbr=on|order=flip}} 100 [[Caliber#Caliber as measurement of length|caliber]] gun was used to fire a {{convert|180|kg|lb|abbr=on}} projectile at {{convert|12960|kph|m/s km/h mph|abbr=on|order=out}}, reaching an [[apogee]] of {{convert|180|km|mi|abbr=on}}, hence performing a [[suborbital spaceflight]]. However, a space gun has never been successfully used to launch an object into orbit or out of Earth's gravitational pull.

== Technical issues ==
The large [[g-force]] likely to be experienced by a [[Ballistics|ballistic]] projectile launched in this manner would mean that a space gun would be incapable of safely launching [[human]]s or delicate instruments, rather being restricted to [[freight]], fuel or ruggedized satellites.

===Getting to orbit===
A space gun by itself is not capable of placing objects into a stable orbit around the object (planet or otherwise) they are launched from.   The orbit is a [[parabolic orbit]], a [[hyperbolic orbit]], or part of an [[elliptic orbit]] which ends at the planet's surface at the point of launch or another point.  This means that an uncorrected ballistic payload will always strike the planet within its first orbit unless the velocity was so high as to reach or exceed [[escape velocity]]. As a result, all payloads intended to reach a closed orbit need at least to perform some sort of course correction to create another orbit that does not intersect the planet's surface.

A rocket can be used for additional boost, as planned in both [[Project HARP#Martlet projectiles|Project HARP]] and the [[Quicklaunch]] project.  The magnitude of such correction may be small; for instance, the [[StarTram|StarTram Generation 1]] reference design involves a total of {{cvt|0.6|km/s|mph}} of rocket burn to raise [[perigee]] well above the atmosphere when entering an {{cvt|8|km/s|mph}} [[low Earth orbit]].<ref>{{cite web|url=http://www.startram.com/resources|title=StarTram2010: Maglev Launch: Ultra Low Cost Ultra High Volume Access to Space for Cargo and Humans|publisher=startram.com|access-date=April 28, 2011}}</ref>

In a [[Three-body problem#Gravitational systems|three-body]]{{Broken anchor|date=2024-06-15|bot=User:Cewbot/log/20201008/configuration|target_link=Three-body problem#Gravitational systems|reason= The anchor (Gravitational systems) [[Special:Diff/881619468|has been deleted]].}} or larger system, a [[gravity assist]] trajectory might be available such that a carefully aimed [[escape velocity]] projectile would have its trajectory modified by the gravitational fields of other bodies in the system such that the projectile would eventually return to orbit the initial planet using only the launch [[delta-v]].<ref>{{citation |last=Clarke|first=Victor C. Jr.|title=An Essay On the Application and Principle of Gravity-Assist Trajectories For Space Flight|page=7|date=1970-04-10|url=http://gravityresearchfoundation.org/pdf/awarded/1970/clarke.pdf|access-date=2013-08-13|publisher=Jet Propulsion Laboratory, California Institute of Technology|quote=By induction then, it is obvious that the process of diverting a spacecraft from one planet to another might be continued indefinitely, if the planets were in favorable positions.|archive-url=https://web.archive.org/web/20160418190308/http://www.gravityresearchfoundation.org/pdf/awarded/1970/clarke.pdf|archive-date=2016-04-18}}</ref><ref>{{citation |last=Minovitch|first=Michael|title=A Method For Determining Interplanetary Free-Fall Reconnaissance Trajectories|series=Jet Propulsion Laboratory Technical Memos|number=TM-312-130|pages=38–44|date=August 23, 1961|url=http://www.gravityassist.com/Letters/LD-1.pdf#page=24}}</ref>

[[Isaac Newton]] avoided this objection in his thought experiment by placing his notional cannon atop a tall mountain and positing negligible air resistance. If in a stable orbit, the projectile would circle the planet and return to the altitude of launch after one orbit (see [[Newton's cannonball]]).<ref>{{cite book|last=Newton|first=Isaac|title=A Treatise of the System of the World|year=1728|publisher=F. Fayram|pages=6–12|url=https://play.google.com/books/reader?id=rEYUAAAAQAAJ&printsec=frontcover&output=reader&authuser=0&hl=en&pg=GBS.PA4}}</ref>

=== Acceleration ===
For a space gun with a [[gun barrel]] of length (<math>l</math>), and the needed velocity (<math>v_e</math>), the acceleration (<math>a</math>) is provided by the following formula:{{citation needed|date=May 2018}}

:<math> a = \frac{v_e^2}{2l} </math>

For instance, with a space gun with a vertical "gun barrel" through both the [[Earth's crust]] and the [[troposphere]], totalling ~{{convert|60|km|mi|abbr=in}} of length (<math>l</math>), and a velocity (<math>v_e</math>) enough to escape the Earth's gravity ([[escape velocity]], which is {{cvt|11.2|km/s|mph|disp=or}} on Earth), the acceleration (<math>a</math>) would theoretically be more than {{cvt|1000|m/s2}}, which is more than 100 [[g-force]]s, which is about 3 times the [[G-force#Human tolerance of g-force|human tolerance to g-force]]s of maximum 20 to 35 ''g''<ref name="Purley">{{cite web| title=David Purley Bio | url=http://www.asag.sk/bio/purley.htm | website=Anton Sukup's Autographs of F1 Drivers | access-date=July 31, 2006 |quote=Purley was subjected to the highest G-forces ever survived by a human being - 179.8G - when the car went from 108mph to zero in just over half a meter}}</ref> during the ~10 seconds such a firing would take.This calculation does not take into account the decreasing escape velocity at higher altitudes.

==Practical attempts==
[[File:Big Babylon sections at Fort Nelson.JPG|300px|thumb|Two sections of the [[Project Babylon]] gun]]
[[File:Project Harp.jpg|left|thumb|140px|[[Project HARP]], a prototype of a space gun.]]
===V3 Cannon (1944-45)===
The German [[V-3 cannon]] program, during World War II was an attempt to build something approaching a space gun. Based in the [[Pas-de-Calais]] area of [[France]] it was planned to be more devastating than the other [[Nazi]] '[[V-weapons|Vengeance weapons]]'. The cannon was capable of launching {{cvt|140|kg|lb}}, {{cvt|15|cm|in}} diameter shells over a distance of {{cvt|88|km|mi}}. It was destroyed by [[RAF]] bombing using [[Tallboy (bomb)|Tallboy]] [[blockbuster bomb]]s in July 1944.<ref>{{cite web|author=RAF staff |date=6 April 2005 |url=http://www.raf.mod.uk/bombercommand/diary.html |work=Bomber Command: Campaign Diary |title=RAF History - Bomber Command 60th Anniversary |publisher=RAF |archive-url=http://webarchive.nationalarchives.gov.uk/20070706011932/http://www.raf.mod.uk/bombercommand/jul44.html |archive-date=6 July 2007|access-date=23 October 2013}}</ref>

=== Super High Altitude Research Project (1985-95)===
The US [[Ballistic Missile Defense]] program sponsored the [[Super High Altitude Research Project]] (SHARP) in the 1980s. Developed at [[Lawrence Livermore Laboratory]], it is a [[light-gas gun]] and has been used to test fire objects at [[Mach number|Mach 9]].

===Project Babylon (1988-90)===
The most prominent recent attempt to make a space gun was artillery engineer [[Gerald Bull]]'s [[Project Babylon]], which was also known as the 'Iraqi supergun' by the media. During Project Babylon, Bull used his experience from Project HARP to build a massive cannon for [[Saddam Hussein]], leader of [[Ba'athist Iraq]]. Bull was assassinated before the project was completed.<ref>{{cite book|last=Lowther|first=William|title=Arms and the Man: Dr. Gerald Bull, Iraq, and the Supergun|year=1991|publisher=Presidio Press|isbn=978-0-89141-438-4}}</ref>

=== Quicklaunch (1996-2016)===
After cancellation of SHARP, lead developer [[John Hunter (scientist)|John Hunter]] founded the Jules Verne Launcher Company in 1996 and the [[Quicklaunch]] company.  As of September 2012, Quicklaunch was seeking to raise $500 million to build a gun that could refuel a [[propellant depot]] or send bulk materials into space.<ref>{{cite web | title=Quicklaunch Affordable Space Access| website=TekLaunch Inc. | url=http://quicklaunchinc.com/ | archive-url=https://web.archive.org/web/20110724205716/http://quicklaunchinc.com/ | archive-date=2011-07-24 | url-status=unfit}}</ref><ref>{{cite web | url=http://www.astronautix.com/lvs/julncher.htm | archive-url=https://web.archive.org/web/20020827222434/http://astronautix.com/lvs/julncher.htm  | archive-date=August 27, 2002 | title=Jules Verne Launcher Company Concept | publisher=astronautix.com | access-date=November 11, 2011}}</ref><ref>{{cite web | url=http://www.popsci.com/technology/article/2010-01/cannon-shooting-supplies-space | title=A Cannon for Shooting Supplies into Space |work=Popular Science |first=Amina |last=Elahi |date=January 15, 2010 |access-date=November 11, 2011}}</ref>

[[Ram accelerator]]s have also been proposed as an alternative to light-gas guns. Other proposals use electromagnetic techniques for accelerating the payload, such as [[coilgun]]s and [[railgun]]s.{{citation needed|date=May 2018}}

==In fiction==
[[File:FETMlaunch.jpg|right|thumb|150px|The firing of a space gun in Jules Verne's ''From the Earth to the Moon'']]
The first publication of the concept may be [[Newton's cannonball]] in his 1728 book ''[[A Treatise of the System of the World]]'', although it was primarily used as a [[thought experiment]] regarding gravity.<ref>{{cite book |chapter-url=http://www.vectorsite.net/tarokt_4.html |chapter=[4.0] Space Guns |title=Spaceflight Propulsion |edition=v1.4.0 |date=1 November 2019 |author=Greg Goebel}}</ref>

Perhaps the most famous representations of a space gun appear in [[Jules Verne]]'s 1865 novel ''[[From the Earth to the Moon]]'' and his 1869 novel ''[[Around the Moon]]'' (loosely interpreted into the 1902 film ''[[Le Voyage dans la Lune]]''), in which astronauts fly to the Moon aboard a ship launched from a cannon. Another famous example is used by the [[Martian (The War of the Worlds)|Martians]] to launch their invasion in [[H. G. Wells]]' 1897 book ''[[The War of the Worlds]]''. Wells also used the concept in the climax of the 1936 film ''[[Things to Come]]''. In one of the first Polish Sci-Fi novels, ''[[The Lunar Trilogy|On the Silver Globe]]'' by [[Andrzej Żuławski]], published in 1903, astronauts are launched to the Moon using a space gun. The device was featured in films as late as 1967, such as ''[[Jules Verne's Rocket to the Moon]]''.

In the 1991 video game ''[[Ultima: Worlds of Adventure 2: Martian Dreams]]'', [[Percival Lowell]] builds a space gun to send a spacecraft to [[Mars]].

The 1992 video game ''[[Steel Empire]]'', a [[shoot 'em up]] with [[steampunk]] aesthetics, features a space gun in its seventh level that is used by the main villain General Styron to launch himself to the Moon.

In [[Hannu Rajaniemi]]'s 2012 novel ''[[The Fractal Prince]]'', a space gun at the "Jannah-of-the-cannon", powered by a 150-kiloton [[nuclear bomb]], is used to launch a spaceship from Earth.

The 2015 video game ''[[Soma (video game)|SOMA]]'' features a space gun used to launch satellites.

[[Gerald Bull]]'s assassination and the [[Project Babylon]] gun were also the starting point for [[Frederick Forsyth]]'s 1994 novel ''[[The Fist of God]]''. In [[Larry Bond]]'s 2001 novella and 2015 novel ''Lash-Up'', China uses a space gun to destroy American [[GPS]] satellites.

In the 2004 role-playing game ''[[Paper Mario: The Thousand-Year Door]]'', a village of Bob-ombs operates a space gun to send Paper Mario and company to the X-Naut's base on the Moon.

Gerald Bull and Project Babylon are integral to the plot of [[Louise Penny]]'s 2015 novel ''The Nature of the Beast''.

==See also==
{{Portal| Spaceflight }}
* [[Geostationary orbit]]: circular orbit {{convert|35786|km|mi|abbr=in}} above the Earth used by communications satellites
* [[Newton's cannonball]]
* ''[[The Fist of God]]''
* [[Super High Altitude Research Project|SHARP]]
* [[Quicklaunch]]
* [[SpinLaunch]]
* [[StarTram]]
* [[Mass driver]]
* [[Space elevator]]
* [[Launch loop]]
* [[Lightcraft]]
* [[Space fountain]]
* [[Tether propulsion]]
* [[Non-rocket spacelaunch]]

==References==
{{Reflist}}

==External links==
* [https://www.army.mil/article/205046/new_technology_testing_may_achieve_the_goals_of_harp_space_gun New technology testing may achieve the goals of HARP "space" gun]
* [http://www.fas.org/news/iraq/1998/05/980500-bull.htm FAS space gun page]
* [http://nextbigfuture.com/2010/03/150-kiloton-nuclear-verne-gun.html The 150 Kiloton Nuclear Verne Gun]
* [https://greenlaunch.org/ Green Launch]

{{Non-rocket spacelaunch}}

{{DEFAULTSORT:Space Gun}}
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