Trident II D-5 Fleet Ballistic Missile

Background

The Deputy SECDEF approved a Decision Coordinating Paper (DCP) No. 67 on 14 September 1971 for the ULMS Program, a long-term modernization plan which called for a new, larger submarine and a new, longer-range missile while preserving a nearer-term option to develop an extended-range POSEIDON missile. And in December 1971, the Deputy SECDEF PBD authorized an accelerated ULMS schedule with a projected deployment of the new SSBN and missiles in 1978. In May 1972, the term "TRIDENT" replaced "ULMS," the name "TRIDENT II" was used to designate the ultimate longer-range missile, and the Navy Program Objectives Memorandum (POM) submission outlined funding for the TRIDENT II (D5) program based on a 1984 IOC. Later on 3 August, the SECDEF in a Program Decision Memorandum (PDM) advanced the D5 IOC 2 years to FY 1982. So it beganoscillating D5 IOC dates and associated impacts to the TRIDENT I (C4) development program schedule.

Also on 18 October 1973, a TRIDENT I DSARC (Defense Systems Acquisition Review Council) II and an overall TRIDENT program review was conducted. On 14 March 1974, the Deputy SECDEF issued two requirements. The first requirement was parallel (to C4 development) advanced development effort for major accuracy improvement in the C4 and follow-on missiles (beginning of the IAP). The second requirement was for follow-on alternatives to the C4 missile, or a new D5 missile, or a variant of C4 with larger first stage motor.

The SSPO responded to this second requirement in May 1974 with a brief report grouping candidate missile alternatives into three basic categories: (1) C4 alternatives, 74 in. missiles with varying degrees of C4 commonality; (2) various "stepped" D5 missile alternatives with an 82 in. first stage and 74 in. upper stages that were similar to C4; and (3) D5 alternatives which were all-new, 82 in. missiles.

An abnormal rate of inflation in 1974, plus future increases projected for 1975 - 76, resulted in a SECDEF directed IOC slip of the TRIDENT II to CY 1983. This was followed by a SECDEF decision in January 1975 to a further slip to FY 1985 due to budgetary problems.

On 10 February 1975, the SECDEF issued a study directive for examining feasible degrees of the Air Force's Missile X (MX)-TRIDENT II commonality, potential performance degradations, and resultant cost advantages associated with the various degrees of commonality. It was also during this time frame that the TRIDENT II Characteristics Study was underway. The Navy's perception of the specific military requirement for TRIDENT II were in a state of flux. Hard-target capability appeared to be in the SECDEF's mind but no firm nuclear weapons employment policy appeared. In fact, none was likely until MX commonality and possible improved accuracy alternatives were resolved. In line with this, the SECDEF, on 23 July 1975, deferred TRIDENT II operational availability date (OAD) to 1987.

On 3 May 1976, the Deputy SECDEF wrote to the SECNAV, outlining the desirability of SWS having both survivability and a wide range of capability. The TRIDENT submarine, having invulnerability as well as the potential for increased throwweight, "encourages consideration of options to expand our SLBM capability against the full spectrum of the target system." The Navy was therefore requested to develop an overall TRIDENT II missile development plan for increasing the "utility" of the FBM system for IOC in the 1980s.

In the meantime, in 1976 Congress, for the second consecutive year, denied the Navy's request for research, development, test, and evaluation (RDT&E) funding to initiate TRIDENT II conceptual development.

On 16 August 1976, when the SECNAV responded to the Deputy SECDEF above-mentioned guidance outlining TRIDENT II conceptual goals for an all new D5 hard-target systemhe noted that only minimal in-house effort could be undertaken in FY 1977. But assuming that TRIDENT II funding would be available in FY 1978, it still appeared feasible to plan for a 1987 IOC. Meeting such a schedule, however, would definitely be contingent upon DoD waiver of normal acquisition procedures.

Subequently, trade studies were conducted to define the extent to which the more-expensive elements of the new Trident-II missile would be common with the new Air Force MX ICBM, while unique subsystems could be added to utilize the larger missile sizes usable in the MX weapon system. A TRIDENT II baseline was defined as a point of departure for the study. Although uncorroborated by detailed study, the probable target missile that could be accommodated in the TRIDENT submarine (83 in. diameter and 44 ft length) was established in order to provide maximum performance in the MX application. This baseline TRIDENT II, with a modification to the guidance system, additional electronics hardening, and the addition of an external protective coating for dust and debris protection, was determined to be the common missile. It satisfied the Navy TRIDENT II requirements established for this study but did not satisfy Air Force payload requirements.

The mostly-common missile was a variant to this common missile where, for Air Force application, a unique propulsion stage was used between the common first stage and second stage to configure a longer three-stage missile with increased range/payload performance. It was estimated that 6 to 6 years would be required to develop these missiles after an initial year of detailed program, requirements, and interface definition. The management plan recommended that a single service, either the Air Force or the Navy, should be responsible for development and acquisition of the common or mostly-common missiles. Each service would continue to be responsible for development and acquisition of its unique weapon system elements.

In September 1978, the studies were extended to another variation of commonality wherein two boost propulsion motors would be common for use as TRIDENT II first stage and SS, and as MX first stage and TS. Prospects for the TRIDENT II program were not improved when Congress appropriated only $5 million of the requested $15 million requested for FY 1979. The SECDEF showed a 1990 IOC of the program was funded at a decremented level.

By December 1978, it was the consensus of the Navy, Air Force, and USD&RE that the relatively-small cost advantage (estimated $300 million Navy savings in 1979 dollars) would not offset the risks and disadvantages of a common missile. SSPO internal planning guidance was for a stand-alone TRIDENT II, IOC FY 1990. Thus, the Navy felt free to proceed with TRIDENT II, whatever it might be, and that was the problem.

The Congress felt there was no clearly-delineated requirement for TRIDENT II, and Congressional conferences on appropriations provided only minimal budgets. In addition, the DOD and the Navy positions on types of effort and level of funding fluctuated. In fact, the Navy was instructed in November 1979 to pursue a program of incremental submarine-launched ballistic missile modernization, citing the Presidential decision for full MX development and the difficulty of funding more than one program at a time.

In March 1980, the SECDEF, in his budget submittal to Congress for FY 1981, proposed a significantly-increased level of funding for submarine-launched ballistic missile modernization. The principle emphasis was accuracy improvement applicable to an upgraded C4, a long C4, or an all-new D5 missile which would fill the TRIDENT SSBN launch tube envelope and be capable of increased range, payload, as well as accuracy. A review was to be conducted at the end of FY 1983 to select a modernization option for an IOC not later than CY 1989. As to the issue of affordability, the proposed DoD budget requested $36 million for FY 1981 and reprogramming from other sources of $61 million which would provide $97 million for the first year of ADP.

The House Armed Services Committee (HASC) recommended no funding, but the Senate Armed Services Committee (SASC) recommended a full $97 million. However, the SASC asked for a plan to be provided which incorporates "the fullest possible competition... (and) should consider competing among contractors for each major component, including the integrated missile." If the plan were to reveal that competition of such major components was not in the best interests of the U. S., then a justification should be supplied. Finally, $65 million was appropriated for submarine-launched ballistic missile modernization.

On 6 March 1981, as requested by the SASC, the DoD forwarded the Navy's submarine-launched ballistic missile Modernization Acquisition Plan to the Committees on Armed Services.The letter of transmittal again endorsed an acquisition approach consonant with the evolutionary nature of the submarine-launched ballistic missile program and DoD policy on the issue since 1977. Essential to the plan would be retention of the proven SSPO management structure and the existing Navy/contractor subsystem management teams, with maximum competition at the subcontract level. Since accuracy improvement was a major and challenging objective of the program, use of the existing contractor team was considered the most-efficient approach. The Plan noted that competition at the prime contractor level would result in a duplication of efforts and facilities, a significant increase in program costs, and a delay of the proposed system IOC by approximately 2 years.

On 2 October 1981, President Reagan made an address which called for modernization of the strategic forces. The Defense Department immediately directed the Navy to fund development of the D5 missile with a December 1989 IOC. The planned TRIDENT I missile inventory- would-be reduced from 969 to 630s and all RDT&E effort would be directed toward "a new development, advanced technology, high accuracy D5 system."

Initially, the Navy planned to introduce D5 by backfitting it into the 12th TRIDENT submarine constructed for the C4 system. However, a restructured plan announced on 1 June 1982 introduced the new system with the ninth new construction hull, obviating the need for backfitting four boats, increasing the rate of deployment, and resulting in a cost avoidance of $680 million (FY 1983 dollars).

And in keeping with the objective of effectiveness against the entire target spectrum, Deputy SECDEF Frank Carlucci advised the SECNAV in December 1982 to include funding for a new RV/warhead combination for TRIDENT II. The new reentry vehicle designated Mk 5, was to have a higher yield than the Mk 4, thus increasing the weapon system's effectiveness against hard targets.

Finally, the Deputy SECDEF on 28 October 1983 authorized the Navy to proceed to Full Scale Engipeering Development (FSED) of the TRIDENT II (D5) SWS and initiate production to meet a December 1989 IOC. Thus, the third and final phase of the Navy's ULMS program long-term modernization plan was underway.

The D5 Development Flight Test Program originally consisted of 20 D5X missile flat pad flights and 10 PEM flights from a TRIDENT SSBN. Flight testing began in January 1987 and in 1988. The program was reduced to 19 D5Xs and 9 PEMs.

The flight test program of the missile and the guidance subsystems of the weapon system began in January 1987, and the overall performance results from the tests indicated that the missile was achieving its objectives for this phase of the program. Of the 15 tests conducted as of September 30, 1988, 11 were successful, 1 was partially successful, 2 were failures, and one was a "no-test" [the 15th flight test was destroyed by command destruct early in its flight while the missile was performing normally at the time the decision was made to destruct: therefore, the flight was a "no-test"]. Although the majority of the tests were successful, each of the failures involved different problems and occurred at different stages of the missile flight.

A problem encountered during the seventh flight requires a redesign of the Post Boost Control System. During the deployment phase of the seventh flight, one of the valves in the system, which controls the flow of hot gases through the system, remained closed and limited the system's steering capability. Engineering evaluations indicate there was overheating or contamination in the valve, causing it to stay closed. The redesign was incorporated during the 1989 testing program.

During the ninth flight test, the missile lost control and went off course about 14 seconds into third stage flight and self-destructed. Engineering verification of the failure indicated that a short in one of the power supplies, which control the flight control computer, prevented the computer from providing the proper steering commands for the missile's third stage. The problem was solved through minor changes in the flight control computer. Also, there has been no reoccurrence of the problem in subsequent flight tests.

During the 13th flight, the missile encountered a problem with the thrust vector control subsystem on its first stage, causing it to lose control and go off course about 55 seconds into flight.) The missile was destroyed by the range safety officer for safety reasons.

During the 15th flight, the missile was destroyed by command destruct early in its flight. The missile wars performing normally at the time the decision was made to destruct, thus resulting in a no test. A combination of events prompted the destruct action, including the specific trajectory selected to be flown, the prelaunch weather conditions, and the missile dynamics along the flight path, which resulted in the missile looking to the range safety officer as though itwould cross the boundaries of the safety corridor.