Atlas III

Atlas III

The maiden flight of the Atlas III
Function	Medium expendable Launch vehicle
Manufacturer	Lockheed Martin
Country of origin	United States
Size
Height	52.8 m (173.2 ft)
Diameter	3.05 m (10 ft)
Mass	214,338 kg (472,338 lb)
Stages	2
Capacity
Payload to LEO	IIIA: 8,640 kg (19,040 lb) IIIB: 10,218 kg (23,630 lb)
Payload to GTO	IIIA: 4,055 kg (8,939 lb) IIIB: 4,500 kg (9,900 lb)
Associated rockets
Family	Atlas
Launch history
Status	Retired
Launch sites	SLC-36B, CCAFS
Total launches	6 (IIIA: 2, IIIB: 4)
Successes	6 (IIIA: 2, IIIB: 4)
First flight	IIIA: 24 May 2000 IIIB: 21 February 2002
Last flight	IIIA: 13 March 2004 IIIB: 3 February 2005
First stage
Engines	1 RD-180
Thrust	4,148.7 kN (932,670 lbf)
Specific impulse	311 sec
Burn time	132 seconds
Fuel	RP-1/LOX
Second stage (Atlas IIIA) - Centaur (SEC)
Engines	1 RL-10A
Thrust	99.2 kN (22,290 lbf)
Specific impulse	451 sec
Burn time	738 seconds
Fuel	LH2/LOX
Second stage (Atlas IIIB) - Centaur (DEC)
Engines	2 RL-10A
Thrust	147 kN (41,592 lbf)
Specific impulse	449 sec
Burn time	392 seconds
Fuel	LH2/LOX

The Lockheed Martin Atlas III (known as the Atlas II-AR early in development) was an American orbital launch vehicle, used between 2000 and 2005. It was the first member of the Atlas family since the Atlas A to feature a "normal" staging method, compared to the previous Atlas family members, which were equipped with jettisonable engines on the first (sustainer) stage.

Description

The Atlas III consisted of two stages. The first stage was new, but the upper stage was the Centaur, which is still in use today on the Atlas V EELV. The first stage engines were Russian RD-180s, which are also used by the Atlas V. The Atlas III was produced in two versions. The baseline was the Atlas IIIA, but the Atlas IIIB, featuring a twin-engine version of the Centaur upper stage, was also produced.

Launches

The maiden flight of the Atlas III occurred on May 24, 2000, launching the Eutelsat W4 communications satellite into a geosynchronous orbit. All Atlas III launches were made from Space Launch Complex 36B at Cape Canaveral Air Force Station. The Atlas III made its sixth and last flight on February 3, 2005, with a classified payload for the United States National Reconnaissance Office.

GX

Main article: GX (rocket)

The GX rocket, formerly under development by Galaxy Express Corporation, was originally intended to use the boost stage of the Atlas III, provided by Lockheed-Martin, and a newly designed upper stage. It would have launched from the Tanegashima Space Center, south of Kyūshū, Japan. In December 2009 the Japanese government decided to cancel the GX project.

See also

• Comparison of orbital launchers families