Delta IV

Delta IV (Delta 9000)
Size
Delta IV Medium launch carrying DSCS III-B6
Function	Orbital launch vehicle
Manufacturer	Boeing BDS United Launch Alliance
Country of origin	United States
Height	63-72 m (206-235 ft)
Diameter	5 m (16.4 ft)
Mass	249,500-733,400 kg (550,000-1,616,800 lb)
Stages	2
Capacity
Payload to LEO	9,420-28,790 kg (20,750-63,450 lb)
Payload to GTO	4,440-14,220 kg (8,500-28,620 lb)
Launch history
Status	Active
Launch sites	SLC-37B, Cape Canaveral SLC-6, Vandenberg AFB
Total launches	34 Medium: 3 Medium+ (4,2): 14 Medium+ (5,2): 2 Medium+ (5,4): 6 Heavy: 9
Successes	33 Medium: 3 Medium+ (4,2): 14 Medium+ (5,2): 2 Medium+ (5,4): 6 Heavy: 8
Partial failures	1 (Heavy)
First flight	Medium: March 11, 2003 Medium+ (4,2): November 20, 2002 Medium+ (5,2): April 3, 2012 Medium+ (5,4): December 6, 2009 Heavy: December 21, 2004
Last flight	Medium: November 4, 2006 - DMSP F17 Medium+ (4,2): August 19, 2016 - AFSPC-6 Medium+ (5,2): February 10, 2016 - NROL-45 Medium+ (5,4): December 7, 2016 - WGS-8 Heavy: June 11, 2016 - NROL-37

Boosters (Medium+) - GEM 60
No. boosters	Medium+ (4,2), Medium+ (5,2): 2 Medium+ (5,4): 4
Gross mass	33,638 kg (74,158 lb)
Thrust	826.6 kN (185,800 lb_f)
Specific impulse	245 s (sea level)
Burn time	91 seconds
Fuel	HTPB
Boosters (Heavy) - CBC
No. boosters	2
Gross mass	226,400 kg (499,100 lb)
Engines	1 RS-68A
Thrust	3,140 kN (705,000 lbf) (sea level)
Specific impulse	Sea level: 360 sec Vacuum: 412 sec
Burn time	242 seconds
Fuel	LH2/LOX
First stage - CBC
Gross mass	226,400 kg (499,100 lb)
Engines	1 RS-68A
Thrust	3,140 kN (705,000 lbf) (sea level)
Specific impulse	Sea level: 360 sec Vacuum: 412 sec
Burn time	245 seconds (328 seconds in Heavy configuration)
Fuel	LH2/LOX
Second stage - DCSS
Gross mass	4-m: 24,170 kg (53,290 lb) 5-m: 30,700 kg (67,700 lb)
Engines	1 RL10-B-2
Thrust	110 kN (25,000 lbf)
Specific impulse	462 s
Burn time	850-1,125 seconds
Fuel	LH2/LOX

Delta IV is an expendable launch system in the Delta rocket family. The rocket's main components are designed by Boeing's Defense, Space & Security division and built in the United Launch Alliance (ULA) facility in Decatur, Alabama. Final assembly is completed at the launch site by ULA. The rockets were designed to launch payloads into orbit for the United States Air Force Evolved Expendable Launch Vehicle (EELV) program and commercial satellite business. Delta IV rockets are available in five versions: Medium, Medium+ (4,2), Medium+ (5,2), Medium+ (5,4), and Heavy, to cover a range of payload size and weight. Delta IV was primarily designed to satisfy the needs of the U.S. military.

The rockets are assembled at the Horizontal Integration Facility for launches from SLC-37B at Cape Canaveral, and in a similar facility for launches from SLC-6 at Vandenberg Air Force Base.

The Delta IV entered the space launch market when global capacity was already much higher than demand. Furthermore, as an unproven design it has had difficulty finding a market in commercial launches, and the cost to launch a Delta IV is higher than that for competing vehicles. In 2003, Boeing pulled the Delta IV from the commercial market, citing low demand and high costs. In 2005, Boeing stated that it sought to return the Delta IV to commercial service.

All of Delta IV's launches, with the exception of its debut launch carrying the Eutelsat W5 commercial communications satellite, were paid for by the US government. In 2015, ULA stated that a Delta IV Heavy is sold for nearly $400 million.

The United States Air Force (USAF) funds Delta IV engineering, integration, and infrastructure through contracts with Boeing Launch Services (BLS). On August 8, 2008 the USAF Space and Missile Systems Center increased the "cost plus award fee" contract with BLS for $1.656 billion to extend the period of performance through the end of FY09^[update]. In addition a $557.1 million option was added to cover FY10.

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Wikipedia