If some aims had to be postponed, however, they were balanced by some worthwhile gains. Extravehicular activity (EVA) emerged as a new feature of Gemini IV, and Gemini V expanded to an eight-day mission that included practice with the rendezvous evaluation pod. The new Mission Control Center in Houston assumed flight control duties for Gemini IV,1 taking over that job from the former control center at Cape Kennedy. Only two months were to elapse between Gemini IV and V, a sign of the progress that NASA was making toward putting space flight on something like a routine basis. Perhaps most important, these two missions set Project Gemini firmly on the path to reaching its major objectives, sweeping aside fears that astronauts might not be able to survive long periods of weightlessness in space and holding out the promise that rendezvous could soon be achieved.
NASA announced the crews for Gemini IV on 27 July 1964, and two days later James A. McDivitt and Edward H. White II, along with  their backups, Frank Borman and James A. Lovell, Jr., talked with reporters in Houston. McDivitt and White, aged 35 and 34, had known each other since college and had been in the same class at the Air Force test pilot school. Borman and Lovell, both 36, first met when they were undergoing testing by NASA. Borman was an Air Force officer and Lovell was in the Navy. All four men were second generation astronauts, part of the group selected by NASA in September 1962.2
Their first task after the announcement was to review the status of the spacecraft and booster assigned to their mission. Spacecraft 4 was still being built in St. Louis, with some problems caused by a shortage of parts.3 In Baltimore, GLV-4 was also in the process of being assembled.4 After that quick look, the crewmen spent the next five weeks cleaning up work left over from their former assignments. Mission training had to wait until the end of November, when Gemini Simulator 2 became operational in Houston.5
Meanwhile, McDivitt and his crewmates, knowing that EVA might be included in Gemini IV, seized every chance to press the case for making it part of their mission. This persistence won NASA management's consent to provide the special space suits that EVA required. The astronauts were not merely chauffeurs; their role in the program went far beyond that of the normal test pilot in determining what was to be done and when. Without the strong pressure from the Gemini IV crewmen, the G4C suit might have been too far down the line to have permitted NASA's late decision to include EVA in the fourth mission.6 That decision was not, however, quite so late as it appeared.
When Cosmonaut Aleksey A. Leonov walked in space on 18 March 1965, during the Voskhod II mission, he revived press complaints that America lagged in the space race and raised fears that a year might pass before a Gemini astronaut matched the Russian's feat. When, a little more than two months later, NASA announced that White would step into space on the next Gemini flight and use a "zip gun" to propel himself, most space watchers merely assumed that NASA was still trying to keep up with its Soviet rival.7 This may have been true as far as timing was concerned; but EVA had been a part of Gemini thinking almost from the beginning, and studies had begun as early as 1962.8 The road from study to a place in the flight plan, however, was a rocky one.
Even the public linking of EVA with Gemini IV preceded Voskhod II by nearly eight months. At the same press conference in July 1964 where the Gemini IV crewmen took their bow, Gemini Deputy Manager Kenneth Kleinknecht had said one of the crew might open the hatch and stick his head outside during the mission. McDivitt was surprised at how little notice newsmen took of Kleinknecht's statement.9  At that point, it was still far from certain that even a simple hatch opening would be permitted in Gemini IV. The key questions involved equipment and training.
Gemini IV first appeared as the program's lead-off EVA mission in a "Program Plan for Gemini Extravehicular Operation," during January 1964. Management response was cool, largely because equipment development was only beginning.10 During the next few months, however, matters improved. The AiResearch Manufacturing Company was awarded a contract for the extravehicular chestpack, the David Clark Company was sent specifications for the extravehicular suit, and McDonnell was authorized to begin an EVA design that was eventually applied to Spacecraft 6.11
After Kleinknecht's largely ignored statement in July on standup EVA plans for Gemini IV, the issue continued to be debated within NASA. MSC's Engineering and Development Directorate, and its Crew Systems Division, in particular, opposed any EVA in Gemini missions until crews faced some realistic simulations on the ground.12 The scheduled altitude chamber tests of Spacecraft 3 in November 1964 offered a good chance to meet that demand. Gus Grissom and John Young wanted to depressurize the cabin during their training for Gemini III and open the hatch at a simulated altitude of 46,000 meters. Selling this idea to McDonnell was not easy. McDonnell, as Young later remarked, "certainly didn't want to take the chance of bagging a couple of astronauts in the altitude chamber," and NASA was none too happy about "putting guys in vacuums with nothing between them but that little old lady from Worcester, Massachusetts [the seamstress at the David Clark Company], and her glue pot and that suit."13
Kleinknecht argued that "if we can't do it in the altitude chamber, then we haven't any business doing it 100 miles [160 kilometers] in space." GPO told McDonnell to "include at least one complete depressurization, hatch opening and closing, and repressurization cycle at 40,000 feet [12,000 meters] altitude conditions in each spacecraft manned altitude chamber test commencing with spacecraft 3." The first try at EVA practice left something to be desired, Young recalled, when "we opened the hatch and [then] we couldn't close it." But the three-orbit Gemini III mission was really too short for EVA anyway, and GPO focused its efforts on Gemini IV.14
Plans were firmer by the start of 1965, and the Gemini IV crews began training for EVA.15 Nevertheless, the decision of whether to include EVA in the mission was far from settled, either at MSC or NASA Headquarters. MSC Director Gilruth did approve altitude chamber tests for the crew, but only on 12 March 1965, less than a week before Leonov's space walk.16 That feat spurred new efforts to get extravehicular activity into an early Gemini mission. With the flight of Gemini III just a week away, that meant Gemini IV.  During that week between Voskhod II and Gemini III, Gilruth and Deputy Director George Low had their first look at a "hand held maneuvering unit," which had been designed and built without fanfare in MSC's Crew Systems Division. That device, along with a display of the progress with other EVA equipment, brought the Center's top management solidly behind trying for EVA in its second manned mission.17
The hardware still needed to be qualified. Gilruth gave the job to Crew Systems with a warning to keep the work as quiet as possible, perhaps to avoid any appearance of too-hasty reflex to Russian accomplishments. A model spacecraft was quickly installed in MSC's 6-meter vacuum chamber, and preliminary testing was begun.18 By the end of April, the vacuum chamber was ready for full-scale EVA simulation, and Flight Operations people had come into the picture to begin working out techniques for handling EVA as a flight control matter.19
But NASA Headquarters had yet to be won over. Manned space flight chief George Mueller learned about the MSC plans when he visited Houston on 3 April; his response was lukewarm, perhaps because of the still unqualified status of the hardware. Although he offered no encouragement, Mueller was not inclined to order a halt, and MSC went ahead with its plans. On 14 May, when Gilruth arranged an EVA demonstration for Associate Administrator Robert Seamans, he won a high-ranking ally. Seamans promised to discuss MSC's new venture with Administrator James Webb and his deputy, Hugh Dryden.20
The next day, Mathews and three of his men were in Washington for another attempt to convince Mueller that EVA belonged on Gemini IV. Mueller's crucial question was how EVA, not officially scheduled until Gemini VI, could be moved up two flights; the answer was simply that everything was ready: all EVA gear was qualified, or nearly so, and the crew was trained. After he got back to Houston, Mathews called Mueller on 19 May to report that the last piece of EVA equipment was now flight ready.21
Seamans, as he had promised, did describe the EVA plan for Gemini IV to Webb and Dryden. Webb liked it, but Dryden objected strongly; he thought it smacked too much of a reaction to what the Russians had done. At Webb's request, Seamans drew up a brief stating the reasons for putting EVA on the current Gemini mission, which concluded: "The hardware for extravehicular activity is flight qualified and the astronauts are trained for this operation. Since extravehicular activity is a primary goal for the Gemini program, it is recommended that this activity should be included in Gemini IV." Webb gave the paper to Dryden. On 25 May, Dryden called Seamans to his office and, without saying a word, handed him a document. It was the case Seamans had made for EVA; scribbled on one corner was "Approved, after discussing w. Dryden [signed], J. E. Webb, 5-25-65."22
There was still a question about how and when to make public the plans for EVA.  MSC opinion was divided. Some favored breaking the news after the fact, some while EVA was in progress, and others at the premission press conference 24 hours before launch. In April, MSC decided to announce it at the press briefing, if it were approved. Seamans, however, rejected that scheme as incompatible with NASA's historic policy of openness on plans for manned launches and ordered EVA material to be included in the press kit for Gemini IV. When the kit appeared on 21 May it contained a one-page discussion of "Possible Extravehicular Activity." On 25 May, the same day EVA was approved, the press was informed that White would leave his spacecraft and walk in space.23
One reason for Mueller's resistance to EVA was a plan to combine it with rendezvous. Gemini IV was scheduled to rendezvous with the second stage of its booster in orbit, and White could then use his zip gun to propel himself over near the floating stage. This idea was also a latecomer to Gemini. The rendezvous evaluation pod scheduled for the fourth mission had been forced out in January 1964, when problems with the radar design made it unlikely that that crucial equipment would be available in time.24 A bit of joking by Gordon Cooper over the communications link to Grissom in Gemini III on 23 March 1965, suggested another kind of practice rendezvous.
Cooper: I have a time for when you'll be nearest the booster [second stage]. Would you like to have that so that you can look for it?Gilruth and Low overheard the exchange and thought it sounded like a pretty good idea. Low checked with GPO and Crew Systems and got an enthusiastic response. With Gilruth's wholehearted support, in May 1965 stationkeeping joined EVA as part of the Gemini IV flight plan. The spacecraft would match velocities with the orbiting second stage a relatively short distance away in the same orbital plane and maintain that position for a time. Grissom had maneuvered "Molly Brown," but he had no target. Closing in on a specific object (or point) in space was much more ambitious, especially since McDivitt and White would have to depend on their eyes to track the target, since the rendezvous radar was still unavailable. Martin did install flashing lights on the GLV-4 second stage to help the crew find it.26 McDivitt and White had still another handicap. There was simply no way for them to train on the ground for stationkeeping - neither the Cape nor the Houston  simulator was designed for this task. McDonnell came through by rigging equipment to provide a simulated view of the target against a star background. McDivitt and Borman spent half a day in St. Louis practicing optical rendezvous, but it was makeshift at best.27
Cooper: Roger. 02 plus zero eight plus five two will be dead ahead at an elevation of plus eight zero degrees at one niner miles. This will be just prior to darkness. It should be very bright. Proceed to see if you can rendezvous.25
One other major problem confronted Gemini IV planners, the physiological consequences of a prolonged stay in orbit and of EVA. Charles A. Berry, medical director of the Gemini program, was troubled by the leap of faith implied by the Gemini flight schedule of April 1963, which followed the three-orbit Gemini III with the seven-day Gemini IV. He wanted the length of the mission reduced by half, and trouble with fuel-cell development might come to his aid. If batteries had to be used, the mission could not last more than four days. In August 1964, Mathews reported to NASA Headquarters that Gemini IV would be a four-day mission, not only for medical reasons but also because the fuel cell would have to be replaced by batteries.28
Berry was not happy even with a four-day mission. Cardiovascular problems had cropped up in the last two Mercury missions, and every physiologist he met made the same comment about Gemini IV, or so it later seemed:"[Don't you] really know that these guys [are] going to stand up and pass out and might, indeed, die from this flight?"29 The astronauts would be subjected to much the same kind of physiological strain as that imposed by prolonged bedrest followed by vigorous activity. After their bodies had been deconditioned by days of weightless flight, they had to face high reentry g forces, which might well cause them to faint. If an astronaut fainted during or after landing, he would be held upright by his harness, forcing a perhaps already overtaxed heart to work even harder pumping blood to his head. But astronauts were not bed patients; besides using their muscles for flight tasks they would have been exercising with a bungee cord, a device adapted from the nylon strap and handle of a spear gun that required a force of 300 newtons (70 pounds) to extend it 30 centimeters (12 inches).30
EVA added still another medical concern, the disorientation and motion sickness that might overtake a floating astronaut unable to distinguish "up" from "down." Leonov, according to Russian reports early in May 1965, had trouble with his vision and orientation "when he didn't see the spacecraft." Berry, McDivitt, and White studied a filmed interview, with scenes of the space walk, which clearly showed Leonov using numerous reference points - the Sun, the spacecraft, Earth - to maintain orientation. That seemed to be the best answer, the astronaut making sure he knew where he was at all times in relation to the spacecraft.31
From a medical viewpoint, then, some degree of tension marked the approach of the Gemini IV mission. This was, after all, the first four-day flight by Americans, and the Russians were airing their fears  of disorientation and physiological dangers at numerous medical conferences. But the crew was trained, and everything that could be foreseen had been considered. There was nothing to do now but wait to see what happened.32
* With Gemini IV, NASA changed to Roman numerals for Gemini mission designations. The text will hereafter use Roman numerals for all Gemini missions.
1 NASA News Release No. 62-172, "NASA Mission Control Center to Be at Houston, Texas," 20 July 1962; "News Conference. Manned Spacecraft Center Mission Control Announcement," 9 April 1965.
2 "McDivitt, White Named Prime Crew for Second Manned Gemini Flight," MSC Space News Roundup, 5 Aug. 1964; "News Conference, GT-4 Crew Selection," 29 July 1964.
3 André J. Meyer, Jr., notes on NASA/MAC management meeting, 17 July 1964, p. 3; "NASA/MAC Management Meeting 16 October 1964," p. 6.
4 James M. Grimwood and Barton C. Hacker, Project Gemini Technology and Operations: A Chronology, NASA SP-4002 (Washington, 1969), p. 277.
5 MSC Weekly Activity Report for Office of Assoc. Adm., Manned Space Flight, 6-12 Dec. 1964, p. 3; James A. McDivitt, interview, Houston, 7 April 1967.
6 Reginald M. Machell, interview, Houston, 18 April 1967; TWX, Charles W. Mathews to McDonnell, Attn: Walter F. Burke, "Contract NAS 9-170, Astronaut Harness Fit and Contouring," 14 May 1965.
7 Union of Soviet Socialist Republics, USSR Aero Sports Federation, "Records File on the First in the World Space Flight in the Voskhod-2 Spacecraft Including the Mans Emerging into Outer Space, March 18-19, 1965. The Crew of the Spacecraft Consists of the USSR Citizens: 1. Pilot-Cosmonaut Pavel Ivanovich Belyayev, Spacecraft Commander; 2. Pilot-Cosmonaut Alexei Arkhipovich Leonov, Second Pilot," Moscow, 1965; "Space Walk Is Still Year Away for U.S.," The Evening Star, Washington, 18 March 1965; "Long Stride into Space," The New York Herald Tribune, 19 March 1965; "Over and Out," The Sun, Baltimore, 19 March 1965; Earl Ubell, "Gemini," New York Herald Tribune, 21 March 1965; Wayne Thomis, "The Space Race: How Russia and U.S. Stand Now;" Chicago Tribune, 28 March 1965; Marvin Miles, "Open-Hatch Space Test Undecided," Los Angeles Times, 18 April 1965; William Hines, "New Gemini Crew on TV, Tell of 4-Day-Flight Plans," The Evening Star, Washington, 30 April 1965; Frank Macomber, "Stroll in Space Definite for U.S. Gemini Astronaut, The San Diego Union, 25 April 1965; Jim Maloney, "Shepard on Job 4 Years after Flight," The Houston Post, 10 May 1965; Evert Clark, "4-Day Gemini Trip Is Set for June 3: Opening of Hatch on 2-Man Flight Still Undecided," The New York Times, 22 May 1965; "American Space Walk," The Evening Star, Washington, 28 May 1965.
8 "Abstract of Meeting on Crew Support Systems, May 10-11, 1962," 14 May 1962; TWX, Mathews to Burke, "Contract NAS 9-170; Provision of Extra Vehicular Operations Capability in Spacecraft Number 2 and Up," GPO-50633, 28 Feb. 1963.
9 "GT-4 Crew Selection"; Astronautics and Aeronautics, 1964; Chronology on Science, Technology, and Policy, NASA SP-4005 (Washington, 1965), p. 265; "Gemini Astronauts May Stick Heads out Craft's Window," The Washington Post, 30 July 1964; McDivitt interview.
10 "Program Plan for Gemini Extravehicular Operation," [GPO], 31 Jan. 1964; Warren Gillespie, Jr., acting secretary, "Minutes of InFlight Scientific Experiments Coordination Panel, January 16, 1964," p. 5; Machell interview.
11 MSC Consolidated Activity Report for Office of the Assoc. Adm., Manned Space Flight, 19 Jan. - l5 Feb. 1964, p. 39; letter, Mathews to Burke, "Contract NAS 9-170, spacecraft provisions for Gemini extravehicular operation," GP-03573, 15 April 1964; letter, Mathews to Burke, GS-64025, 14 May 1965; "Abstract of Meeting on Extravehicular Activity, July 14, 1964," 27 July 1964; Meyer, notes on GPO staff meeting, 1 April 1964.
12 Robert A. Dittman, "Gemini Program Office Staff Meeting Minutes, October 6, 1964," p. 3.
13 John W. Young, interview, Houston, 28 April 1967.
14 Kenneth S. Kleinknecht, interview, Houston,5 Dec.1966; George M. Low, interview, Houston, 7 Feb. 1967; TWX, Mathews to McDonnell, Attn: Burke, GP-51575, 12 Nov. 1964; Young interview.
15 Memo, Duncan R. Collins to Mgr., GPO, "Review of effectivity of Spacecraft 6 for extravehicular operation," GS-04151, 14 Jan. 1965; Project Gemini Quarterly Status Report No. 12, for period ending 28 Feb. 1965, p. 43.
16 TWX, Mathews to McDonnell, Attn: Burke, GP-51747, 10 Feb-1965; memo, Robert L. Frost for record, "Gemini Spacecraft 4 altitude chamber test plan briefing," GS-64006, 25 March 1965; Weekly Activity Report, 21-27 March 1965, p. 1.
17 Low interview; Larry E. Bell, interview, Houston, 10 Sept. 1968; letter, Paul E. Purser to John W. Macy, 18 Aug.1965, with enclosure, David L. Schwartz, "EVA - The Story of a Team Effort by Civil Service Employees," n.d.
18 Schwartz, "A Team Effort."
19 Ibid.; Eugene F. Kranz, interview, Houston, 28 April 1967.
20 Low interview; Robert R. Gilruth, interview, Houston, 21 March 1968; William C. Schneider, interview, Washington, 23 Jan. 1967.
21 Bell interview; Quarterly Activity Report for Office of the Assoc. Adm., Manned Space Flight, for period ending 30 April 1965, p. 38; Quarterly Activity Report, for period ending 31 July 1965, p. 31; Quarterly Status Report No. 13, for period ending 31 May 1965, pp. 9, 10.
22 Robert C. Seamans, Jr., to William D. Putnam, comments on narrative history of Gemini, comment edition, 3 April 1969; memo, Seamans to Adm., "Extra Vehicular Activity for Gemini IV," 24 May 1965, with Webbs signed approval, 25 May 1965.
23 Bell interview; Paul P. Haney, interview, Houston, 16 Sept. 1968; NASA Release No. 65-158, "Project: Gemini 4," press kit, for release 21 May 1965, p. 5; William Hines, "NASA Opens Open Secret on Plans for Gemini 4 Flight," The Evening Star, Washington, 21 May 1965; Evert Clark, "U.S. Space Walk Planned in June," The New York Times, 25 May 1965; "Press Conference on Extravehicular Activity," 25 May 1965.
24 Low interview; Meyer, notes on GPO staff meeting, 2 Jan. 1964; letter, Low to MSC, Attn: Mathews, "Configuration of Gemini Spacecrafts #2, 3, and 4," 4 Jan. 1964.
25 "[Gemini III] Air to Ground Transmission," GT-3 News Center, 23 March 1965, p. 14.
26 Low interview; Howard W. Tindall, Jr., interview, Houston, 16 Dec. 1966; Wyendell B. Evans, telephone interview, 1 Oct. 1968; TWXs, Mathews to SSD, Attn: Richard C. Dineen, GV-12035, 9 April, and GV-12084, 25 May 1965.
27 Robert L. Sharp, interview, St. Louis, 14 April 1966; "Gemini Program Mission Report, Gemini IV," MSC-G-R-65-3, July 1965, p. 7 -14.
28 Charles A. Berry, interview, Houston, 18 March 1968; Quarterly Status Reports: No. 5, for period ending 31 May 1965, pp. 50-51; No. 7, for period ending 30 Nov. 1963, p. 79; No. 10, for period ending 31 Aug. 1964, pp. 3,59; Consolidated Activity Report 19 Jan. - 15 Feb.1964, p. 17; memo, Mathews to Gemini Procurement, Attn: James I. Brownlee, "Contract NAS 9-170; Gemini, installation of batteries in Spacecraft 4, CCP No. 20," GP-03532, 20 March 1964; Eldon W. Hall and Vearl N. Huff, interview, Washington, 24 Jan. 1967; Raymond D. Hill, Jr., interview, Titusville, Fla., 23 May 1967; Kleinknecht interview.
29 Berry interview.
30 James Waggoner, interview, Los Angeles,8 July 1966; Lawrence F. Dietlein, "Experiment M-3, Inflight Exerciser on Gemini IV," in "Manned Space Flight Experiments Symposium: Gemini Missions III and IV," presented in Washington, 18-19 Oct. 1965, pp. 41-48; Dietlein, interview, Houston, 22 March 1968.
31 Transcribed segments of Leonov's space walk during Voskhod II and at postflight conferences in Perm, Baykonur, and Moscow, however, do not mention disorientation. Astronautics and Aeronautics, 1965: Chronology on Science, Technology, and Policy, NASA SP-4006 (Washington, 1966), pp. 225-26; "Continued Reportage on Flight of Voskhod 2," 22 March 1965 (14 pages), and "Reportage on Moscow Welcome to Cosmonauts," 23 March 1965 (13 pages), U.S.S.R. National Affairs; Berry interview.
32 Memo, M. Scott Carpenter to dist., "Cosmonaut Training," 24 Nov. 1964; Margaret M. Jackson and M/sgt. C. W. Sears, "The Effect of Weightlessness upon the Normal Nystagmic Reaction," Aerospace Medical Association, 36th Annual Scientific Meeting, New York, 26-29 April 1965, preprint of scientific program, pp. 138-39.