|Function||Orbital launch vehicle|
(design, manufacturing and assembly)
Mitsubishi Heavy Industries
(extended kerosene tank and H-IIA-based upper stage manufacturing)
|Country of origin||United States|
|Height||35 m (115 ft)|
|Diameter||4 m (13 ft)|
|Mass||301,450 kg (664,580 lb)|
|Payload to LEO|
|Mass||8,290 kg (18,280 lb)|
|Payload to GTO|
|Mass||3,810 kg (8,400 lb)|
|Launch sites||SLC-17B, Cape Canaveral|
|First flight||August 26, 1998|
|Last flight||August 23, 2000|
|No. boosters||9 GEM 46|
|Maximum thrust||628.3 kN (141,200 lbf)|
|Specific impulse||273 seconds (2.68 km/s)|
|Burn time||75 seconds|
|Propellant||HTPB bound APCP|
|Powered by||1 Rocketdyne RS-27A|
|Maximum thrust||1,085.79 kN (244,100 lbf)|
|Specific impulse||254 seconds (2.49 km/s)|
|Burn time||260 seconds|
|Powered by||1 Pratt & Whitney RL10B|
|Maximum thrust||110.03 kN (24,740 lbf)|
|Specific impulse||462 seconds (4.53 km/s)|
|Burn time||700 seconds|
|Third stage (Optional)|
|Powered by||1 Thiokol Star 48B|
|Maximum thrust||66.723 kN (15,000 lbf)|
|Specific impulse||286 seconds (2.80 km/s)|
|Burn time||87 seconds|
Delta III was an expendable launch vehicle made by Boeing. The vehicle was developed from the highly-successful Delta II to help meet the launch demand of larger satellites. The first Delta III launch was on August 26, 1998. Of its three flights, the first two were failures, and the third, though declared successful, reached the low end of its targeted orbit range and carried only a dummy (inert) payload. The Delta III could deliver up to 3,810 kg (8,400 lb) to geostationary transfer orbit, twice the payload of its predecessor, the Delta II. Under the four-digit designation system from earlier Delta rockets, the Delta III is classified as the Delta 8930.
Delta III was developed from the Delta II rocket. The new vehicle sported a somewhat similar first stage, but a new, more efficient upper stage. This led to Delta III having around double the payload capacity of Delta II. However, the consecutive failures of the initial Delta IIIs, combined with the more advanced Delta IV program and the continuing success of the Delta II, left the Delta III as an interim vehicle.
Like the Delta II, the first stage of the Delta III burned kerosene and liquid oxygen and was powered by one Rocketdyne RS-27A main engine with two vernier engines for roll control. The vernier engines were also used for attitude control after the main engine shut off, just before the second stage separated. While the propellant load and gross mass of the stage were nearly identical to the Delta II, the diameter of the kerosene tank was increased from 2.4 meters to 4 meters, while its height was reduced. The liquid oxygen tank and engine section remained largely unchanged. The redesigned kerosene tank reduced the overall length of the stage and, combined with the increased height of the second stage, allowed the Delta III to use the same launch facilities as the Delta II with only minor modifications.
The first stage thrust was augmented by nine GEM-46 solid rocket boosters, sometimes referred to as GEM LDXL (Large Diameter Extended Length). These were 14.7 m (48 ft) meters in length, 1.2 m (46 inches) in diameter, and had a mass of 19 metric tons each, about six metric tons more than the Delta II's standard GEM-40 motors. Six were ignited on the launch pad, while the remaining three were ignited just before burnout and separation of the ground-lit boosters. To maintain steering authority, three of the ground-lit boosters had vectoring nozzles. GEM-46 boosters would later find use on the Delta II, leading to the Delta II Heavy.
The second stage of the Delta III was the newly developed Delta Cryogenic Second Stage (DCSS), which burned liquid hydrogen and liquid oxygen. It was developed and manufactured partly by Mitsubishi Heavy Industries and was based on the second stage of the H-IIA rocket. The liquid hydrogen tank was 4 m (13 ft) meters in diameter, while the separate liquid oxygen tank (attached by a truss to the bottom of the hydrogen tank) was 2.4 m (7 ft 10 in) meters in diameter. This stage offered significantly better performance than the Delta II's second stage, the Delta-K, which burned hypergolic propellants. The DCSS was powered by a Pratt & Whitney RL10B-2 engine, derived from the RL10 powering the Centaur upper stage but featuring electromechanical actuators for gimbal control and an extending nozzle for increased specific impulse. After Delta III's retirement, this stage was modified for use as the Delta IV's second stage.
Delta III was offered with an optional third stage, the Star 48B solid rocket motor. It would have been attached on top of the DCSS and contained inside the payload fairing. The stage would have been used for high-energy orbits, like interplanetary missions. It was never flown on Delta III but was commonly used on Delta II missions. It has also seen use on Delta IV and Atlas V.
The payload fairing was a new composite design, matching the upper stage hydrogen tank's 4 m (13 ft) diameter and allowing larger payloads than the Delta II's 9.5 or 10-foot-diameter fairing. Delta III's 4-meter fairing was derived from Delta II's 10 ft composite fairing. This fairing design would later be repurposed on the Delta IV Medium.
|Flight Number||Date / time (UTC)||Rocket
|Launch site||Payload||Payload mass||Orbit||Customer||Launch |
|1||August 27, 1998
|Delta 3 8930||CCAFS SLC-17B||Galaxy 10||1,543 pounds (700 kilograms)||GTO||PanAmSat / Intelsat||Failure|
|Maiden flight of Delta 3 8930, Destroyed by range safety after control problems and depletion of hydraulic fluid, Communications satellite.|
|2||May 5, 1999
|Delta 3 8930||CCAFS SLC-17B||Orion 3||9,480 pounds (4,300 kilograms)||GTO||Loral||Failure|
|Second stage engine failure. Payload placed in too low a LEO, Loral declared satellite lost. Communications satellite.|
|3||August 23, 2000
|Delta 3 8930||CCAFS SLC-17B||DM-F3||9,663 pounds (4,383 kilograms)||GTO||US Air Force||Partial failure|
|Reached lower than planned orbit, final flight of Delta 3 8930, Demosat.|