Editing Gemini 4

{{Short description|Second crewed space flight in NASA's Project Gemini}}
{{Use American English|date=January 2014}}
{{Infobox spaceflight
| name               = Gemini IV
| image              = Ed White First American Spacewalker - GPN-2000-001180.jpg
| image_caption      = [[Ed White (astronaut)|Ed White]], the first American to perform [[extravehicular activity]], outside of Gemini IV
| mission_type       = [[Extravehicular activity]]
| operator           = [[NASA]]
| COSPAR_ID          = 1965-043A<ref>{{cite web|title=NSSDC Master Catalog: Gemini 4|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1965-043A|publisher=NASA|access-date=September 4, 2013}}</ref>
| SATCAT             = 1390<ref name=satcat>{{cite web|title=Satellite Catalog|url=http://planet4589.org/space/log/satcat.txt|access-date=September 4, 2013}}</ref>
| mission_duration   = 4&nbsp;days, 1&nbsp;hour, 56&nbsp;minutes, 12&nbsp;seconds
| distance_travelled = {{convert|2590600|km|mi nmi|sp=us|abbr=off}}
| orbits_completed   = 66 (62 revolutions)
| spacecraft         = [[Gemini (spacecraft)|Gemini]] SC4
| manufacturer       = [[McDonnell Aircraft|McDonnell]]
| launch_mass        = {{convert|7880|lb|kg|order=flip}}
| landing_mass       = 
| launch_date        = {{start-date|June 3, 1965, 15:15:59|timezone=yes}}&nbsp;UTC
| launch_rocket      = {{nowrap|[[Titan II GLV]],}} {{nowrap|s/n 62-12559}}
| launch_site        = [[Cape Canaveral Air Force Station|Cape Kennedy]] [[Cape Canaveral Air Force Station Launch Complex 19|LC-19]]
| landing_date       = {{end-date|June 7, 1965, 17:12:11|timezone=yes}}&nbsp;UTC
| landing_site       = North Atlantic Ocean<br/>{{coord|27|44|N|74|11|W}}
| recovery_by        = {{USS|Wasp|CV-18|6}}
| orbit_epoch        = June 3, 1965<ref name=satcat />
| orbit_reference    = [[Geocentric orbit|Geocentric]]
| orbit_regime       = [[Low Earth orbit]]
| orbit_periapsis    = {{convert|165|km|mi nmi|sp=us}}
| orbit_apoapsis     = {{convert|289|km|mi nmi|sp=us}}
| orbit_inclination  = 32.5&nbsp;degrees
| orbit_period       = 89.03&nbsp;minutes
| apsis              = gee
| crew_size          = 2
| crew_members       = {{Unbulleted list|[[James McDivitt|James A. McDivitt]]|[[Ed White (astronaut)|Edward H. White II]]}}
| crew_EVAs          = 1
| crew_EVA_duration  = 36 &nbsp;minutes
| crew_photo         = Gemini 4 crew portrait.jpg
| crew_photo_caption = White (left) and McDivitt (right)
| previous_mission   = [[Gemini 3]]
| next_mission       = [[Gemini 5]]
| programme          = [[Project Gemini]]
| insignia           = Gemini-4-logo.png
}}

'''Gemini 4''' (officially '''Gemini IV''')<ref name="titans">{{cite book
 | last1 = Hacker
 | first1 = Barton C.
 | last2 = Grimwood
 | first2 = James M.
 | title = On the Shoulders of Titans: A History of Project Gemini
 | chapter = Chapter 11 Pillars of Confidence
 | chapter-url = http://www.hq.nasa.gov/office/pao/History/SP-4203/ch11-1.htm
 | publisher = NASA
 | series = NASA History Series
 | volume = SP-4203
 | date = September 1974
 | page = 239
 | url = http://www.hq.nasa.gov/office/pao/History/SP-4203/toc.htm
 | access-date = 2013-09-26
 | archive-date = 2010-01-13
 | archive-url = https://web.archive.org/web/20100113132344/http://www.hq.nasa.gov/office/pao/History/SP-4203/toc.htm
 | url-status = dead
 }} With Gemini IV, NASA changed to Roman numerals for Gemini mission designations.</ref> was the second [[crewed spaceflight]] in [[NASA]]'s [[Project Gemini]], occurring in June 1965. It was the tenth crewed American spaceflight (including two [[X-15]] flights at altitudes exceeding {{convert|100|km|mi nmi|sp=us}}). [[Astronauts]] [[James McDivitt]] and [[Ed White (astronaut)|Ed White]] orbited the Earth 66 times in four days, making it the first US flight to approach the five-day flight of the [[Soviet Union|Soviet]] [[Vostok 5]]. The highlight of the mission was the first [[space walk]] by an American, during which White floated free outside the spacecraft, tethered to it, for approximately 23 minutes.

The flight also included the first attempt to make a [[space rendezvous]] as McDivitt attempted to maneuver his craft close to the [[Titan II GLV|Titan II]] [[upper stage]] which launched it into orbit, but this was not successful.

The flight was the first American flight to perform many scientific [[experiment]]s in space, including use of a [[sextant]] to investigate the use of [[celestial navigation]] for lunar flight in the [[Apollo program]].

==Crew==
{{Spaceflight crew
|terminology = Astronaut
|position1   = Command Pilot
|crew1_up    = [[James A. McDivitt]]
|flights1_up = First
|position2   = Pilot
|crew2_up    = [[Ed White (astronaut)|Edward H. White II]]
|flights2_up = Only
}}

===Backup crew===
{{Spaceflight crew
|terminology = Astronaut
|position1   = Command Pilot
|crew1_up    = [[Frank Borman|Frank F. Borman II]]{{sfn|Collins|2009|p=141}}
|position2   = Pilot
|crew2_up    = [[Jim Lovell|James A. Lovell Jr.]]{{sfn|Collins|2009|p=141}}
}}

===Support crew===
* [[Gus Grissom|Virgil I. "Gus" Grissom]] (Houston CAPCOM)
* [[Roger B. Chaffee]] (CAPCOM)
* [[Eugene Cernan]] (CAPCOM)

==Mission parameters==
*'''[[Mass]]:''' {{Convert|3570|kg|lb|abbr=on}}
*'''[[Perigee]] (insertion):''' {{Convert|165.8|km|mi nmi|abbr=on}}
*'''[[Apogee]] (insertion):''' {{Convert|293.7|km|mi nmi|abbr=on}}
*'''[[Orbital period|Period]]:''' 88.94&nbsp;min
*'''[[Inclination]]:''' 32.53°
*'''[[Perigee]] (last orbit):''' {{Convert|150|km|mi nmi|abbr=on}}
*'''[[Apogee]] (last orbit):''' {{Convert|232.8|km|mi nmi|abbr=on}}

===Spacewalk===
* '''Ed White''' - EVA - June 3, 1965
*'''Hatch opened''': 19:34 UTC
*'''Start EVA''': 19:39 UTC
*'''End EVA''': 20:02 UTC
*'''Duration''': 23 minutes
*'''Hatch closed''': 20:22 UTC<ref name=MissionReport>{{Cite journal |date=June 1965 |title=Gemini IV |url=https://ntrs.nasa.gov/api/citations/19670095754/downloads/19670095754.pdf |journal=Gemini Program Mission Report |publisher=NASA |issue=MSC-G-R-65-3 |page=4-2}}</ref>

==Objectives==
Gemini 4 would be the first multi-day space flight by the United States, designed to show that it was possible for humans to remain in [[outer space|space]] for extended lengths of time. The four-day, 66-[[orbital period|orbit]] flight<ref>
NASA reported that Gemini 4 made 62 ''revolutions'', defined as passes over Cape Kennedy's longitude ({{cite book |last=Gatland |first=Kenneth |title=Manned Spacecraft, Second Revision |publisher=Macmillan Publishing Co. |year=1976 |isbn=0-02-542820-9 |location=New York |page=168}}), the duration of which is longer than an ''orbit'' because of the Earth's eastward rotation. This is analogous to the difference between a [[Synodic day|solar day]] and a [[Sidereal time|sidereal day]] due to the Earth's revolution around the Sun.</ref> would approach but not break the five-day record set by the [[Soviet Union|Soviet]] [[Vostok&nbsp;5]] in June 1963. Subsequent Gemini flights would be longer, to prove endurance exceeding the time required to fly to the [[Moon]] and back.

A second objective was the first American [[extra-vehicular activity]] (EVA), known popularly as a "space walk". The first space walk had already been performed by Soviet [[Alexei Leonov]] on [[Voskhod&nbsp;2]] in March 1965. NASA moved up the spacewalk from the original schedule, to demonstrate that the US was gaining on the early lead taken by the Soviets in what was known as the [[Space Race]]. As late as 11 days before the scheduled June&nbsp;3 launch, newspapers were reporting NASA saying that it "had not yet determined whether White would be the first American astronaut to expose himself to the elements of space" and that "A decision might not be made until a day or two before launching."<ref>{{Cite web |date=May 22, 1965 |title=Gemini's 4-Day Space Probe Set For June 3 |url=https://news.google.com/newspapers?id=LdkLAAAAIBAJ&sjid=AlcDAAAAIBAJ&dq=gemini-4&pg=5389,3889421 |access-date= |website=The Evening Independent}}</ref>

A third objective was for Gemini 4 to attempt the first [[space rendezvous]], flying in formation with the spent second stage of its [[Titan II GLV|Titan&nbsp;II]] [[launch vehicle]].{{sfn|Collins|2009|p=139}}

==Flight==

===Launch===
[[File:GT-4 Launch - GPN-2000-001015.jpg|thumb|right|A [[Titan II GLV|Titan II]] launch vehicle lifts Gemini&nbsp;4 into orbit, June&nbsp;3, 1965.]]
Launched from [[Cape Canaveral Air Force Station Launch Complex 19|LC-19]] at [[Cape Canaveral Air Force Station|Cape Kennedy Air Force Station]], [[Florida]], Gemini&nbsp;4 was the first flight to be controlled by the new [[Christopher C. Kraft Jr. Mission Control Center|Mission Control Center]] at the [[Johnson Space Center|Manned Spacecraft Center]] in [[Houston, Texas]], which had to conduct three-shift operations due to the flight's long duration.<ref name="Shoulders of Titans">
{{cite book
  |last1=Hacker
  |first1=Barton C.
  |title=On the Shoulders of Titans: A History of Project Gemini
  |date=1977
  |publisher=NASA
  |location=Washington, D.C.
  |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19780012208_1978012208.pdf
  |archive-url=https://web.archive.org/web/20200503114750/http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19780012208.pdf
  |archive-date=3 May 2020
  |url-status=dead
  |access-date=22 January 2015}}</ref>

The broadcast of the launch was itself historic. For the first time an international audience, from 12 European nations, could watch the lift-off on live [[television]] via the [[Intelsat I|Early Bird]] [[satellite]]. [[Mass media|Press]] interest, due to the satellite broadcast and the new center in Houston, proved to be so high that NASA had to lease buildings to accommodate the 1,100 print and broadcast journalists who requested accreditation. Flight control shifted from Cape Kennedy to Houston as soon as the vehicle cleared the launch tower.

At liftoff, two roll transients caused by misalignment of the Titan first-stage engines occurred; these were quickly corrected by the autopilot. The fuel top-off umbilical failed to detach and was pulled loose when the booster had climbed about {{convert|27|ft|m|abbr=off|sp=us}}. A small oscillation in the pitch and yaw planes resulted from this. Performance of all launch vehicle systems was nearly nominal. Some modifications had been made to the guidance program on Gemini&nbsp;4's booster to produce a less lofted flight trajectory and a lower altitude at [[Booster (rocketry)|booster]] engine cut-off (BECO) than on Gemini&nbsp;3; these were generally successful despite a still somewhat lofted flight path. BECO occurred at T+152&nbsp;seconds, and second-stage engine cut-off (SECO) at T+333&nbsp;seconds. The spacecraft entered into an {{convert|161 by 283|km|mi nmi|abbr=on|sp=us}} orbit.<ref name=transcript>
{{Cite web
  |url= http://www.jsc.nasa.gov/history/mission_trans/GT04_TEC.PDF
  |archive-url=https://web.archive.org/web/20021124204813/http://www.jsc.nasa.gov/history/mission_trans/GT04_TEC.PDF
  |archive-date=24 November 2002
  |url-status=dead
  |title= Composite Air-to-ground and Onboard Voice Tape Transcription of the GT-4 Mission (U)
  |publisher= NASA
  |date= August 31, 1965
  |page= 3}}</ref>

===Rendezvous attempt===
On the first orbit, McDivitt attempted to [[Space rendezvous|rendezvous]] with the spent Titan second stage. This was unsuccessful for a number of reasons:
* NASA engineers had not yet worked out the idiosyncrasies of [[orbital mechanics]] involved in rendezvous, which are counter-intuitive. Simply thrusting the spacecraft toward the target changed its orbital altitude and velocity relative to the target. When McDivitt tried this, he found himself moving away and downward, as the retrograde thrust lowered his orbit, increasing his speed.<ref name="EA Gemini 4">{{Cite web |url=http://www.astronautix.com/g/gemini4.html |title=Gemini 4 |last=Wade |first=Mark |website=Encyclopedia Astronautica |url-status=dead |archive-url=https://web.archive.org/web/20190716093046/http://www.astronautix.com/g/gemini4.html |archive-date=July 16, 2019 |access-date=January 18, 2020}}</ref>
* The stage was dumping its residual propellant, causing it to move around in various directions relative to the Gemini.<ref name="mcdivittoh"/>
* There were only two running lights on the stage, which made it hard at times for McDivitt to determine its orientation. McDivitt concluded that a rendezvous target should have at least three lights.<ref name="mcdivittoh"/>
* There was no radar on board Gemini 4 to give a precise range to the target, so the astronauts had to rely on their visual depth perception to estimate the range, and this differed for the two men. Initially McDivitt estimated the distance at {{convert|400|-|500|ft|m}}, while White believed that it was closer ("a little over {{convert|200|ft|m}}"). At the worst point, McDivitt estimated it was about a half mile (800&nbsp;meters) away, while White's estimate was three-quarters of a mile (1200&nbsp;meters).<ref name=transcript/> McDivitt estimated that he was able to get as close as {{convert|200|ft|m}}, but now White's estimate was between {{convert|850|and|1000|ft|m}}.<ref name="EA Gemini 4"/>

After expending almost half his thruster fuel, McDivitt finally gave up, in order to concentrate on the more important EVA objective. (Rendezvous was finally achieved successfully by [[Wally Schirra]] commanding [[Gemini&nbsp;6A]] in December.) After the rendezvous attempt, Gemini&nbsp;4's orbit was {{convert|165.2 by 287.1|km|mi nmi|abbr=on|sp=us}}. Twenty-two hours into the mission, Mission Control estimated the orbit would decay to {{convert|150 by 232.8|km|mi nmi|abbr=on|sp=us}} at the end of 63 revolutions.<ref name=transcript/>

===Extra-vehicular activity (EVA)===
[[File:White Floats out the Open Hatch - GPN-2000-001407.jpg|thumb|White floats away from the open hatch, towards the nose of the spacecraft at the beginning of the EVA]]
Originally planned for the second revolution, the astronauts postponed the EVA until the third after McDivitt decided that White, following the stress of the launch and the failed rendezvous, looked tired and hot. After a rest, the pair finished performing the checklist for the EVA. Flying over [[Carnarvon, Western Australia|Carnarvon, Australia]], they began to depressurize the cabin. Over [[Hawaii]], White pulled the handle to open his hatch, but the latches failed to move.

Fortunately, McDivitt knew what the problem was, because the hatch had failed to close in a [[vacuum chamber]] test on the ground, after which McDivitt worked with a technician to see what the cause was. A spring, which forced gears to engage in the mechanism, had failed to compress, and McDivitt got to see how the mechanism worked. In flight, he was able to help White get it open and thought that he could get it to latch again.<ref name=mcdivittoh/>

There were communication problems during the spacewalk. Gemini spacecraft were the first to use a [[voice-operated switch]] (known as VOX) on the astronaut's microphones, but McDivitt soon realized that his VOX circuit was not working properly; he could only hear the [[Flight controller#Spacecraft communicator (CAPCOM)|Capsule Communicator (CAPCOM)]] in the [[push-to-talk]] setting, but not on VOX (though both astronauts could be heard by each other and the ground). Plus, while outside the spacecraft, White was unable to receive transmissions from the ground and had to have all messages relayed through McDivitt. McDivitt must have switched to the VOX setting somewhere around the time White was exiting the spacecraft, because at that point, for most of the EVA, neither he nor White responded either to the Hawaii CAPCOM, or to the Houston CAPCOM, [[Gus Grissom]]. Grissom tried to talk to Gemini&nbsp;4 a total of 40&nbsp;times in 13&nbsp;minutes before he got a response.<ref name=transcript/>

Tied to a tether, White floated out of the spacecraft, using a [[Hand-Held Maneuvering Unit]] (informally called a "zip gun") which expelled pressurized oxygen to provide thrust for controlling his travel. He went {{convert|15|ft|m|order=flip|sp=us}} out and began to experiment with maneuvering. He found it easy, especially the pitch and yaw, although he thought the roll would use too much gas. He maneuvered around the spacecraft while McDivitt took photographs. White enjoyed the experience, but exhausted the HHMU gas sooner than he would have liked.

White was running up against two factors which constrained the time for his EVA: loss of signal from the [[Naval Air Station Bermuda|Bermuda tracking station]] and crossing the [[terminator (solar)|solar terminator]]. The [[flight controller]]s were becoming increasingly frustrated with their inability to remind White of the time constraint, because they didn't want the first EVA to be performed in darkness or out of communication with Earth. Finally McDivitt decided to take his microphone off of VOX:<ref name=transcript/>
{{Blockquote|
McDivitt, to White: I'm going out to PUSH-TO-TALK and see what the Flight Director has got to say.

[[Flight Director]] [[Christopher C. Kraft Jr.|Chris Kraft]], to Grissom: The flight director says, get back in! (Kraft was not on the air-to-ground loop with the astronauts.)

McDivitt: Gus, this is Jim. Got any message for us?

Grissom: Gemini 4, get back in!

McDivitt: Okay. ... (to White): ... They want you to come back in now.
}}

White tried to use taking more pictures as an excuse to stay out longer, and McDivitt had to coax him in. He finally came back in after a total of approximately 23&nbsp;minutes, almost 10&nbsp;minutes later than was planned.<ref name=MissionReport/> He said: "It's the saddest moment of my life."<ref name=transcript/> By the time he got in, the spacecraft had entered darkness.<ref name=mcdivittoh/>

The hatch proved to be as stubborn to relatch as it was to open. This would have been disastrous, resulting in both men's deaths on reentry. McDivitt was able to fix the mechanism once again, so White could close it, about 20&nbsp;minutes after he got in.<ref name=MissionReport/> The mission plan called for opening the hatch again to throw out White's now-unnecessary EVA equipment, but McDivitt elected not to do this, instead keeping the unnecessary equipment on board for the rest of the flight.<ref name="mcdivittoh">{{Cite interview |last=McDivitt |first=James A. |interviewer=Doug Ward |title=Oral History Transcript |url=http://www.jsc.nasa.gov/history/oral_histories/McDivittJA/JAM_6-29-99.pdf |archive-url=https://web.archive.org/web/20110622104517/http://www.jsc.nasa.gov/history/oral_histories/McDivittJA/JAM_6-29-99.pdf |archive-date=2011-06-22 |url-status=dead |place=Elk Lake, Michigan |date=29 June 1999}}</ref>

They powered down the spacecraft's maneuvering system, intending to drift for the next two-and-a-half days to conserve the remaining fuel. They also intended to sleep alternate four-hour periods, but this turned out to be extremely difficult with the constant radio communications and the small cabin, about the size of the front seats of a [[compact car]].

White's 20-minute space walk was the mission's highlight, with McDivitt's photographs being published worldwide. These also showed White wearing an [[Omega Speedmaster]] chronograph watch on his spacesuit sleeve, one of two makes which had been approved by NASA for space use following extensive tests. Omega were unaware of these tests or the fact that its product was going to be used in space, until the photos. The model worn during the spacewalk is now known as the "Ed&nbsp;White" by watch collectors.

===Experiments===
Eleven [[experiment]]s were carried on the [[spacecraft]]:
*Experiment D-8 used five dosimeters to measure the radiation in the spacecraft environment. Of particular interest was the [[South Atlantic Anomaly]].
*Experiment D-9 was an experiment in simple spacecraft navigation where the crew used a [[sextant]] to measure their position using the stars. The objective was to investigate the feasibility of using this technique for lunar flights on the [[Apollo program]].
*Experiments S-5 and S-6 were both photography experiments where they used a 70-[[millimeter]] [[Hasselblad]] camera to photograph the weather and terrain below them.
*There were two medical experiments: M-3 and M-4. The first was a [[bungee cord]] that the crew used for exercise. They said, after the mission, that this got harder as the mission went on, though this may have been due to a lack of sleep. The second was the phonocardiogram experiment, which had sensors attached to their bodies that measured heartbeat rates, especially during liftoff, EVA, and reentry.

There were four engineering experiments:
*MSC-1 measured the [[electrostatic charge]] in the spacecraft,
*MSC-2 was a proton-electron [[spectrometer]],
*MSC-3 was a tri-axis [[magnetometer]] and
*MSC-10 involved the crew photographing the red-blue Earth limb.

Photographs were taken over the Middle East and the southwestern United States; several air fields indicated on charts were identified.

The crew had 16 freeze-dried meals and ate all but one of them. As they lacked any means of measuring water intake, they attempted to minimize consumption of it and also reported high amounts of gas bubbles in the water from the water dispenser. They experienced a degree of eye, nose, and throat irritation early in the flight and post-landing. This was attributed to ammonia fumes from the flame retardant used in the cabin, which was changed to a different material on subsequent flights.

===Reentry===
[[File:White and McDivitt Talk to President - GPN-2000-001341.jpg|thumb|White (l) and McDivitt being congratulated by President [[Lyndon B.&nbsp;Johnson]] by telephone aboard the aircraft carrier USS ''Wasp'']]
The computer failed on the 48th revolution when McDivitt tried to update it for reentry. It would not turn off and eventually stopped working altogether. This was unfortunate for [[IBM]], which had just put an advertisement suggesting that its computers were so reliable that even NASA used them.<ref>{{cite web
| url=https://www.ibm.com/ibm/history/exhibits/vintage/vintage_4506VV9013A.html
| title=System/360 Model 20 (A) (1964)
| work=IBM Archives
| date=23 January 2003
| publisher=[[IBM]]
| access-date=2019-04-26}}</ref> The computer failure meant that the capsule would not be able to perform a [[control theory#Open-loop and closed-loop (feedback) control|closed-loop]] lifting reentry as planned. IBM were unable to duplicate the failure on the ground but they installed a manual override switch on subsequent Gemini missions. It was the only Gemini mission to experience a computer failure.

Reentry came on the 62nd revolution. An open-loop rolling reentry (as used in Mercury) had to be used because of the computer failure.<ref name="mcdivittoh"/> The astronauts began rolling the spacecraft at {{convert|120|km|mi nmi|sp=us}} altitude to increase its stability. They started slowing the roll rate at {{convert|89,000|ft|m|order=flip|sp=us}} and stopped it by {{convert|39,000|ft|m|order=flip|sp=us}}. The [[drogue parachute]] deployed shortly after this, and the main deployed at {{convert|10,600|ft|m|order=flip|sp=us}}. A malfunctioning thruster caused the roll to be much faster than planned,<ref name="mcdivittoh"/> and the landing was rough. Neither of the crew encountered any problems, however, contrary to NASA doctors' concerns about their landing upright{{snd}} as opposed to on their backs, as in Mercury{{snd}} after four days in space.<ref name="mcdivittoh"/> Even though they landed {{convert|80|km|mi nmi|abbr=on|sp=us}} short of the intended landing target, some ships had already started steaming to the touchdown point, and a helicopter was able to see them land. The prime recovery ship was {{USS|Wasp|CV-18|6}}. The recovery was supported by 10,249 U.S. Department of Defense personnel, 134 aircraft, and 26 ships.

Postflight medical examination found the astronauts to be in good health, and no significant physiological changes were found.

==Insignia==
[[File:Gemini 4 Flown Silver Fliteline Medallion.jpg|thumb|Gemini 4 space-flown [[NASA space-flown Robbins medallions of the Apollo missions#Gemini mission space-flown Fliteline medallions|Fliteline Medallion]]]]
Gemini 4's crew originally intended to call their spacecraft ''American Eagle'', but this was rejected after NASA management issued a memo saying that they did not want a repeat performance of the previous mission, on which [[Gus Grissom#Spacecraft naming|Gus Grissom]] had named his spacecraft ''[[Molly Brown]]''.{{sfn|Collins|2009|pp=138-139}}

The callsign for the mission became simply ''Gemini 4''. There was no patch flown on the crew's suits, although the one shown here was created after the mission and is on display in McDivitt's museum. Since McDivitt and White were prohibited from naming their spacecraft, they decided to put the [[Flag of the United States|American flag]] on their suits, the first astronauts to do so, although Soviet crews wore the Cyrillic "СССР" on their spacesuit helmets. Previous astronauts had only had the NASA insignia and a strip with their name on their suits.

[[File:US Space Walk 1967 Issue-5c.jpg|thumb|alt=US 5 cent postage stamp design featuring White tethered to the Gemini spacecraft in Earth orbit |[[U.S. Space Exploration History on U.S. Stamps|Accomplishments in Space Commemorative Issue of 1967]]]]
The flight was commemorated on a pair of US postage stamps in 1967.
{{-}}

==Spacecraft location==
[[File:Gemini 4 National Air and Space Museum 2018.tif|thumb|The Gemini 4 capsule on display at the National Air and Space Museum.]]
The spacecraft is on display at the [[Steven F. Udvar-Hazy Center]], [[Chantilly, Virginia]]

== See also ==
{{Portal|Spaceflight}}
* [[Extra-vehicular activity]]
* [[List of spacewalks]]
* [[Splashdown (spacecraft landing)|Splashdown]]

==References==
{{Include-NASA}}
{{Reflist}}

==Bibliography==
*{{cite book |last = Collins |first = Michael |others=Lindbergh, Charles (foreword) |year = 2009 |title = [[Carrying the Fire: An Astronaut's Journeys]] |publisher = Cooper Square Press |isbn = 9780374531942}}

==External links==
{{Commons category|Gemini 4}}
*[https://www.hq.nasa.gov/office/pao/History/SP-4203/ch11-2.htm Gemini 4 report from the NASA History Office] {{Webarchive|url=https://web.archive.org/web/20190714132641/https://www.hq.nasa.gov/office/pao/History/SP-4203/ch11-2.htm |date=2019-07-14 }}
*[http://www.genedorr.com/patches/Intro.html Spaceflight Mission Patches website]
*[https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1965-043A NASA NSSDC spacecraft details]
*[https://web.archive.org/web/20090621232414/https://mira.hq.nasa.gov/history/ws/hdmshrc/all/main/DDD/39984.pdf NASA Gemini 4 press kit - May 21, 1965]
*[https://www.youtube.com/watch?v=lkhIFNS-KVM&list=PLZ4LzWgVGYi0n0VGYv-zBX9Ou3S3kphQb&index=5 "GEMINI 4 - Ed White Spacewalk- Dual Camera, Real Speed, Restored Audio"] on YouTube
*{{Internet Archive short film | four_days_of_gemini_4 | Four Days of Gemini 4}}
*[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19670095754.pdf Gemini Program Mission Report - Gemini IV] from the [https://ntrs.nasa.gov/search.jsp NASA Technical Reports Server]

{{Gemini program}}
{{Orbital launches in 1965}}
{{Authority control}}

{{DEFAULTSORT:Gemini 04}}
[[Category:Human spaceflights]]
[[Category:Project Gemini missions]]
[[Category:1965 in the United States]]
[[Category:Extravehicular activity]]
[[Category:Spacecraft launched in 1965]]
[[Category:Spacecraft launched by Titan rockets]]
[[Category:Spacecraft which reentered in 1965]]
[[Category:June 1965]]
[[Category:Ed White (astronaut)]]
[[Category:James McDivitt]]
[[Category:Successful space missions]]