Editing Apollo 10 (section)

{{short description|Second crewed mission to orbit the Moon}}
{{pp-move|small=yes}}
{{Use mdy dates|date=March 2012}}
{{Use American English|date=January 2014}}
{{Featured article}}
{{Infobox spaceflight
| name                  = Apollo 10
| image                 = Apollo 10 Lunar Module.jpg
| image_caption         = Apollo 10's [[Apollo Lunar Module|Lunar Module]], ''Snoopy'', approaches the [[Apollo command and service module|Command and Service Module]] ''Charlie Brown'' for redocking

| mission_type          = Crewed lunar orbital CSM/LM flight ([[List of Apollo missions#Alphabetical mission types|F]])
| operator              = [[NASA]]
| COSPAR_ID             = {{Unbulleted list
  |'''CSM''': {{COSPAR|1969-043A}}<ref name="summary">{{Cite web |title=Apollo 10 summary |url=https://history.nasa.gov/SP-4029/Apollo_10a_Summary.htm |access-date=July 16, 2022 |publisher=[[NASA]]}}</ref>
  |'''LM''': {{COSPAR|1969-043C}}
}}
| SATCAT                = {{Unbulleted list
  |'''CSM''': 3941
  |'''LM''': 3948
}}
| mission_duration      = 8&nbsp;days, 3&nbsp;minutes, 23&nbsp;seconds

| spacecraft            = {{Unbulleted list
  |[[Apollo command and service module|Apollo CSM]]-106
  |[[Apollo Lunar Module|LM]]-4
}}
| manufacturer          = {{Unbulleted list
  |'''CSM''': [[North American Rockwell]]
  |'''LM''': [[Grumman]]
}}
| launch_mass           = {{cvt|42775|kg}}<ref>{{Cite web |title=Apollo 10 |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1969-043A |access-date=November 29, 2022 |publisher=[[NASA Space Science Data Coordinated Archive]] (NSSDCA)}}</ref>
| landing_mass          = {{cvt|10901|lb|kg|order=flip}}

| crew_size             = 3
| crew_members          = {{Unbulleted list
  |[[Thomas P. Stafford]]
  |[[John Young (astronaut)|John W. Young]]
  |[[Gene Cernan|Eugene A. Cernan]]
}}
| crew_callsign         = {{Unbulleted list
  |'''CSM''': ''Charlie Brown''
  |'''LM''': ''Snoopy''
}}

| launch_date           = {{start date text|May 18, 1969, 16:49:00|timezone=yes}}&nbsp;UTC<ref>{{Citation |title=Apollo 10 |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1969-043A |access-date=November 29, 2022 |publisher=[[NASA Space Science Data Coordinated Archive]] (NSSDCA)}}</ref>
| launch_rocket         = [[Saturn V]] SA-505
| launch_site           = [[Kennedy Space Center|Kennedy]], [[Kennedy Space Center Launch Complex 39B|LC-39B]]

| recovery_by           = {{USS|Princeton|CV-37|6}}
| landing_date          = {{end date text|May 26, 1969, 16:52:23|timezone=yes}}&nbsp;UTC
| landing_site          = [[Pacific Ocean]] near [[American Samoa]] ({{Coord|15|2|S|164|39|W|type:event|name=Apollo 10 splashdown}})

| orbit_reference       = [[Selenocentric orbit]]
| orbit_periapsis       = {{convert|59.2|nmi|km|abbr=on|disp=out}} (59.2&nbsp;[[Nautical mile|nmi]]; {{convert|59.2|nmi|mi|abbr=on|disp=out}})
| orbit_apoapsis        = {{convert|61|nmi|km|abbr=on|disp=out}} (61&nbsp;nmi; {{convert|61.0|nmi|mi|abbr=on|disp=out}})
| apsis                 = selene
| orbit_inclination     = 1.2°
| orbit_period          = 2&nbsp;hours

|interplanetary         = {{Infobox spaceflight/IP
   |type                = orbiter
   |object              = [[Moon|Lunar]]
   |component           = [[Apollo command and service module|Command and service module]]
   |orbits              = 31
   |arrival_date        = May 21, 1969, 20:44:54&nbsp;UTC
   |departure_date      = May 24, 1969, 10:25:38&nbsp;UTC
   }}
   {{Infobox spaceflight/IP
   |type                = orbiter
   |object              = [[Moon|Lunar]]
   |component           = [[Apollo Lunar Module|Lunar Module]]
   |orbits              = 4 (while solo)
   |periapsis           = {{convert|7.8|nmi|km|abbr=on|disp=out}} (7.8&nbsp;nmi; {{convert|7.8|nmi|mi|abbr=on|disp=out|0}})
   |apsis               = selene
   |arrival_date        = May 22, 1969, 20:35:01&nbsp;UTC<!-- LM descent orbit insertion ignition -->
   |departure_date      = May 22, 1969, 23:44:02&nbsp;UTC<!-- LM ascent orbit insertion ignition -->
   }}

| docking               = {{Infobox spaceflight/Dock
   | docking_target     = LM
   | docking_type       = dock
   | docking_date       = May 18, 1969, 20:06:36&nbsp;UTC
   | undocking_date     = May 22, 1969, 19:00:57&nbsp;UTC
   | time_docked        = {{time interval|May 18, 1969, 20:06:36|May 22, 1969, 19:00:57|show=dhm|sep=,}}
   }}
   {{Infobox spaceflight/Dock
   | docking_target     = LM Ascent Stage
   | docking_type       = dock
   | docking_date       = May 23, 1969, 03:11:02&nbsp;UTC
   | undocking_date     = May 23, 1969, 05:32:23&nbsp;UTC
   | time_docked        = {{time interval|May 23, 1969, 03:11:02|May 23, 1969, 05:32:23|show=dhm|sep=,}}
   }}

| insignia              = Apollo-10-LOGO.png
| insignia_caption      = Mission patch

| crew_photo            = The Apollo 10 Prime Crew - GPN-2000-001163.jpg
| crew_photo_caption    = Left to right: [[Gene Cernan|Cernan]], [[Thomas P. Stafford|Stafford]], [[John Young (astronaut)|Young]]

| programme             = [[Apollo program]]
| previous_mission      = [[Apollo 9]]
| next_mission          = [[Apollo 11]]
}}

'''Apollo 10''' (May 18–26, 1969) was the fourth [[human spaceflight]] in the United States' [[Apollo program]] and the second to orbit the [[Moon]]. [[NASA]], the mission's operator, described it as a "dress rehearsal" for the first [[Moon landing]] ([[Apollo 11]], two months later{{sfn|Press Kit|p=1}}).<!-- The source is only for NASA's description of Apollo 10 as a dress rehearsal --> It was designated an [[List of Apollo missions#Alphabetical mission types|"F"{{nbsp}}mission]], intended to test all [[spacecraft]] components and procedures short of actual descent and landing.

After the spacecraft reached lunar orbit, astronaut [[John Young (astronaut)|John Young]] remained in the [[Apollo Command and Service Module|Command and Service Module]] (CSM) while astronauts [[Thomas P. Stafford|Thomas Stafford]] and [[Gene Cernan]] flew the [[Apollo Lunar Module]] (LM) to within {{convert|7.8|nmi|km|abbr=off|disp=out|lk=on|sp=us|1}} (7.8&nbsp;[[nautical miles]]; {{convert|7.8|nmi|mi|abbr=off|disp=out|lk=on|0}}) of the [[lunar surface]], the point at which powered descent for landing would begin on a landing mission. After four orbits they rejoined Young in the CSM and, after the CSM completed its 31st orbit of the Moon, they returned safely to Earth.

While NASA had considered attempting the first crewed lunar landing on Apollo 10, mission planners ultimately decided that it would be prudent to have a practice flight to hone the procedures and techniques. The crew encountered some problems during the flight: [[pogo oscillations]] during the launch phase and a brief, uncontrolled tumble of the LM ascent stage in lunar orbit during its solo flight. However, the mission accomplished its major objectives. Stafford and Cernan observed and photographed Apollo 11's planned landing site in the [[Sea of Tranquility]]. Apollo 10 spent 61 hours and 37 minutes orbiting the Moon, for about eight hours of which Stafford and Cernan flew the LM apart from Young in the CSM, and about eight days total in space. Additionally, Apollo 10 set the record for the highest speed attained by a crewed vehicle: 39,897&nbsp;kilometers per hour (11.08&nbsp;kilometers per second or 24,791&nbsp;miles per hour) on May 26, 1969, during the return from the Moon.

The mission's [[call sign]]s were the names of the ''[[Peanuts]]'' characters [[Charlie Brown]] for the CSM and [[Snoopy]] for the LM, who became Apollo 10's semi-official mascots.<ref>{{Cite web |date=May 28, 1969 |title=Replicas of Snoopy and Charlie Brown decorate top of console in MCC |url=http://science.ksc.nasa.gov/mirrors/images/images/pao/AS10/10075138.jpg |url-status=dead |archive-url=https://web.archive.org/web/20010619231200/http://science.ksc.nasa.gov/mirrors/images/images/pao/AS10/10075138.jpg |archive-date=June 19, 2001 |access-date=June 25, 2013 |publisher=[[NASA]] |id=NASA Photo ID: S69-34314}} Photo description available [http://science.ksc.nasa.gov/mirrors/images/images/pao/AS10/10075138.htm here] {{Webarchive|url=https://web.archive.org/web/20211005150651/https://science.ksc.nasa.gov/mirrors/images/images/pao/AS10/10075138.htm|date=October 5, 2021}}.</ref> ''Peanuts'' creator [[Charles Schulz]] also drew mission-related artwork for NASA.<ref>{{Cite web |last=McKinnon |first=Mika |date=April 30, 2014 |title=Snoopy the Astrobeagle, NASA's Mascot for Safety |url=https://gizmodo.com/snoopy-the-astrobeagle-nasas-mascot-for-safety-1570066950 |access-date=6 June 2019 |website=[[Gizmodo]]}}</ref>