Space gun: Difference between revisions

{{hatnote|Not to be confused with [[Raygunraygun]], a type of gun common in science fiction. For other uses, see [[Space gun (disambiguation)]].}}

A space gun by itself is not capable of placing objects into a stable orbit around the object (planet or otherwise) fromthey whichare itlaunched launches themfrom. 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]].{{citation needed|date=May 2018}}. 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|accessdateaccess-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>{{citecitation journal|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|accessdateaccess-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-status=dead|archiveurl=https://web.archive.org/web/20160418190308/http://www.gravityresearchfoundation.org/pdf/awarded/1970/clarke.pdf|archivedatearchive-date=2016-04-18}}</ref><ref>{{citecitation journal|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 positingplacing anhis impossiblynotional cannon atop a tall mountain fromand whichpositing his cannonnegligible wasair firedresistance. 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>

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| author=Anton Sukup| title=''David PURLEY''Purley SilverstoneBio crash| year=1977| url=http://www.asag.sk/bio/purley.htm | website=Anton Sukup's Autographs of F1 Drivers | accessdateaccess-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.

=== Quicklaunch (1996-2016)===

After cancellation of SHARP, lead developersdeveloper [[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/ | titlearchive-url=https://web.archive.org/web/20110724205716/http://quicklaunchinc.com/ | accessdatearchive-date=November2011-07-24 11,| 2011url-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 | accessdateaccess-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 publisherScience |first=popsci.comAmina |last=Elahi accessdate|date=January 15, 2010 |access-date=November 11, 2011}}</ref>

The first publication of the concept may be [[Newton's cannonball]] in thehis 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 vectorsite.net > |chapter=[4.0] Space Guns] |title=Spaceflight Propulsion |edition=v1.14.40 /|date=1 chapterNovember 4 of 7 / 01 jun 08 / greg goebel /2019 public|author=Greg domainGoebel}}</ref>

Perhaps the most famous representationrepresentations of a space gun isappear in [[Jules Verne]]'s novels1865 novel ''[[From the Earth to the Moon]]'' and his 1869 novel ''[[Around the Moon]]'' (loosely interpreted into the early1902 film ''[[Le Voyage dans la Lune]]''), in which astronauts fly to the moonMoon aboard a ship launched from a cannon. Another famous example is the hydrogen accelerator cannon 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 moviefilm ''[[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 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 moonMoon.

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

* ''[[The Fist of God]]''

[[Category:Spaceflight technologiestechnology]]