View source for Engineering:Space probe

[[File:Pioneer H.JPG|250px|thumb|Abandoned 1974 [[Astronomy:Pioneer H|Pioneer H]] spaceprobe, on display in the National Air and Space Museum]]{{Needs more references|date=March 2022}}{{short description|Unmanned spacecraft that doesn't orbit the Earth, but, instead, explores further into outer space}}
A '''space probe''' is an [[Astronomy:Satellite|artificial satellite]] that travels through space to collect [[Data|scientific data]].<ref>{{Cite web |date=25 February 2010 |title=NASA – What Is a Space Probe? |url=https://www.nasa.gov/centers/jpl/education/spaceprobe-20100225.html |access-date=4 June 2022 |website=[[Organization:NASA|NASA]] |language=en}}</ref> A space probe may orbit [[Astronomy:Earth|Earth]]; approach the [[Astronomy:Moon|Moon]]; travel through interplanetary space; [[Engineering:Planetary flyby|flyby]], [[Physics:Orbit|orbit]], or [[Engineering:Landing|land]] or fly on other [[Astronomy:Planetary system|planetary]] [[Astronomy:Astronomical object|bodies]]; or enter interstellar space.

Many countries and private companies have launched probes to planets, asteroids, moons around the [[Astronomy:Solar System|Solar System]], including the [[Place:Soviet Union|Soviet Union]], the {{wipe|United States}}, {{wipe|India}}, and many more.

== History ==
{{further|Astronomy:List of Solar System probes}}

On 4 October 1957, the first artificial satelite to orbit Earth was [[Engineering:Sputnik 1|Sputnik 1]], launched by the USSR. One year later, on 1 February 1958, [[Astronomy:Explorer 1|Explorer 1]] was launched by the United States, being the first space probe. Explorer 1, collecting data on temperature, cosmic rays, and micrometeorite impacts.<ref>{{cite web |title=NASA Jet Propulsion Laboratory – Explorer 1 |url=https://explorer1.jpl.nasa.gov/about/#the_success}}</ref> The first attempted lunar probe was the [[Engineering:Luna E-1 No.1|Luna E-1 No.1]], launched on 23 September 1958. The goal of a lunar probe repeatedly failed until 4 January 1959 when [[Engineering:Luna 1|Luna 1]] orbited around the moon and then the sun. 

The success of these early missions began a race between the US and the USSR to outdo each other with increasingly ambitious probes. Each new satellite cast a shadow on the one that came before. ''[[Astronomy:Mariner 2|Mariner 2]]'' was the first probe to study another planet, revealing Venus' extremely hot temperature to scientists in 1962, while the Soviet ''[[Astronomy:Venera 4|Venera 4]]'' was the first atmospheric probe to study Venus. ''[[Astronomy:Mariner 4|Mariner 4]]'' 's 1965 Mars flyby snapped the first images of its cratered surface, which the Soviets responded to a few months later with images from on its surface from ''[[Astronomy:Luna 9|Luna 9]]''. In 1967, America's ''[[Astronomy:Surveyor 3|Surveyor 3]]'' gathered information about the Moon's surface that would prove crucial to the ''[[Engineering:Apollo 9|Apollo 11]]'' mission that landed humans on the moon two years later.<ref>{{cite web |title=NASA Jet Propulsion Laboratory|url=https://www.nasa.gov/centers/jpl/education/spaceprobe-20100225.html}}</ref>

The first interstellar probe was [[Astronomy:Voyager 1|Voyager 1]], launched 5 September 1977. It entered interstellar space on 25 August 2012,<ref>{{Cite news |last=Barnes |first=Brooks |date=12 September 2013 |title=In a Breathtaking First, NASA's Voyager 1 Exits the Solar System |language=en-US |work=The New York Times |url=https://www.nytimes.com/2013/09/13/science/in-a-breathtaking-first-nasa-craft-exits-the-solar-system.html |access-date=1 August 2022 |issn=0362-4331}}</ref> followed by its twin [[Astronomy:Voyager 2|Voyager 2]] on 5 November 2018. <ref>{{Cite web |last=Potter |first=Sean |date=9 December 2018 |title=NASA's Voyager 2 Probe Enters Interstellar Space |url=http://www.nasa.gov/press-release/nasa-s-voyager-2-probe-enters-interstellar-space |access-date=1 August 2022 |website=NASA}}</ref> Both have collected science outside the heliosphere.
== Characteristics ==
A space probe generally need an antenna to communicate back with Earth.

== Trajectories ==
Once a probe has left the vicinity of Earth, its trajectory will likely take it along an [[Astronomy:Heliocentric orbit|orbit around the]] [[Astronomy:Sun|Sun]] similar to the Earth's orbit. To reach another planet, the simplest practical method is a [[Astronomy:Hohmann transfer orbit|Hohmann transfer orbit]]. More complex techniques, such as gravitational slingshots, can be more fuel-efficient, though they may require the probe to spend more time in transit. Some high Delta-V missions (such as those with high [[Astronomy:Orbital inclination change|inclination changes]]) can only be performed, within the limits of modern propulsion, using gravitational slingshots. A technique using very little propulsion, but requiring a considerable amount of time, is to follow a trajectory on the [[Interplanetary Transport Network]].<ref>{{cite web |title=E&S+ |url=http://pr.caltech.edu/periodicals/EandS/articles/LXV4/exit.html}}</ref>

== See also ==
{{Portal|Spaceflight|Space
}}

* [[Astronomy:List of Solar System probes|List of Solar System probes]]
* [[Astronomy:Satellite|Satellite]]
* [[Astronomy:Space exploration|Space exploration]]

== References ==
{{Reflist}}

{{Solar System probes}}
{{Mobile robots}}
{{Robotics}}
{{Spaceflight}}

{{DEFAULTSORT:Space Probe}}
[[Category:Uncrewed spacecraft]]

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