The Titan IIID or Titan 3D was an American expendable launch system, part of the Titan rocket family. Titan IIID was flown 22 times with KH-9 and KH-11 satellites between 1971 and 1982, all successful launches.^[1] Essentially a Titan IIIC with the Transtage removed, it was designed for heavy LEO payloads.

Launch of a Titan IIID
Function	Expendable launch system
Manufacturer	Martin Marietta
Country of origin	United States
Size
Height	36 m (118 ft)
Diameter	3.05 m (10.0 ft)
Mass	612,990 kg (1,351,410 lb)
Stages	Two
Capacity
Payload to LEO
Mass	12,300 kg (27,100 lb)
Associated rockets
Family	Titan
Launch history
Status	Retired
Launch sites	SLC-4E, Vandenberg AFB
Total launches	22
Success(es)	22
First flight	15 June 1971
Last flight	17 November 1982
Boosters (Stage 0) – UA1205
No. boosters	Two
Powered by	off
Maximum thrust	5,849 kN (1,315,000 lbf)
Specific impulse	263 sec
Burn time	115 seconds
Propellant	Solid
First stage
Powered by	2 LR87-11
Maximum thrust	2,340 kN (530,000 lbf)
Specific impulse	302 sec
Burn time	147 seconds
Propellant	N2O4 / Aerozine 50
Second stage
Powered by	1 LR91-11
Maximum thrust	454 kN (102,000 lbf)
Specific impulse	316 sec
Burn time	205 seconds
Propellant	N2O4 / Aerozine 50
[edit on Wikidata]

Part of the Titan rocket family, the Titan IIID first flew on 15 June 1971, launching the first KH-9 satellite.^[2] It was retired from service in 1982, and replaced by the uprated Titan 34D. All launches occurred from Space Launch Complex 4E at Vandenberg Air Force Base.