Titan 23G

The Titan 23G, Titan II(23)G, Titan 2(23)G or Titan II SLV was an American expendable launch system derived from the LGM-25C Titan II intercontinental ballistic missile. Retired Titan II missiles were converted by Martin Marietta, into which the Glenn L. Martin Company, which built the original Titan II, had merged. It was used to carry payloads for the United States Air Force, NASA and NOAA. Thirteen were launched from Space Launch Complex 4W at the Vandenberg Air Force Base between 1988 and 2003.[1]

Titan 23G rockets consisted of two stages burning liquid propellant. The first stage was powered by one Aerojet LR87 engine with two combustion chambers and nozzles, and the second stage was propelled by an LR91. On some flights, solid upper stages were flown, usually the Star-37XFP-ISS; however, the Star-37S was also used.[1]

A contract to refurbish fourteen Titan II missiles to the Titan 23G configuration was awarded to Martin Marietta in January 1986. The first launch occurred on 5 September 1988, carrying a classified payload for the US National Reconnaissance Office. Thirteen were launched, with the fourteenth going to the Evergreen Aviation Museum.[2] The final flight occurred on 17 October 2003, carrying a DMSP satellite.[3]

During refurbishment, the forward structure of the second stage was modified with the addition of a payload attachment fitting to attach the payload to the rocket, and installing a payload fairing to protect it during launch. The engines were refurbished, and the rockets' guidance and control systems were upgraded by Delco Electronics.

The former Titan IIIB pad at Vandenberg, SLC-4W, was modified to accommodate the Titan 23G, and was used for all thirteen launches.

Titan 23G
Titan 23G rocket
The first Titan 23G prior to launch
Function Expendable launch system
Manufacturer Martin Marietta
Country of origin United States
Height 31.4 meters (103 ft)
Diameter 3.05 meters (10.0 ft)
Mass 117,020 kilograms (257,980 lb)
Stages Two or Three
Payload to LEO 3,600 kilograms (7,900 lb)
Payload to Polar LEO 2,177 kilograms (4,799 lb)
Payload to HCO 227 kilograms (500 lb)
Associated rockets
Family Titan
Launch history
Status Retired
Launch sites Vandenberg SLC-4W
Total launches 13
Successes 12
Failures 1
First flight 5 September 1988
Last flight 18 October 2003
Notable payloads Clementine
First stage
Engines LR-87 (one engine with two combustion chambers)
Thrust 1,900 kilonewtons (430,000 lbf)
Specific impulse 258 sec
Burn time 156 seconds
Fuel A-50/N2O4
Second stage
Engines 1 LR-91
Thrust 445 kilonewtons (100,000 lbf)
Specific impulse 316 sec
Burn time 180 seconds
Fuel A-50/N2O4
Third stage (Optional) – Star-37XFP-ISS
Engines 1 Solid
Thrust 38.03 kilonewtons (8,550 lbf)
Specific impulse 290 sec
Burn time 67 seconds
Fuel Solid
Third stage (Optional) – Star-37S
Engines 1 Solid
Specific impulse 287 sec
Fuel Solid


All launches of Titan II(23)G rockets took place from Space Launch Complex 4W at Vandenberg Air Force Base.

Date/Time (UTC) Serial number Third Stage Payload Outcome Remarks
Rocket Stages
5 September 1988
G-1 B-98/56 None USA-32 (Bernie) Successful
6 September 1989
G-2 B-75/99 None USA-45 (Bernie) Successful Spacecraft failed immediately after launch
25 April 1992
G-3 B-102 None USA-81 (Bernie) Successful
5 October 1993
G-5 B-65 Star-37XFP-ISS Landsat 6 Failure[4] Star-37 failure, failed to achieve orbit[5]
25 January 1994
G-11 B-89/67 None Clementine
4 April 1997
G-6 B-106 Star-37S-ISS USA-131 (DMSP-5D2 F-14) Successful
13 May 1998
G-12 B-84/80 Star-37XFP-ISS NOAA-15 (NOAA-K) Successful Included oxygen tank from Titan II B-72
20 June 1999
G-7 B-99/75 None QuikSCAT Successful
12 December 1999
G-8 B-94/44 Star-37XFP-ISS USA-147 (DMSP-5D3 F-15) Successful
21 September 2000
G-13 B-96/39 Star-37XFP-ISS NOAA-16 (NOAA-L) Successful
24 June 2002
G-14 B-71/72 Star-37XFP-ISS NOAA-17 (NOAA-M) Successful Included oxygen tank from Titan II B-92
6 January 2003
G-4 B-105 None Coriolis Successful
18 October 2003
G-9 B-107 Star-37XFP-ISS USA-172 (DMSP-5D3 F-16) Successful Final Titan II launch

A fourteenth rocket, G-10, based on Titan II B-108, but incorporating an oxygen tank from B-80, was not launched and is preserved at the Evergreen Aviation & Space Museum in McMinnville, Oregon. The remaining 42 Titan II missiles were stored at Davis-Monthan AFB with most being broken up for salvage. Four were transferred to museums.

T2 01 G1

01 Titan-23G01 BERNIE-1 ELINT satellite

04 Titan-23G05 LANDSAT-6

Titan 23G launches Clementine

05 Titan-23G11 CLEMENTINE

T2 06 G6 DMSP F14

06 Titan-23G06 DMSP-F14

T2 07 G12 NOAA-K

07 Titan-23G12 NOAA-K

T2 08 G7 QuickSCAT

08 Titan-23G07 QuickSCAT

09 Titan-23G08 DMSP-F15

T2 10 G13 NOAA-L

10 Titan-23G13 NOAA-L

T2 11 G14 NOAA-M

11 Titan-23G14 NOAA-M

T2 12 G4 Coriolis

12 Titan-23G04 CORIOLIS


13 Titan-23G09 DMSP-F16

Titan-II B-108 became 23G10

Titan-II B-108 in 1988 became 23G10 program spare

See also

Media related to Titan (rocket) at Wikimedia Commons


  1. ^ a b Krebs, Gunter. "Titan-2". Gunter's Space Page. Retrieved 2009-04-29.
  2. ^ Kyle, Ed (2009-04-14). "Titan 23G Data Sheet". Space Launch Report. Retrieved 2009-04-29.
  3. ^ Wade, Mark. "Titan". Encyclopedia Astronautica. Retrieved 2009-04-29.
  4. ^ Kyle, Ed. "Titan Launch History". Space Launch Report. p. 3. Retrieved 24 January 2014.
  5. ^ Wade, Mark. "Landsat 6". Encyclopedia Astronautica. Retrieved 24 January 2014.

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