Spokesmen for North American and MSC met in Houston 27-28 March to discuss the options. Telephones in GPO, in the Gemini Procurement Office, and in North American were busy over the next two weeks as the main features of a revised test program were argued, talked out, and settled. The key decision was to divide the flight sequence in half and work through the problems of each phase separately before trying to demonstrate a complete flight from deployment through landing.56
Spreading the wing in flight was still the crucial problem, and it was to be tackled with the two full-scale test vehicles. The new test plan, however, was simpler than the old. As the vehicle dropped from a high-flying aircraft, its wing would inflate and deploy to convert its fall into a glide down to 3,000 meters. That ended the test sequence. Explosive charges would sever the cables that suspended the test vehicle from the wing, and the now wingless vehicle would descend to Earth beneath a large parachute. The rest of the flight sequence, gliding from 3,000 meters to a landing, was to be studied with two tow-test vehicles, modified versions of the paraglider trainer. Towed by a helicopter to the proper altitude and then released, this vehicle would be flown by a pilot down to the California desert. In the final stage of the program, Gemini static articles would be fitted with standard paraglider gear and flown through the complete flight sequence from deployment to landing.57
If everything went according to plan, the paraglider landing system could be ready for the seventh Gemini spacecraft. By the time McDonnell started building the tenth spacecraft, paraglider gear could be installed at the proper place on the production line.58
On 12 April 1963, Mathews outlined for North American what had to be done at once to put the new program into effect. The company was to stop all work on landing gear for the full-scale test vehicle, since it would now land via parachute, and to forget about trying to convert the half-scale boilerplate into a half-scale test vehicle. Instead, the boilerplate would be used as a tow-test vehicle to work out takeoff techniques needed later for manned flights. North American also had to qualify the new full-scale parachute system, which differed substantially from the emergency system - using three Mercury-type parachutes - that North American had tried hard to qualify, without much success, during the summer and fall of 1962. By the end of April 1963, North American had shifted gears and was working along the lines laid out earlier that month.59
The reoriented paraglider program was formalized in a new contract between North American and NASA on 5 May 1963 that also [134] closed out the earlier contracts. MSC and the contractor agreed on a year-long program (to May 1964) more tightly focused on the basic design of a workable paraglider system than the old had been, with such matters as flight training and production postponed until the design had been proved.60 NASA settled the earlier contracts with North American for $7.8 million and negotiated a $20-million price for the new effort that was intended to save paraglider landing for Gemini.61
Although doing something about paraglider was the most pressing problem Mathews faced when he took over Gemini, Titan II was the greater concern for the program as a whole. So far, Air Force efforts toward clearing up the troubles had been limited to what was needed to make its missile work. Nothing extra was yet being done to see that Titan II met Gemini's needs, although Bernard Schriever had assured Holmes that any Titan II problems that threatened Gemini would be taken care of.62 Pogo seemed to Mathews, as it had to Chamberlin, the most urgent, and Mathews, like Chamberlin, insisted that ±0.25g at the spacecraft was the highest level of vibration that NASA could accept. BSD, however, professed to be content with the g-level of ±0.6g already achieved, well below earlier levels as high as 5g. That was low enough for the missile, and BSD firmly refused to spend any more of its money to lower it further.63
GPO could do little to change BSD's stand, but Schriever, whose command embraced BSD, did have something to say about it. He ordered top officials of both BSD and SSD to his headquarters at Andrews Air Force Base in Maryland on 29 March 1963 to present a status report on Titan II problems related to its role as Gemini launch vehicle. Spokesmen for the major Titan II contractors - Martin, Aerojet, Aerospace, and Space Technology Laboratories - were on hand to discuss their efforts. What Holmes and the other NASA representatives Schriever had invited to the meeting heard was far from reassuring.
Brigadier General John L. McCoy, Director of BSD's Titan System Program Office, led off with an account of the two outstanding problems, longitudinal oscillation and combustion instability. Neither, he stressed, now threatened missile development. Trying to meet Gemini standards by changing any of the missiles still to fly in the development program was too chancy. McCoy's job was to develop a weapon system, which he objected to risking for Gemini.
The contractors argued that the problems were just about solved. Both Aerospace and Martin-Baltimore endorsed the optimistic view of Aerojet General's chief project engineer for Titan II engines, Alvin L. Feldman. Feldman pointed out that Pogo had already responded to increased fuel-tank pressure, and he saw even more promise in a combination of standpipes in the oxidizer lines and mechanical accumulators in the fuel lines. Unstable burning might be handled by modifying [135] the baffles on the injector that fed propellants to the engine or by starting the flow of propellants with some inert fluid.
A closed-door session limited to NASA and Air Force officials followed this open session. Here Holmes vented his frustration at the parade of numbers, statistics, and percentages on Titan II problems he had heard. The crucial point, he insisted, was that no one knew what caused either Pogo or unstable burning; without that knowledge, the booster could not be judged man-rated. Since the Air Force was now a bigger partner than before in Gemini, Holmes thought that Defense funds ought to pay a share of whatever the price might be to fit the launch vehicle to Gemini. But even if NASA had to pay the whole bill, even if Gemini had to face more delays, Holmes wanted these shortcomings corrected. Lieutenant General Howell M. Estes, Schriever's second-in-command, agreed. They decided on a joint development and test program expressly designed to bring Titan II up to Gemini standards, with Air Force Titan II money to get it started and the question of funding the rest to be referred to the Gemini Program Planning Board.64
Just three days later, on 1 April, McCoy was heading a new Titan II/Gemini Coordination Committee,* which, by 5 April, had drawn up a "Joint Titan II/Gemini Development Plan on Missile Oscillation Reduction and Engine Reliability and Improvement." It spelled out the work needed to cut Pogo levels to NASA standards and to reduce the incidence of combustion instability in the second-stage engines. It also outlined an "augmented engine improvement program" to clean up the design of the first- and second-stage engines and to enhance their reliability. McCoy's committee planned to direct the effort, with funds supplied by BSD's Titan System Program Office. The plan to improve and man-rate Titan II had two major restrictions: the weapon-system's flight test program was not to incur undue delays by waiting for Gemini items; and McCoy had the final say on if and when to fly Gemini improvements, with missile program objectives taking precedence.65
The Gemini Program Planning Board concurred in the plan a month later, on 6 May, and recommended that the Department of Defense pay for it, starting at once with current Defense emergency funds. This meant $3 million from fiscal year 1963 money and another $17 million from the next year's budget. The Air Force provided half the $3 million by the end of the month, with a firm promise for the balance.66
In acting on the Titan II plan, the board was moving beyond its charter, which called for it simply to decide what military experiments [136] should be carried on Gemini flights. Its roster of members, however, included Holmes and Schriever, as well as Seamans and McMillan, making it the logical group to coordinate a high-level attack on Titan II's problems. When the board submitted its recommendations to Secretary of Defense McNamara and NASA Administrator Webb on 29 May, no one was surprised that it covered not only experiments but the pursuit "with utmost urgency of" the Titan II improvement plan, using Defense funds and the missile test program.67 McNamara and Webb endorsed the board's findings. McNamara specifically agreed to pay for the program and directed the Secretary of the Air Force both to fund it and to flight-test the improvements in the missile program. In a memorandum to the board members, Webb stressed
the urgency we attach to the development of the Gemini Launch Vehicle. It is of the utmost importance that the cause of the present deficiencies in the Titan II be determined and remedial action accomplished as expeditiously as practicable . . . to eliminate the launch vehicle as a potential source of delay in the Gemini schedule.68The delay was already more than potential, as attested by the major role Titan II problems had played in Gemini's new flight program. But further delays loomed ahead as the Titan II missile test program unexpectedly faltered during the spring of 1963 and threatened to undo the improvement plan before it had fairly begun. The 18th flight test of the Titan II missile was launched on 24 May 1963, It was only the 10th fully successful flight and the last for months to come.69
The next launch, five days later, produced a particularly disappointing failure. Martin, Aerojet, Aerospace, and Space Technology Laboratories had worked hard to confirm the hypothesis that Pogo during first-stage flight was caused by coupling between the missile structure and its propulsion system, the couple making an unstable closed loop. A study of year-old static-firing data led Sheldon Rubin of Aerospace to believe he had found the missing link in the analytic model; the partial vacuum produced by pumping caused hydraulic resonance in the fuel suction line. If valid, this finding would correct the two major shortcomings of prior analyses, which had failed to predict where oscillations ceased during flight and had wrongly predicted that oxidizer standpipes alone would suppress Pogo. Rubin's corrected model showed why Missile N-11 in December 1962 was less stable than other Titan IIs and how adding fuel accumulators as well as oxidizer standpipes would suppress Pogo. The missile launched on 29 May carried Pogo suppression devices for both oxidizer and fuel to test their combined effect. But, leaking fuel in its engine compartment, the missile burst into flame as it lifted off. Its controls damaged by the fire, [137] the missile pitched over and broke up 52 seconds later. In contrast to Missile N-11, the Pogo devices were absolved from any blame for the failures, but the flight ended too soon to provide any Pogo data and the problem remained unsolved.70
This setback was followed by another, on 20 June, in the 20th Titan II flight. This was purely a military test, the missile being launched from a silo at Vandenberg Air Force Base in California. First-stage flight was troublefree, with Pogo levels low enough (±.62g) to meet Air Force standards. But partial clogging of the tiny holes in the oxidizer injector of the second-stage gas generator caused thrust to fall off shortly after staging to about half the required value. The same thing had happened in two earlier tests; had the missile been carrying a spacecraft, its crew would have been forced to abort the mission.71
Back-to-back failures at this stage in the program compelled BSD to suspend Titan II flight testing. Only half the 20 flights so far launched could be called fully successful, and McCoy now faced the task of making good on at least 12 of the 13 flights still left him, to prove that Titan II was ready to join America's strategic deterrent forces. The missile had to come first, and McCoy again ordered a halt to any further attempts to lower Pogo levels as too great a risk to what remained of his test program. Although Major General Ben I. Funk, SSD commander, appealed McCoy's decision to Systems Command Headquarters, the whole question of Gemini-Titan development, and particularly of flight-testing a cure for Pogo, was once more unsettled.
* Members were Richard C. Dineen of SSD, James A. Marsh of Aerospace, and James G. Berry, Titan II project director for Space Technology Laboratories.
55 TWX, R. S. Maynard to MSC, Attn: Bake, "Funding Status, Contract NAS 9-167," MA03449, 2 Feb. 1963; memo, Kline to GPO, Attn: James B. Jackson, Jr., "NAA Wire MA03449 dated February 14 [sic], 1963," APCMG-80-120, 16 Feb. 1963; Change Notice No.6, Contract NAS 9-167, "Gemini Paraglider Program," 12 March 1963; memo, Kline to George F. MacDougall, Jr., "Contract NAS 9-167 for Phase II, Part A of the Gemini Paraglider Program," APCMG-80-305, 1 April 1963; Zavasky, "Minutes of Senior Staff Meeting, March 29, 1963," p. 5; TWX, Maynard to MSC for Kline, MA 10412, 8 April 1963.
56 Charles W. Mathews, activity report, 2531 March 1963; Kline memo, APCMG-80-305, 1 April 1963; TWX, R. L. Stottard to Kline, "Contracts NAS 9-167 and NAS 9-539, Gemini Paraglider Program," 10 April 1963.
57 "Technical Proposal for a Paraglider Landing System," North American, SID 63606-1, 27 May 1963; "Business Management Proposal for a Paraglider Landing System," North American, SID 63-606- 2, 27 May 1963; Storms to MSC, Attn: Stephen D. Armstrong, "Contract NAS 9-1484, Paraglider Landing System Research and Development Program, Transmittal of the Final Fee Settlement Proposal," 65MA3479, 18 March 1965, with enclosure, "A Final Fee Settlement Proposal for Contract NAS 9- 1484," 18 March 1965, p. V26.
58 Purser, "Management Panel Meeting, May 2, 1963," p. 3; Zavasky, "Minutes of Senior Staff Meeting, May 3, 1963," p. 4; Quarterly Status Report No. 5, p. 51; TWX, John Y. Brown to MSC, Attn: Mathews, "Mission Definitions for Program Planning," 306-16-2199, 16 April 1963; letter, Mathews to Walter C. Burke, Attn: Brown, GPO-00887, 24 May 1963, with enclosure, launch schedule and mission definition.
59 TWX, Mathews to Jeffs, Attn: Tischler, and to Burke, Attn: Robert N. Lindley, GPO-50774, 12 April 1963; Amendment No. 8, Contract NAS 9-167, "Paraglider Development Program Phase II, Part A," 12 April 1963; memo, Mathews to Kline, "Contracts NAS 9-167 and NAS 9-539, Paraglider Landing System," GPO-00767, 24 April 1963; TWX, Jeffs to MSC for Mathews, "Re-Directed Gemini Paraglider Program," MA12552, 30 April 1963.
60 Memo, Mathews to Kline, "Initiation of a Development Program for a Paraglider Landing System," GPO-00807, 29 April 1963; Mathews, activity report, 5-11 May 1963, p. 1; letter, Kline to North American, 3 May 1963, with enclosure, letter contract NAS 9-1484 for Paraglider Landing System, accepted by Waite, 5 May 1963; Mathews, activity report, 28 April - 4 May 1963, p. 2; letter, Gilruth to Dir., Flight Research Center, "Participation of Flight Research Center in Paraglider Flight Test Program," GPO-00851, 6 May 1963; memo, Bailey to Contract NAS 9-167 File, no subject, APCM-71- 1507, 9 May 1963; memo, Bailey to Contract NAS 9-539 File, no subject, APCM-71-1508, 9 May 1963; Consolidated Activity Report, 28 April - 18 May 1963, p. 33.
61 Kline, "Summary of Negotiations," 24 July 1963; NASA Negotiated Contract, NAS 9-1484, "Paraglider Landing System Research and Development Program," 12 July 1963, signed by Waite (26 July) and Kline (5 Aug.); Supplemental Agreement No. 5, NAS 9-167, 12 July 1963; Supplemental Agreement No. 6, NASA 9-539, 12 July 1963.
62 Holmes memo, 25 March 1963.
63 Zavasky, "Minutes of Senior Staff Meeting, March 22, 1963," p. 5; TWX, Mathews to Dineen, GPO-50770, 28 March 1963.
64 Zavasky, "Minutes of Senior Staff Meeting, March 29, 1963," p. 4; memo, Edmund E. Novotny for record, "Briefing on TITAN II/GEMINI Problems, 29 March, 1963," 2 April 1963; memo, George M. Low to Assoc. Adm., "Titan II Fix Program," 5 July 1963; "Joint Titan II/Gemini Development Plan," p. 5.
65 Low memo, 5 July 1963; "Joint Titan II/Gemini Development Plan."
66 "Minutes of the Fifth Meeting, Gemini Program Planning Board, Monday, May 6, 1963"; memo, Boone to Webb and Hugh L. Dryden, "Funds for Martin Company to study Titan II difficulties," 9 May 1963; memo, Boone to Webb, subject as above, 20 May 1963; letter, Novotny to McKee, "TITAN II/ GEMINI Get Well Program," 28 May 1963; memo, McKee to Dep. Dir. (Programs), OMSF, "Titan II Fixes," 28 May 1963; memo, Boone to Seamans, "Status of funds for the Titan II fixes and general improvement program," 20 Sept. 1963.
67 Memo, Seamans and McMillan to Sec. of Defense and Adm., NASA, "Recommendations by the Gemini Program Planning Board," 29 May 1963.
68 Memo, McNamara to Co-Chairmen of the Gemini Program Planning Board (GPPB), "Recommendation of the GEMINI Program Planning Board," 20 June 1963; memo, McNamara to Sec. of the Air Force, "Recommendation of the GEMINI Program Planning Board," 20 June 1963; memo, Webb to CoChairmen of the GPPB, "Recommendations by the Gemini Program Planning Board," 24 June 1963.
69 John J. Gabrik, "Titan II Post Flight Briefing Report," n.d., for Missile N-17, flight on 24 May 1963; Quarterly Status Report No. 5, pp. 41-42; Mathews, activity report, 20-25 May 1961; memo, Sheldon Rubin to Dineen, "Results of Analysis of N-25 Configuration on Aerospace Analog Model of POGO," Aerospace 63-1944-51, 15 Oct. 1963; memo, David B. Pendley to Chief, Flight Operations Div., "Titan II Coordination Meeting of June 14, 1963," 17 June 1963; "Abstract of Meeting on Titan II, June 14, 1963," 19 June 1963.
70 "Titan II Post Flight Briefing Report," n.d., Martin, for Missile N-20, flight on 29 May 1963; Pendley memo, 17 June 1963; "Titan II Meeting, June 14, 1963"; Mathews, activity report,2-8 June 1963, p. 2; Prause and Goldman, "POGO Study," p. 4. 71 "GLV Analysis of Titan II Flights," Martin, n.d., for Missile N-22, 20 June 1963; Quarterly Status Report No. 5, pp. 41-42.