The statement of work for Titan II that SSD had received early in January called for more than the limited modifications first proposed. It required a malfunction detection system and other unspecified changes to improve the missile. Making sure that Titan II could safely launch manned spacecraft - referred to as manrating - was crucial, and it was going to cost money. A revised statement of work in mid-May 1962 spoke of "an adaptation of the Titan II ICBM," rather than "a development of the present Titan II ICBM," and spelled out the changes required in greater detail. They included not only a fully redundant malfunction detection system but also a backup flight control system; an electrical system with backup circuits for guidance, engine shutdown, and staging; inertial instead of radio guidance; and a new launch tracking system.3
The target vehicle likewise soon seemed to demand more than had first been expected. Even though Agena work was moving at a slower pace, by May the $88 million programmed for Atlas-Agena development in the December 1961 plan had climbed above $106 million.4
The project development plan had the Gemini spacecraft costing $240.5 million. This figure, like those for launch and target vehicles, could not have been more than an educated guess, with a natural bias toward guessing on the low side to make the program more palatable. But McDonnell's first formal cost proposal for the Gemini spacecraft still came as something of a shock. The first step in negotiations between the project office and McDonnell to convert the letter contract of December 1961 into a definitive contract was a series of technical meetings in Houston between 19 April and 24 May 1962, to make sure that both sides agreed on plans and specifications.5 McDonnell's "Gemini Spacecraft Cost and Delivery Proposal," prepared for these meetings, raised the spacecraft ante to $391.6 million.6
This new and higher estimate was based in part on McDonnell's more careful study of the cost of what the contract called for, in part on its enlarged view of what the program ought to include. The letter contract, for example, had mentioned the need for flight simulators and trainers as well as test spacecraft but included no specifics.  A new feature of engineering development for Gemini was to be the use of a number of test articles - spacecraft built for early static and dynamic testing - for want of which Mercury had sometimes been delayed. GPO admitted that building them might slow spacecraft construction at first but believed that the data they provided would more than make up for the temporary setback.7 McDonnell proposed four boilerplate spacecraft (metal models designed to be used chiefly in escape and recovery system testing) and four static articles (non-flying spacecraft to be used in structural tests). McDonnell also proposed to add to Gemini a test program that it had worked out in Mercury. Known as "Project Orbit," this entailed building an extra spacecraft and target docking adapter for an extended series of laboratory-simulated orbital missions "to investigate potential problems and to evaluate engineering changes generated during the life of the program."8
A major part of crew training for Gemini depended on simulating in great detail every aspect of a mission, to expose the astronauts before they left the ground to anything they might meet during a flight. The basic device was a flight trainer, a precise duplicate of the real spacecraft, in which crews could fly a complete simulated mission from launch through touchdown, seeing through its windows what they would see in flight, hearing the noises - even feeling the vibrations - they could expect. There were to be two flight trainers, one in Houston and the other at Cape Canaveral, each hooked up to mission control and remote displays to form a complete mission simulator.
Three aspects of a mission were outside the scope of the flight trainers. One involved the forces imposed upon the astronauts by high acceleration during launch and by rapid deceleration during reentry. These stresses could be matched on a man-carrying centrifuge. The project office planned to use the one at the Naval Air Development Center in Johnsville, Pennsylvania, its gondola fitted out with a mockup of the inside of the spacecraft. Maneuvering in orbit to rendezvous was the second aspect. This was to be simulated by a translation and docking trainer, in which the crews would practice techniques of rendezvous and docking.9 The third, extended weightlessness, was then beyond human ingenuity to imitate.
Training equipment and test articles together, increased in detail and enlarged in scope, came to just under $39 million in McDonnell's cost proposal. McDonnell also needed money to cover its roles in mission planning and launch operations support and for spare parts and checkout gear, to name only some of the more costly items. And all this aside from the expense of developing and building the spacecraft ($242.7 million), which alone exceeded the December budget ($240.5 million).10 Even at that, McDonnell's estimate was still little more than guesswork. Few of the company's subcontractors had yet provided any hard financial data. The chiefs of procurement and financial management  at MSC jointly deplored both the size of the McDonnell estimate and the lack of data on which it was based, a viewpoint that echoed Paul Purser's marginal note on SSD's interim financial plan for boosters in April 1962: "This is still up in the air. Attempts are being made to bring down these costs." 11
On 12 May 1962, in a review of Project Gemini for NASA Administrator James Webb, the Office of Manned Space Flight revealed for the first time the pattern of rising costs that was beginning to mark the program. Since the project development plan was issued, little more than five months earlier, Gemini's expected cost had climbed from $529.5 million to $744.3 million.12 Given the shaky data on which the new total depended, it could not be the last word. The program kept growing and technical problems began to appear, not all of them in areas where they had been expected.
2 "Project Development Plan for Rendezvous Development Utilizing the Mark II Two Man Spacecraft," MSC, 8 Dec.1961, p.21; letter, Ralph C. Hoewing to MSC, Attn: George F. MacDougall, Jr., "Gemini Launch Vehicle Financial Plan," 4 April 1962, with enclosures.
3 NASA-Defense Purchase Request T-2356-G, signed by Leslie E. Berg, 15 May 1962, with enclosure, "Statement of Work to Be Accomplished under Department of Defense Purchase Request No. T2356G," 14 May 1962.
4 "Project Development Plan," p. 21; memo, D. Brainerd Holmes to Adm., "Project Gemini Cost Estimates," 29 April 1963, with enclosure, "Status of Project Gemini Cost Estimates."
5 Memo, Dave W. Lang to Charles F. Bingman, "Weekly Activity Report," 20 April 1962, with enclosure, "Weekly Activity Report, Procurement and Contracts Division, April 16-20, 1962"; "Abstract[s] of Technical Negotiation Meeting[s] on": "Simulators and Trainers, April 19, 1962," 24 April 1962; "Support Plan - MAC Report No.8580-4, dated February 2, 1962, April 23 and 24, 1962," 2 May 1962; "Associate Contractor Coordination, Engineering Inspections and Incorporation of Government Furnished Equipment, April 24, 1962," 16 May 1962; "Gemini Facility Plans, MAC Report 8580-2, dated 15 March 1962, April 24, 1962," 4 May 1962; "Documentation Plan, MAC Report No. 8580-8, dated 29 January 1962, April 25, 1962," 4 May 1962; "Post Landing and Survival System, April 26, 1962," 27 April 1962; "Programmer/Timer (Time Reference), April 26, 1962," 1 May 1962; "Environmental Control Subsystem, April 26, 1962," 27 April 1962; "Propulsion Systems, April 26, 1962," 1 May 1962; "Environmental Criteria, April 26, 1962," 1 May 1962; "Communication System Specification, April 27, 1962," 1 May 1962; "Crew Station System Specification, April 27, 1962," 4 May 1962; "Pyrotechnics System Specification, April 27, 1962," 4 May 1962; "Guidance and Control System Specification, April 27, 1962," 9 May 1962; "Electrical System Specification, April 27, 1962," 3 May 1962; "Structural Design Criteria, April 28, 1962," 1 May 1962; "Landing System, April 28, 1962," 11 May 1962; "Gemini Spacecraft Performance Specification, revised May 1, 1962," 5 May 1962; "Program Progress Report, May 2, 1962," 8 May 1962; "Test Program, May 7, 1962," 21 May 1962; "Reliability Plan, MAC Report No. 8580-3, dated February 5, 1962, May 8, 1962," 11 May 1962; "Quality Assurance Plan, MAC Report No. 8580-7, dated January 22, 1962. May 9, 1962," 11 May 1962; "Validation Testing, May 18, 1962," 23 May 1962; André J. Meyer, Jr., interview, Houston, 9 Jan. 1967.
6 "Gemini Spacecraft Cost and Delivery Proposal," MAC Report No. 8791, 18 April 1962, p. 18.
7 "Project Gemini Schedule Analysis," GPO, 14 March 1962, p. 2.
8 "Gemini Spacecraft Cost and Delivery Proposal," pp. 5-6; cf. Loyd S. Swenson, Jr., James M. Grimwood, and Charles C. Alexander, This New Ocean: A History of Project Mercury, NASA SP-4201 (Washington, 1966), pp. 269-70.
9 "Abstract of Meeting on Simulators and Trainers, March 28, 1962," 3 April 1962; memo, Harold I. Johnson for all concerned, "Preliminary description of simulators and training equipment expected to be used in Project Gemini," 5 March 1962; Project Gemini Quarterly Status Report No. 1, for period ending 31 May 1962, pp. 38-39.
10 "Gemini Spacecraft Cost and Delivery Proposal," pp. 17-19.
11 Memo, Lang and Rex L. Ray to Wesley L. Hjornevik, "Appraisal of validity of McDonnell Estimates of Cost of Gemini Contract Work," 17 April 1962, with enclosures; Hoewing letter, 4 April 1962, with Paul E. Pursers annotation, undated.
12 Holmes memo, 29 April 1963.