Тита́н IV: Аме́риканская раке́та-но́ситель тяжёлого кла́сса

Expendable launch system used by the US Air Force

Titan IV was a family of heavy lift space launch vehicles developed by Martin Marietta and operated by the United States Air Force from 1989 to 2005. Launches were conducted from Cape Canaveral Air Force Station, Florida and Vandenberg Air Force Base, California. The Titan IV was the last of the Titan family of rockets, originally developed by the Glenn L. Martin Company in 1958. It was retired in 2005 due to their high cost of operation and concerns over its toxic hypergolic propellants, and replaced with the Atlas V and Delta IV launch vehicles under the EELV program. The final launch (B 30) from Cape Canaveral occurred on 29 April 2005, and the final launch from Vandenberg AFB occurred on 19 October 2005. Lockheed Martin Space Systems built the Titan IVs near Denver, Colorado, under contract to the US government.

The Titan IV B evolved from the Titan III family and was similar to the Titan 34D. While the launcher family had an extremely good reliability record in its first two decades, this changed in the 1980s with the loss of a Titan 34D in 1985 followed by the disastrous explosion of another in 1986 due to a SRM failure. Due to this, the Titan IV B vehicle was intended to use the new composite casing Upgraded Solid Rocket Motors. Due to development problems the first few Titan IV B launches flew with the old style UA1207 SRMs.

In 1988–89, The R. M. Parsons Company designed and built a full scale steel tower and deflector facility, which was used to test the Titan IV Solid Rocket Motor Upgrade (SRMU). The launch and the effect of the SRMU thrust force on the Titan IV vehicle were modeled. To evaluate the magnitude of the thrust force, the SRMU was connected to the steel tower through load measurement systems and launched in place. It was the first full scale test conducted to simulate the effects of the SRMU on the Titan IV vehicle.

In the early 1980s, General Dynamics developed a plan to assemble a lunar landing spacecraft in orbit under the name Early Lunar Access. A Space Shuttle would lift a lunar lander into orbit and then a Titan IV rocket would launch with a modified Centaur G Prime stage to rendezvous and dock. The plan required upgrading the Space Shuttle and Titan IV to use lighter aluminium lithium alloy propellant tanks. The plan never came to fruition, but in the 1990s the Shuttle's External Tank was converted to aluminum lithium tanks to rendezvous with the highly inclined orbit of the Russian Mir Space Station.

The IV A (40nA) used boosters with steel casings, the IV B (40nB) used boosters with composite casings (the SRMU). Type 401 used a Centaur 3rd stage, type 402 used an IUS 3rd stage. The other 3 types (without 3rd stages) were 403, 404, and 405:

Type 403 featured no upper stage, for lower mass payloads to higher orbits from Vandenberg. Type 404 featured no upper stage, for heavier payloads to low orbits, from Vandenberg. the rocket would only carry three military payloads paired with Centaur stages and fly exclusively from LC 41 at Cape Canaveral. However, the Challenger accident in 1986 caused a renewed dependence on expendable launch systems, with the Titan IV program significantly expanded. At the time of its introduction, the Titan IV was the largest and most capable expendable launch vehicle used by the USAF. The post Challenger program added Titan IV versions with the Inertial Upper Stage (IUS) or no upper stages, increased the number of flights, and converted LC 40 at the Cape for Titan IV launches. As of 1991, almost forty total Titan IV launches were scheduled and a new, improved SRM (solid rocket motor) casing using lightweight composite materials was introduced.

In 1990, the Titan IV Selected Acquisition Report estimated the total cost for the acquisition of 65 Titan IV vehicles over a period of 16 years to US$18.3 billion (inflation adjusted US$ billion in ).

In October 1997, a Titan IV B rocket launched Cassini–Huygens, a pair of probes sent to Saturn. It was the only use of a Titan IV for a non Department of Defense launch. Huygens landed on Titan on January 14, 2005. Cassini remained in orbit around Saturn. The Cassini Mission ended on September 15, 2017, when the spacecraft was sent into Saturn's atmosphere to burn up.

While an improvement over the shuttle, the Titan IV was expensive and unreliable. By the 1990s, there were also growing safety concerns over its toxic propellants. The Evolved Expendable Launch Vehicle (EELV) program resulted in the development of the Atlas V, Delta IV, and Delta IV Heavy launch vehicles, which replaced Titan IV and a number of other legacy launch systems. The new EELVs eliminated the use of hypergolic propellants, reduced costs, and were much more versatile than the legacy vehicles.

In 2014, the National Museum of the United States Air Force in Dayton, Ohio, began a project to restore a Titan IV B rocket. This effort was successful, with the display opening June 8, 2016. The only other surviving Titan IV components are at the Wings Over the Rockies Air and Space Museum in Denver, Colorado which has two Titan Stage 1 engines, one Titan Stage 2 engine, and the interstage ‘skirt’ on outdoor display; and at the Evergreen Aviation and Space Museum in McMinnville, Oregon, including the core stages and parts of the solid rocket motor assembly.

Date / Time (UTC) Launch Site S/N Type Payload Outcome Remarks 14 June 1989 13:18 CCAFS LC 41 K 1 402A / IUS USA 39 (DSP 14) An engine bell burn through left only a narrow margin for success. 8 June 1990 05:21 CCAFS LC 41 K 4 405A USA 60 (NOSS)USA 61 (NOSS)USA 62 (NOSS)USA 59 Satellite Launch Dispenser Communications (SLDCOM) 13 November 1990 00:37 CCAFS LC 41 K 6 402A / IUS USA 65 (DSP 15) 8 March 1991 12:03 VAFB LC 4E K 5 403A USA 69 (Lacrosse) 8 November 1991 07:07 VAFB LC 4E K 8 403A USA 74 (NOSS)USA 76 (NOSS)USA 77 (NOSS)USA 72 SLDCOM 28 November 1992 21:34 VAFB LC 4E K 3 404A USA 86 (KH 11) 2 August 1993 19:59 VAFB LC 4E K 11 403A NOSS x3 SLDCOM SRM exploded at T+101s due to damage caused during maintenance on ground. 7 February 1994 21:47 CCAFS LC 40 K 10 401A / Centaur USA 99 (Milstar 1) 3 May 1994 15:55 CCAFS LC 41 K 7 401A / Centaur USA 103 (Trumpet) 27 August 1994 08:58 CCAFS LC 41 K 9 401A / Centaur USA 105 (Mercury) 22 December 1994 22:19 CCAFS LC 40 K 14 402A / IUS USA 107 (DSP 17) 14 May 1995 13:45 CCAFS LC 40 K 23 401A / Centaur USA 110 (Orion) 10 July 1995 12:38 CCAFS LC 41 K 19 401A / Centaur USA 112 (Trumpet) 6 November 1995 05:15 CCAFS LC 40 K 21 401A / Centaur USA 115 (Milstar 2) 5 December 1995 21:18 VAFB LC 4E K 15 404A USA 116 (KH 11) 24 April 1996 23:37 CCAFS LC 41 K 16 401A / Centaur USA 118 (Mercury) 12 May 1996 21:32 VAFB LC 4E K 22 403A USA 120 (NOSS)USA 121 (NOSS)USA 122 (NOSS)USA 119 (SLDCOM)USA 123 Tethers in Space Physics Satellite (TiPS)USA 124 (TiPS) 3 July 1996 00:30 CCAFS LC 40 K 2 405A USA 125 (SDS) 20 December 1996 18:04 VAFB LC 4E K 13 404A USA 129 (KH 11) NROL 2 23 February 1997 20:20 CCAFS LC 40 B 24 402B / IUS USA 130 (DSP 18) 15 October 1997 08:43 CCAFS LC 40 B 33 401B / Centaur CassiniHuygens 24 October 1997 02:32 VAFB LC 4E A 18 403A USA 133 (Lacrosse) NROL 3 8 November 1997 02:05 CCAFS LC 41 A 17 401A / Centaur USA 136 (Trumpet) NROL 4 9 May 1998 01:38 CCAFS LC 40 B 25 401B / Centaur USA 139 (Orion) NROL 6 12 August 1998 11:30 CCAFS LC 41 A 20 401A / Centaur NROL 7 (Mercury) Guidance system short circuited at T+40s due to frayed wire, vehicle lost control and destroyed by range safety. 9 April 1999 17:01 CCAFS LC 41 B 27 402B / IUS USA 142 (DSP 19) Spacecraft failed to separate from IUS stage. 30 April 1999 16:30 CCAFS LC 40 B 32 401B / Centaur USA 143 (Milstar 3) Centaur software database error caused loss of attitude control, insertion burns done incorrectly. Satellite deployed into useless orbit. 22 May 1999 09:36 VAFB LC 4E B 12 404B USA 144 (Misty) NROL 8 8 May 2000 16:01 CCAFS LC 40 B 29 402B / IUS USA 149 (DSP 20) 17 August 2000 23:45 VAFB LC 4E B 28 403B USA 152 (Lacrosse) NROL 11 27 February 2001 21:20 CCAFS LC 40 B 41 401B / Centaur USA 157 (Milstar 4) 6 August 2001 07:28 CCAFS LC 40 B 31 402B / IUS USA 159 (DSP 21) 5 October 2001 21:21 VAFB LC 4E B 34 404B USA 161 (KH 11) NROL 14 16 January 2002 00:30 CCAFS LC 40 B 38 401B / Centaur USA 164 (Milstar 5) 8 April 2003 13:43 CCAFS LC 40 B 35 401B / Centaur USA 169 (Milstar 6) 9 September 2003 04:29 CCAFS LC 40 B 36 401B / Centaur USA 171 (Orion) NROL 19 14 February 2004 18:50 CCAFS LC 40 B 39 402B / IUS USA 176 (DSP 22) 30 April 2005 00:50 CCAFS LC 40 B 30 405B USA 182 (Lacrosse) NROL 16 19 October 2005 18:05 VAFB LC 4E B 26 404B USA 186 (KH 11) NROL 20

The Titan IV experienced four catastrophic launch failures.

On August 2, 1993, Titan IV K 11 lifted from SLC 4E carrying a NOSS SIGNIT satellite. Unusually for DoD launches, the Air Force invited civilian press to cover the launch, which became more of a story than intended when the booster exploded 101 seconds after liftoff. Investigation found that one of the two SRMs had burned through, resulting in the destruction of the vehicle in a similar manner as the earlier 34D 9 failure. An investigation found that an improper repair job was the cause of the accident. After Titan 34D 9, extensive measures had been put in place to ensure proper SRM operating condition, including X raying the motor segments during prelaunch checks. The SRMs that went onto K 11 had originally been shipped to Cape Canaveral, where X rays revealed anomalies in the solid propellant mixture in one segment. The defective area was removed by a pie shaped cut in the propellant block. However, most of CSD's qualified personnel had left the program by this point and so the repair crew in question did not know the proper procedure. After replacement, they neglected to seal the area where the cut in the propellant block had been made. Post repair X rays were enough for CC personnel to disqualify the SRMs from flight, but the SRMs were then shipped to Vandenberg and approved anyway. The result was a near repeat of 34D 9; a gap was left between the propellant and SRM casing and another burn through occurred during launch.

1998 saw the failure of Titan K 17 with a Navy ELINT Mercury (satellite) from Cape Canaveral around 40 seconds into the flight. K 17 was several years old and the last Titan IV A to be launched. The post accident investigation showed that the booster had dozens of damaged or chafed wires and should never have been launched in that operating condition, but the Air Force had put extreme pressure on launch crews to meet program deadlines. The Titan's fuselage was filled with numerous sharp metal protrusions that made it nearly impossible to install, adjust, or remove wiring without it getting damaged. Quality control at Lockheed's Denver plant, where Titan vehicles were assembled, was described as "awful". The proximal cause of the failure was an electrical short that caused a momentary power dropout to the guidance computer at T+39 seconds. After power was restored, the computer sent a spurious pitch down and yaw to the right command. At T+40 seconds, the Titan was traveling at near supersonic speed and could not handle this action without suffering a structural failure. The sudden pitch downward and resulting aerodynamic stress caused one of the SRMs to separate. The ISDS (Inadvertent Separation Destruct System) automatically triggered, rupturing the SRM and taking the rest of the launch vehicle with it. At T+45 seconds, the Range Safety Officer sent the destruct command to ensure any remaining large pieces of the booster were broken up. An extensive recovery effort was launched, both to diagnose the cause of the accident and recover debris from the classified satellite. All of the debris from the Titan had impacted offshore, between three and five miles downrange, and at least 30% of the booster was recovered from the sea floor. Debris continued to wash ashore for days afterward, and the salvage operation continued until October 15. The Air Force had pushed for a "launch on demand" program for DOD payloads, something that was almost impossible to pull off especially given the lengthy preparation and processing time needed for a Titan IV launch (at least 60 days). Shortly before retiring in 1994, General Chuck Horner referred to the Titan program as "a nightmare". The 1998 99 schedule had called for four launches in less than 12 months. The first of these was Titan K 25 which successfully orbited an Orion SIGNIT satellite on May 9, 1998. The second was the K 17 failure, and the third was the K 32 failure.

After a delay caused by the investigation of the previous failure, the 9 April 1999 launch of K 32 carried a DSP early warning satellite. The IUS second stage failed to separate, leaving the payload in a useless orbit. Investigation into this failure found that wiring harnesses in the IUS had been wrapped too tightly with electrical tape so that a plug failed to disconnect properly and prevented the two IUS stages from separating.

The fourth launch was K 26 on April 30, 1999, carrying a Milstar communications satellite. During the Centaur coast phase flight, the roll control thrusters fired open loop until the RCS fuel was depleted, causing the upper stage and payload to rotate rapidly. On restart, the Centaur cartwheeled out of control and left its payload in a useless orbit. This failure was found to be the result of an incorrectly programmed equation in the guidance computer. The error caused the roll rate gyro data to be ignored by the flight computer.