HGM-25A Titan I
|This article needs additional citations for verification. (February 2011)|
Launch of a Titan I SM/567.8-90 ICBM from Cape Canaveral
|Country of origin||United States|
|Cost per launch||US$ 1.5 million|
|Launch sites||Cape Canaveral LC-15, LC-16, LC-19 & LC-20
Vandenberg AFB OSTF SLTF LC-395
|First flight||6 February 1959|
|Last flight||5 March 1965|
|Thrust||1,900 kN (430,000 lbf)|
|Specific impulse||290 seconds|
|Burn time||140 seconds|
|Thrust||356 kN (80,000 lbf)|
|Specific impulse||308 sec|
|Burn time||155 seconds|
The Martin Marietta SM-68A/HGM-25A Titan I was the United States' first multistage rocket Intercontinental ballistic missile (ICBM), in use from 1959 until 1965. Incorporating the latest design technology when designed and manufactured, the Titan I provided an additional nuclear deterrent to complement the U.S. Air Force's SM-65 Atlas missile. It was the first in a series of Titan rockets, but was unique among them in that it used liquid oxygen and RP-1 as propellants, while the later Titan ICBM versions all used storeable fuels instead. Though the SM-68A was operational for only three years, it was an important step in building the Air Force's strategic nuclear forces.
The program began in January 1955 and took shape in parallel with the Atlas (SM-65/HGM-16) intercontinental ballistic missile (ICBM). The Air Force's goal in launching the Titan program was threefold: one, to serve as a backup should Atlas fail; two, to develop a large, two-stage missile with potentially superior performance; and third to introduce competition which the head of Ballistic Missile Division, Brigadier General Bernard Schriever, thought might spur the Atlas contractor to work harder Martin was selected as the contractor for two reasons. First it proposed a superior organization. Second was that Martin proposed a method of dealing with the problem of igniting a liquid fueled engine at high altitude.
The Titan I was initially designated B-68 in the numbering sequence of bombers. It was later designate SM-68; then redesignated HGM-25A.
Produced by the Glenn L. Martin Company (which became "The Martin Company" in 1957), Titan I was a two-stage, liquid-fueled missile with an effective range of 5,500 nautical miles (10,200 km). The first stage delivered 300,000 pounds (1,330 kN) of thrust, the second stage 80,000 pounds (356 kN). The fact that Titan I, like Atlas, burned RP-1 and LOX meant that the oxidizer had to be loaded onto the missile just before launch from an underground storage tank, and the missile raised above ground on the enormous elevator system, exposing the missile for some time before launch. The complexity of the system combined with its relatively slow reaction time – fifteen minutes to load, raise and launch the first missile, made it a less effective weapon system. Following the launch of the first missile the other two could be fired at 7-1/2 minute intervals.
Titan I utilized radio-inertial command guidance. The inertial guidance system originally intended for the missile was instead eventually deployed in the Atlas E and F missiles. Less than a year later the Air Force considered deploying the Titan I with an all-inertial guidance system but that change never occurred. (The Atlas series was intended to be the first generation of American ICBMs and Titan II (as opposed to Titan I) was to be the second generation deployed). The Titan 1 was controlled by an autopilot which was informed of the missile's attitude by a rate gyro assembly consisting of 3 gyroscopes. During the first minute or two of the flight a pitch programmer put the missile on the correct path. From that point the AN/GRW-5 guidance radar tracked a transmitter on the missile. The guidance radar fed missile position data to the AN/GSK-1 (Univac Athena) missile guidance computer in the Launch Control Center. The guidance computer used the tracking data to generate instructions which were encoded and transmitted to the missile by the guidance radar. Guidance input/output between the guidance radar and guidance computer occurred 10 times a second. Guidance commands continued for the sage 1 burn, the stage 2 burn and the vernier burn ensuring the missile was on the correct trajectory and terminating the vernier burn at the desired velocity. The last thing the guidance system did was to determine if the missile was on the tight trajectory and pre-arm the warhead which then separated from the second stage. In case of the failure of the guidance system at one site, the guidance system at another site could be used to guide the missiles of the site with the failure.
Titan I also was the first true multi-stage (two or more stages) design. Whereas in Atlas, all rocket engines were ignited at launch (including two small thrust vernier engines) due to concerns about igniting rocket engines at high altitude and maintaining combustion stability.  Martin, in part, was selected as the contractor because it had "recognized the 'magnitude of the altitude of the altitude start problem' for the second stage and had a good suggestion for solving it." Titan I's second-stage engines were reliable enough to be ignited at altitude, after separation from the first stage booster. The first stage, besides including heavy fuel tanks and engines, also had launch interface equipment and the launch pad thrust ring with it. When the first stage had finished consuming its propellant, it dropped away, thereby decreasing the mass of the vehicle. Titan I’s ability to jettison this mass prior to the ignition of the second stage meant that Titan I had a much greater total range (and a greater range per pound of second-stage fuel) than Atlas, even if the total fuel load of Atlas had been greater.
The warhead of the Titan I was an AVCO Mk 4 re-entry vehicle containing a W38 thermonuclear bomb with a yield of 3.75 megatons which was fuzed for either air burst or contact burst. The Mk 4 RV also deployed penetration aids in the form of mylar balloons which replicated the radar signature of the Mk 4 RV.
Research and development
The Titan I was tested in a comprehensive test program prior to deployment. From the first successful launch on 5 February 1959 with Titan-1 A3 through to 29 January 1962 Titan-1 M7. There were seven variants of the Titan-1 Research and Development missile: six A-types (four launched) seven B-types (two launched), six C-types (five launched), ten G-types (seven launched), 22 J-types (22 launched), four V-types (four launched), seven M-types (seven launched). 62 produced (49 launched and two exploded). They were tested and launched at Cape Canaveral Air Force Station from Launch Complexes LC15, LC16, LC19 and LC20.
The first four tests of the Titan I (the Lot A missiles) were carried out on February 6, February 25, April 3, and May 4, 1959, all with dummy second stages. The success of these initial flights left launch crews unprepared for the coming events. On August 14, the first attempt to fly a Lot B (all-up version with a live second stage) ended in disaster when the missile was released from LC-19 before it had built up sufficient thrust. The pad umbilical sent a shutdown signal to the engines and the Titan fell back onto the pad and exploded.
In December, the second attempt to launch a complete Titan ended in practically identical fashion when vibration tripped the range safety destruct package on the first stage of Missile C-3 one second after liftoff, leading to another pad explosion. On February 2, 1960, Missile B-7 marked the first successful flight of a Titan with a live upper stage. On February 5, Missile C-4 failed at T+52 seconds when the guidance compartment collapsed from aerodynamic pressure, causing the RVX-3 reentry vehicle to separate. The missile pitched down and was blown up by Range Safety. After first stage destruction, the second stage separated and began engine ignition, sensing that normal staging had taken place. With no attitude control, it began tumbling end-over-end and quickly lost thrust. The stage plummeted into the Atlantic Ocean some 30-40 miles downrange. After the successful flight of Missile G-4 on February 24, Missile C-1's second stage failed to ignite on March 8 due to a stuck valve preventing the gas generator from starting. A run of successful launches followed during the spring, but the first attempt at flying a Lot J missile on July 1 went awry when a broken hydraulic line caused total loss of control within moments of liftoff. The Titan began flying on a near horizontal plane before Range Safety issued the destruct command at T+11 seconds. The next launch at the end of the month (Missile J-4) suffered premature first stage shutdown and landed far short of its planned impact point. Cause of the failure was a LOX valve closing prematurely, which resulted in the rupture of a propellant duct and thrust termination. Missile J-6 on October 24 set a record by flying 6100 miles.
The string of failures during 1959-60 led to complaints from the Air Force that Martin-Marietta weren't taking the Titan project seriously (since it was just a backup to the primary Atlas ICBM program) and displayed an indifferent, careless attitude that resulted in easily avoidable failure modes such as Missile C-3's range safety destruct charges being placed in a vibration-prone area.
In December, Missile V-2 was undergoing a flight readiness test in a silo at Vandenberg Air Force Base. The plan was to load the missile with propellant, raise it up to firing position, and then lower it back into the silo. Unfortunately, the silo elevator collapsed, causing the Titan to fall back down and explode. The blast was so violent that it ejected a service tower from inside the silo and launched it some distance into the air before coming back down.
Although most of the Titan I's teething problems were worked out by 1961, the missile was already eclipsed not only by the Atlas, but by its own designated successor, the Titan II, a bigger, more powerful ICBM with storable hypergolic propellants. The launch pads at Cape Canaveral were quickly converted for the new vehicle and as Vandenberg lacked actual pads (only silos), the Titan I quickly found itself homeless. After a brief period as an operational ICBM, it was retired from service in 1965 when Defense Secretary Robert McNamara made the decision to phase out all first generation cryogenically-fueled missiles in favor of newer hypergolic and solid-fueled models. While decommissioned Atlas (and later Titan II) missiles were recycled and utilized for space launches, the Titan I inventory was simply scrapped.
Titan-1 Strategic Missile (SM) production began during the final stages of the Research and Development program[when?]. In total, 101 Titan-1 SMs were produced to be tested from underground silos at Vandenberg Air Force Base and then stationed in silos in six squadrons of nine missiles each across America. Fifty-four missiles in silos in total, with one missile as a spare on standby at each squadron, bringing to 60 in service at any one time.
The Titan I was first American ICBM based in underground silos, and it gave USAF managers, contractors and missile crews valuable experience building and working in vast bunkers containing everything the missiles and crews needed for operation and survival. The complexes were composed of a control center, powerhouse, and two antenna silos for the ATHENA guidance radars.
These early silos, however, had certain drawbacks. First, the missiles took about 15 minutes to fuel, and then had to be lifted to the surface on huge elevators for launching, which slowed their reaction time. Rapid launching was crucial to avoid possible destruction by incoming missiles, even though Titan shelters were designed to withstand nuclear blasts. Second, the missiles' placement close together in groups of three—necessary because they shared a single ground-based radio guidance system—made them vulnerable to nuclear attack. All-inertial guidance, which does not depend on ground computers, was not yet perfected.
The distance between the antenna silos and the most distant missile silo was between 1,000 and 1,300 feet (400 m). These were by far the most complex, extensive and expensive missile launch facilities ever deployed by the USAF. Launching a missile required fueling it in its silo, and then raising the launcher and missile out of the silo on a massive elevator. Before each launch the guidance radar had to be calibrated by acquiring a special target at a precisely known range and bearing. When the missile was launched, the guidance radar tracked the missile and supplied precise velocity range and azimuth data to the missile's guidance system. Because of this the complex could only launch and track one missile at a time.
Although Titan I's two stages gave it true intercontinental range and foreshadowed future multistage rockets, its propellants were dangerous and hard to handle. Super-chilled liquid oxygen oxidizer had to be pumped aboard the missile just before launch, and complex equipment was required to store and move this liquid. Kerosene fuel also was pumped aboard just before launch.
In its brief career, six squadrons were equipped with the Titan I. Each squadron was deployed in a 3x3 configuration, which meant a total of nine missiles were divided into three launch sites in Colorado, Idaho, California, Washington state and South Dakota. Each missile site had three Titan I ICBM missiles ready to launch at any given time. See squadron article for location of launch sites.
- 568th Strategic Missile Squadron April 1961 – March 1965
- 569th Strategic Missile Squadron June 1961 – March 1965
- 724th Strategic Missile Squadron April 1961 – June 1965
- 725th Strategic Missile Squadron April 1961 – June 1965
- 850th Strategic Missile Squadron June 1960 – March 1965
- 851st Strategic Missile Squadron February 1961 – March 1965
- Liftoff thrust: 1,296 kN Total mass: 105,142 kg
- Core diameter: 3.1 m. Total length: 31.0 m
- Development cost: $1,643,300,000 in 1960 dollars.
- Flyaway cost: $1,500,000 each, in 1962 dollars.
- Total production missiles built: 163 Titan 1s; 62 R&D Missiles – 49 launched & 101 Strategic Missiles (SMs) – 17 launched.
- Total deployed Strategic Missiles: 54.
- Titan Base Cost: $170,000,000 (US$ 1.36 in 2016)
- Gross mass: 76,203 kg
- Empty mass: 4,000 kg
- Thrust (vac): 1,467 kN
- Isp (vac): 290 s (2.84 kN·s/kg)
- Isp (sea level): 256 s (2.51 kN·s/kg)
- Burn time: 138 s
- Diameter: 3.1 m
- Span: 3.1 m
- Length: 16.0 m
- Propellants: liquid oxygen (LOX)/kerosene
- Number of engines: Two – Aerojet LR-87-3
- Gross mass: 28,939 kg
- Empty mass: 1,725 kg
- Thrust (vac):356 kN
- Isp (vac): 308 s (3.02 kN·s/kg)
- Isp (sea level): 210 s (2.06 kN·s/kg)
- Burn time: 225 s
- Diameter: 2.3 m
- Span: 2.3 m
- Length: 9.8 m
- Propellants: liquid oxygen (LOX)/kerosene
- Number of engines: One – Aerojet LR-91-3
The number of Titan I missiles in service, by year:
- 1961 – 1
- 1962 – 62
- 1963 – 63
- 1964 – 56
When the storable-fueled Titan II and the solid-fueled Minuteman I were deployed in 1963, the Titan I and Atlas missiles became obsolete. They were retired from service as ICBMs in early 1965. The count as of 5 March 1965 (the final launch from Vandenberg Air Force Base (VAFB): 17 were launched from VAFB (September 1961 – March 1965); one was destroyed in Beale AFB Site 851-C1 silo explosion 24 May 1962; 54 were based in Silos with SAC by 20 January 1965; 29 were in storage SBAMA (three at VAFB, one at each Base, including an extra at Lowry = 9 and 20 in storage at SBAMA elsewhere), a total of 101 production SM vehicles. The 83 surplus missiles remained in inventory at Mira Loma AFS. SM-65 Atlas missiles had already been converted to satellite launchers in the early 1960s, and the Titan I's had about the same payload capacity as an Atlas. It did not make economic sense to refurbish the 83 remaining missiles as launch vehicles. About 33 were distributed to museums, parks and schools as static displays (see list below). The remaining 50 missiles were scrapped at Mira Loma AFS near San Bernardino, CA, the last was broken up in 1972, in accordance with the SALT-I Treaty of 1 February 1972.
The official count is 101 Titan I Strategic Missiles produced: 17 Test launched, 1 lost, 50 destroyed Mira Loma, 33 at museum/display (some missing).
On 6 September 1985 Strategic Defense Initiative (AKA "Star Wars" program), a scrapped Titan I Second Stage was used in a Missile Defense test. The MIRACL Near Infrared Laser, at White Sands Missile Range, NM was fired at a stationary Titan I second stage that was fixed to ground. The second stage burst and was destroyed by the laser blast. The second stage did not contain any fuel or oxidizer. It was pressurized with nitrogen gas to 60-psi. A follow-up test 6 days later was conducted on a scrapped Thor IRBM, its remnants reside at the SLC-10 Museum at Vandenberg AFB.
Static displays and articles
There should be 33 Static Titan 1 Strategic Missiles and two (plus five possible) Research and Development Missiles to account for (of these 22 have been positively identified by Serial Number, eight known but need to be identified) and three are unaccounted for, missing.
- B2 57-2691 Cape Canaveral Air Force Space & Missile Museum, Florida Horizontal
Note: May have been at the 14th American Rocket Society meeting at a Wash, DC hotel on 1 Nov 59
- R&D (57–2743) Colorado State Capitol display 1959 (SN belongs to a Bomarc) Vertical
- R&D ? City of Lompoc, Lompoc Park (may have been V3 or BH) see below as possible SM. was Vertical, destroyed.
- R&D (1 of 2, poss. 6) Was at Patrick AFB Technical Laboratory, Satellite Beach, Florida. Vertical (destr. by Hurr. Erin 8/95)
then at Charlie Bell’s junkyard on US-1 Titusville, Fla., now Puerto Rico? (see below)
- R&D G-type Science and Technology Museum, Chicago 21 June 1963 Vertical
- SM-5 60-3650 Was on display at VAFB Armed Forces Day 1962, is this the Lompoc static? Horizontal
- SM-49 60-3694 Cordele, Georgia (west side of Route I-75). Vertical
- SM-53 60-3698 Site 395-C Museum, Vandenberg AFB, Lompoc, Ca. (from March AFB) Horizontal
- SM-54 60-3699 Strategic Air Command Museum, Bellevue, Nebraska (near Omaha). Vertical
- SM-61 60-3706 Gotte Park, Kimball, NE (only first stage standing, damaged by winds in ’96?) Vertical (damaged by winds 7/94 ?)
- SM-63 60-3708 In storage at Edwards AFB (still there?) Horizontal
- SM-65 61-4492 NASA Ames Research Center, Mountain View, California. Horizontal
- SM-67 61-4494 Titusville High School, Titusville, Florida (on Route US-1) removed was Horizontal
- SM-69 61-4496 (full missile) U.S. Space & Rocket Center (formerly Alabama Space and Rocket Center), Huntsville (stored outside, far west corner of center) Horizontal (in trees)
- SM-70 61-4497 Veterans Home, Quincy, IL Vertical (removed sent to DMAFB for destruction on May, 2010)
- SM-71 61-4498 U.S. Air Force Museum, now AMARC (to go to PIMA Mus.) Horizontal
- SM-72 61-4499 Florence Regional Airport Air and Space Museum, Florence, South Carolina. Horizontal
- SM-73 61-4500 former Holiday Motor Lodge, San Bernardino (now missing?). Horizontal
- SM-79 61-4506 former Oklahoma State Fair Grounds, Oklahoma City, Oklahoma. 1960s Horizontal
- SM-81 61-4508 Kansas Cosmosphere, Hutchinson, Kansas. In storage
- SM-86 61-4513 Beale AFB (not on display, was horizontal, removed 1994) Horizontal
- SM-88 61-4515 (st. 1) Pima Air & Space Museum, outside DM AFB, Tucson, Arizona, now WPAFB Horizontal
- SM-89 61-4516 (st. 2) Pima Air Museum, outside DM AFB, Tucson, Arizona, now WPAFB Horizontal
- SM-92 61-4519 (st. 1) Kansas Cosmosphere, Hutchinson, Kansas. (acq. 11/93 from MCDD) Vertical (st 1 mate to SM-94 st 1)
- SM-93 61-4520 (st. 2) SLC-10 Museum, Vandenberg AFB, Lompoc, Ca. Horizontal (only stage 2)
- SM-94 61-4521 (st. 1) Kansas Cosmosphere, Hutchinson, Kansas. (acq. 6/93 from MCDD) Vertical (st 1 mate to SM-92 st 1)
- SM-96 61-4523 South Dakota Air and Space Museum, Ellsworth AFB, Rapid City, South Dakota. Horizontal
- SM-101 61-4528 Estrella Warbirds Museum, Paso Robles, CA (2nd stage damaged) Horizontal
- SM- ? ? (full missile) Ingram Park, town of Lompoc, Ca. (with a Nike Target Warhead) was vertical, destroyed
- SM- ? ? (stg. 2 only) former SDI laser test target (whereabouts?) is this 4519 & or 4521 stg 1? Horizontal (remnants of stage 1)
- SM- ? ? (stg. 1 only) former Spaceport USA Rocket Garden, Kennedy Space Center, Florida. Vert. (stg 1 mated to stg 1 below)
- SM- ? ? (stg. 1 only) former Spaceport USA Rocket Garden, Kennedy Space Center, Florida. Vert. (stg 1 mated to stg 1 above)
- SM- ? ? (stg. 1 only) Science Museum, Bayamon, Puerto Rico (PAFB R&D/Bell’s ??) Vert. (stg 1 mated to stg 1 below)
- SM- ? ? (stg. 1 only) Science Museum, Bayamon, Puerto Rico (top half from Bell’s Junkyard) Vert. (stg 1 mated to stg 1 above)
- SM- ? ? (full missile) former Outside main gate of White Sands Missile Range, N.M. false report? Vertical
- SM- ? ? (full missile) Spacetec CCAFS Horizontal
Note: Two stacked Titan-1 first stages created a perfect illusion of a Titan-2 Missile for museums above.
- Air Force Systems Command The Development of the SM-68 Titan, Wright-Patterson Air Force Base: Air Force Systems Command, 1962, AFSC Historical Publications Series 62-23-1, p. 6.
- Air Force Systems Command The Development of the SM-68 Titan, Wright-Patterson Air Force Base: Air Force Systems Command, 1962, AFSC Historical Publications Series 62-23-1, p. 17.
- "Titan Missile". Strategic-Air-Command.com. Retrieved 2016-06-02. Check date values in:
- Hoselton, Gary A., Titan I Guidance System, Brekenridge, Colorado: Association of Air Force Missileers, Volume 6, Number 1998, p. 4.
- Guidance Changes Made on Atlas, Titan, Aviation Week July 28, 1958, page 22
- Titan Guidance Switch, Aviation Week April 6, 195, page 31
- Hoselton, Gary A., Titan I Guidance System, Brekenridge, Colorado: Association of Air Force Missileers, Volume 6, Number 1, 1998, p. 4.
- United States Air Force The T.O. 21M-HGM25A-1-1 Technical Manual Operation and Organizational Maintenance HGM-25A Missile Weapon System, United States Air Force, 1964, paragraph 1-159 - 1-161
- Hoselton, Gary A., Titan I Guidance System, Brekenridge, Colorado: Association of Air Force Missileers, Volume 6, Number 1, 1998, p. 5.
- Hoselton, Gary A., Titan I Guidance System, Brekenridge, Colorado: Association of Air Force Missileers, Volume 6, Number 1, 1998, p. 4.
- United States Air Force The T.O. 21M-HGM25A-1-1 Technical Manual Operation and Organizational Maintenance HGM-25A Missile Weapon System, United States Air Force, 1964, paragraph 1-173
- Walker,Chuck Atlas The Ultimate Weapon, Burlington Canada: Apogee Books, 2005, ISBN 0-517-56904-3, p. 11
- Green Warren E. The Development of the SM-68 Titan, Wright-Patterson Air Force Base: Air Force Systems Command, 1962, AFSC Historical Publications Series 62-23-1, p. 17.
- Hansen, Chuck, Swords of Armageddon, 1995, Chukelea Publications, Sunnyvale, California, page Volume VII Page 293
- missilebases.com (2011). "History of Missile Bases". missilebases.com. Retrieved 4 September 2011.
- Tri-City Herald article by Kristin Alexander about Titan 1 complexes in Washington State
- Information on "Northern California Triad" of Titan missile bases in Lincoln, California; Chico, California and Live Oak, Sutter County, California (Sutter Buttes)
- Titan 1 Upgrade Project at NASA Moffett Field
|Wikimedia Commons has media related to Titan (Rocket).|
- Related lists