Editing Pioneer 10 (section)

===History===
In the 1960s, American aerospace engineer [[Gary Flandro]] of the NASA [[Jet Propulsion Laboratory]] conceived of a mission, known as the [[Planetary Grand Tour]], that would exploit a rare alignment of the outer planets of the Solar System. This mission would ultimately be accomplished in the late 1970s by the two [[Voyager program|Voyager]] probes, but in order to prepare for it, NASA decided in 1964 to experiment with launching a pair of probes to the [[outer Solar System]].{{sfn|Launius|2004|p=36}} An advocacy group named the Outer Space Panel and chaired by American space scientist [[James A. Van Allen]], worked out the scientific rationale for exploring the outer planets.{{sfn|Van Allen|2001|p=155}}{{sfn|Burrows|1990|pp=16}} NASA [[Goddard Space Flight Center|Goddard]] Spaceflight Center put together a proposal for a pair of "Galactic Jupiter Probes" that would pass through the asteroid belt and visit Jupiter. These were to be launched in 1972 and 1973 during favorable windows that occurred only a few weeks every 13 months. Launch during other time intervals would have been more costly in terms of propellant requirements.{{sfn|Burrows|1999|p=476}}

Approved by NASA in February 1969,{{sfn|Burrows|1999|p=476}} the twin spacecraft were designated ''Pioneer&nbsp;F'' and ''Pioneer&nbsp;G'' before launch; later, they were named ''Pioneer 10'' and ''[[Pioneer 11]]'' respectively. They formed part of the [[Pioneer program]],{{sfn|Burgess|1982|p=16}} a series of United States uncrewed space missions launched between 1958 and 1978. This model was the first in the series to be designed for exploring the outer Solar System. Based on proposals issued throughout the 1960s, the early mission objectives were to explore the interplanetary medium past the orbit of Mars, study the asteroid belt and assess the possible hazard to spacecraft traveling through the belt, and explore Jupiter and its environment.<ref name=NASA_sp349_396/> Later development-stage objectives included the probe closely approaching Jupiter to provide data on the effect the environmental radiation surrounding Jupiter would have on the spacecraft instruments.

More than 150 scientific experiments were proposed for the missions.{{sfn|Simpson|2001|p=144}} The experiments to be carried on the spacecraft were selected in a series of planning sessions during the 1960s, then were finalized by early 1970. These would be to perform imaging and [[polarimetry]] of Jupiter and several of its satellites, make infrared and ultraviolet observations of Jupiter, detect asteroids and meteoroids, determine the composition of charged particles, and to measure magnetic fields, plasma, cosmic rays and the [[zodiacal light]].<ref name=NASA_sp349_396/> Observation of the spacecraft communications as it passed behind Jupiter would allow measurements of the planetary atmosphere, while tracking data would improve estimates of the mass of Jupiter and its moons.<ref name=NASA_sp349_396/>

[[NASA Ames Research Center]], rather than Goddard, was selected to manage the project as part of the Pioneer program.{{sfn|Burrows|1999|p=476}} The Ames Research Center, under the direction of Charles F. Hall, was chosen because of its previous experience with spin-stabilized spacecraft. The requirements called for a small, lightweight spacecraft which was magnetically clean and which could perform an interplanetary mission. It was to use spacecraft modules that had already been proven in the ''Pioneer&nbsp;6'' through ''9'' missions.<ref name=NASA_sp349_396/> Ames commissioned a documentary film by George Van Valkenburg titled ''Jupiter Odyssey''. It received numerous international awards, and is visible on Van Valkenburg's YouTube channel.

In February 1970, Ames awarded a combined US$380&nbsp;million contract to [[TRW Inc.]] for building both of the ''Pioneer&nbsp;10'' and ''11'' vehicles, bypassing the usual bidding process to save time. B. J. O'Brien and Herb Lassen led the TRW team that assembled the spacecraft.{{sfn|Dyer|1998|p=302}} Design and construction of the spacecraft required an estimated 25&nbsp;million man-hours.{{sfn|Wolverton|2004|p=124}}  An engineer from TRW quipped, "This spacecraft is guaranteed for two years of interplanetary flight. If any component fails within that warranty period, just return the spacecraft to our shop and we will repair it free of charge."<ref>{{cite magazine |url= http://aviationweek.com/awin/pioneer-beat-warranty|title= PIONEER BEAT 'WARRANTY'|magazine= Aviation Week |access-date= September 15, 2017}}</ref>

To meet the schedule, the first launch would need to take place between February 29 and March 17 so that it could arrive at Jupiter in November 1974. This was later revised to an arrival date of December 1973 in order to avoid conflicts with other missions over the use of the [[Deep Space Network]] for communications, and to miss the period when Earth and Jupiter would be at opposite sides of the Sun. The encounter trajectory for ''Pioneer&nbsp;10'' was selected to maximize the information returned about the radiation environment around Jupiter, even if this caused damage to some systems. It would come within about three times the radius of the planet, which was thought to be the closest it could approach and still survive the radiation. The trajectory chosen would give the spacecraft a good view of the sunlit side.{{sfn|Burrows|1990|pp=16&ndash;19}}

<gallery mode="packed" heights="180">
File:Pioneer 10 systems diagram.svg|''Pioneer 10'' and ''Pioneer 11'' spacecraft diagram
File:Pioneer 10 Construction.jpg|''Pioneer 10'' in the final stages of construction (December 1971)
File:Testing Pioneer F Spacecraft - GPN-2000-001626.jpg|''Pioneer 10'' tested in a space simulation chamber  (January 1972)
File:Pioneer 10 on its kickmotor.jpg|''Pioneer 10'' on a [[Star-37E]] kick motor just prior to being encapsulated for launch (February 1972)
File:Centaur pio10.jpg|Pioneer 10 during encapsulation into payload fairing
</gallery>