Delta rocket
Overview
 
Delta is a versatile family of expendable launch system
Expendable launch system
An expendable launch system is a launch system that uses an expendable launch vehicle to carry a payload into space. The vehicles used in expendable launch systems are designed to be used only once , and their components are not recovered for re-use after launch...

s that has provided space launch capability in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 since 1960. There have been more than 300 Delta rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

s launched, with a 95 percent success rate. Two Delta launch systems – Delta II
Delta II
Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...

 and Delta IV
Delta IV rocket
Delta IV is an active expendable launch system in the Delta rocket family. Delta IV uses rockets designed by Boeing's Integrated Defense Systems division and built in the United Launch Alliance facility in Decatur, Alabama. Final assembly is completed at the launch site by ULA...

 – are in active use. Delta rockets are currently manufactured and launched by the United Launch Alliance
United Launch Alliance
United Launch Alliance is a joint venture of Lockheed Martin and Boeing. ULA was formed in December 2006 by combining the teams at these companies which provide spacecraft launch services to the government of the United States. U.S...

.
The original Delta rockets used a modified version of the PGM-17 Thor
PGM-17 Thor
Thor was the first operational ballistic missile of the U.S. Air Force . Named after the Norse god of thunder, it was deployed in the United Kingdom between 1959 and September 1963 as an intermediate range ballistic missile with thermonuclear warheads. Thor was in height and in diameter. It was...

, the first ballistic missile
Ballistic missile
A ballistic missile is a missile that follows a sub-orbital ballistic flightpath with the objective of delivering one or more warheads to a predetermined target. The missile is only guided during the relatively brief initial powered phase of flight and its course is subsequently governed by the...

 deployed by the United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

, as their first stage
Multistage rocket
A multistage rocket is a rocket that usestwo or more stages, each of which contains its own engines and propellant. A tandem or serial stage is mounted on top of another stage; a parallel stage is attached alongside another stage. The result is effectively two or more rockets stacked on top of or...

.
Encyclopedia
Delta is a versatile family of expendable launch system
Expendable launch system
An expendable launch system is a launch system that uses an expendable launch vehicle to carry a payload into space. The vehicles used in expendable launch systems are designed to be used only once , and their components are not recovered for re-use after launch...

s that has provided space launch capability in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 since 1960. There have been more than 300 Delta rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

s launched, with a 95 percent success rate. Two Delta launch systems – Delta II
Delta II
Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...

 and Delta IV
Delta IV rocket
Delta IV is an active expendable launch system in the Delta rocket family. Delta IV uses rockets designed by Boeing's Integrated Defense Systems division and built in the United Launch Alliance facility in Decatur, Alabama. Final assembly is completed at the launch site by ULA...

 – are in active use. Delta rockets are currently manufactured and launched by the United Launch Alliance
United Launch Alliance
United Launch Alliance is a joint venture of Lockheed Martin and Boeing. ULA was formed in December 2006 by combining the teams at these companies which provide spacecraft launch services to the government of the United States. U.S...

.

Delta origins

The original Delta rockets used a modified version of the PGM-17 Thor
PGM-17 Thor
Thor was the first operational ballistic missile of the U.S. Air Force . Named after the Norse god of thunder, it was deployed in the United Kingdom between 1959 and September 1963 as an intermediate range ballistic missile with thermonuclear warheads. Thor was in height and in diameter. It was...

, the first ballistic missile
Ballistic missile
A ballistic missile is a missile that follows a sub-orbital ballistic flightpath with the objective of delivering one or more warheads to a predetermined target. The missile is only guided during the relatively brief initial powered phase of flight and its course is subsequently governed by the...

 deployed by the United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

, as their first stage
Multistage rocket
A multistage rocket is a rocket that usestwo or more stages, each of which contains its own engines and propellant. A tandem or serial stage is mounted on top of another stage; a parallel stage is attached alongside another stage. The result is effectively two or more rockets stacked on top of or...

. The Thor had been designed in the mid-1950s to reach Moscow from bases in Britain or similar allied nations, and the first wholly successful Thor launch had occurred in September 1957. Subsequent satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 and space probe
Space probe
A robotic spacecraft is a spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to...

 flights soon followed, using a Thor first stage with several different upper stages. The fourth upper stage used on the Thor was the Thor "Delta," delta being the fourth letter of the Greek alphabet. Eventually the entire Thor-Delta launch vehicle came to be called simply, "Delta."

NASA intended Delta as "an interim general purpose vehicle" to be "used for communication, meteorological, and scientific satellites and lunar probes during '60 and '61". The plan was to replace Delta with other rocket designs when they came on-line. The Delta design emphasized reliability rather than performance by replacing components which had caused problems on earlier Thor flights. NASA let the original Delta contract to the Douglas Aircraft Company
Douglas Aircraft Company
The Douglas Aircraft Company was an American aerospace manufacturer, based in Long Beach, California. It was founded in 1921 by Donald Wills Douglas, Sr. and later merged with McDonnell Aircraft in 1967 to form McDonnell Douglas...

 in April 1959 for 12 vehicles of this design:
  • Stage 1: Modified Thor IRBM with a Block I MB-3 engine producing 152000 lbf (676.1 kN) thrust. (LOX/RP1 turbopump, gimbal mounted engine, two verniers for roll control)
  • Stage 2: Modified Able. Pressure fed UDMH/nitric acid powered Aerojet
    Aerojet
    Aerojet is an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California with divisions in Redmond, Washington, Orange, Gainesville and Camden, Arkansas. Aerojet is owned by GenCorp. They are the only US propulsion company that provides both solid rocket...

     AJ-10-118 engine producing 7700 lbf (34.3 kN). This reliable engine cost $4 million to build and is still flying in modified form today. Gas jet attitude control system.
  • Stage 3: Altair
    Altair (rocket stage)
    The Altair was a solid-fuel rocket with a fiberglass casing, initially developed for use as the third stage of Vanguard rockets. It was manufactured by Allegany Ballistics Laboratory as the X-248. It was also sometimes called the Burner 1.-Uses:...

    . A spin stabilized (via a turntable on top of the Able) at 100 rpm by two solid rocket motors before separation. One ABL X-248 solid rocket motor provided 2800 lbf (12.5 kN) of thrust for 28 seconds. The stage weighed 500 pounds (226.8 kg) and was largely constructed of wound fiberglass.


These vehicles would be able to place 650 pounds (294.8 kg) into a 150 to 230 mi (241.4 to 370.1 km) LEO
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

 or 100 pounds (45.4 kg) into GTO
Geostationary transfer orbit
A geosynchronous transfer orbit or geostationary transfer orbit is a Hohmann transfer orbit used to reach geosynchronous or geostationary orbit....

. Eleven of the twelve initial Delta flights were successful. The total project development and launch cost came to $43 million, $3 million over budget. An order for 14 more vehicles was let before 1962.

Early Delta flights

No. Date Payload Site Outcome Remarks
1 May 13, 1960 Echo 1
Echo satellite
Project Echo was the first passive communications satellite experiment. Each of the two American spacecraft was a metalized balloon satellite acting as a passive reflector of microwave signals. Communication signals were bounced off of them from one point on Earth to another.-Echo 1:NASA's Echo 1...

CCAFS
Cape Canaveral Air Force Station
Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...

 LC 17
Cape Canaveral Air Force Station Launch Complex 17
Cape Canaveral Air Force Station Space Launch Complex 17 , previously designated Launch Complex 17 , was a launch site at Cape Canaveral Air Force Station, Florida used for Thor and Delta rocket launches between 1958 and 2011....

A
failure Launch at 9:16 p.m. GMT. Good first stage. Second stage attitude control system failure. Vehicle destroyed.
2 August 12, 1960 Echo 1A
Echo satellite
Project Echo was the first passive communications satellite experiment. Each of the two American spacecraft was a metalized balloon satellite acting as a passive reflector of microwave signals. Communication signals were bounced off of them from one point on Earth to another.-Echo 1:NASA's Echo 1...

success Payload placed into 1035 miles (1,665.7 km), 47 degree inclination orbit.
3 TIROS
TIROS
TIROS, or Television Infrared Observation Satellite, is a series of early weather satellites launched by NASA, beginning with TIROS-1 in 1960. TIROS was the first satellite that was capable of remote sensing of the Earth. This initial remote-sensing effort was significant because it enabled Earth...

-2
success
4 March 25, 1961 Explorer
Explorer program
The Explorer program is a United States space exploration program that provides flight opportunities for physics, heliophysics, and astrophysics investigations from space. Over 90 space missions have been launched from 1958 to 2011, and it is still active...

-10
success 78 pounds (35.4 kg) payload placed into elliptical 138000 miles (222,088.9 km) orbit.
5 July 12, 1961 TIROS-3 success
6 August 16, 1961 Explorer-12 success Energetic Particle Explorers. EPE-A. Highly elliptical orbit.
7 February 8, 1962 TIROS-4 success
8 March 7, 1962 OSO
Orbiting Solar Observatory
The Orbiting Solar Observatory Program was the name of a series of nine American science satellites primarily intended to study the Sun, though they also included important non-solar experiments. Eight were launched successfully by NASA between 1962 and 1975 using Delta rockets...

-1
success Orbiting Solar Observatory. 345 miles (555.2 km), 33 degree orbit.
9 April 26, 1962 Ariel 1
Ariel 1
Ariel 1, also known as UK-1 and S-55, was the first British satellite, and the first satellite in the Ariel programme. Its launch in 1962 made the United Kingdom the third country to operate a satellite, after the Soviet Union and the USA...

success Ariel 1 was later seriously damaged by the Starfish Prime
Starfish Prime
Starfish Prime was a high-altitude nuclear test conducted by the United States of America on July 9, 1962, a joint effort of the Atomic Energy Commission and the Defense Atomic Support Agency ....

 nuclear test.
10 June 19, 1962 TIROS-5 success
11 July 10, 1962 Telstar
Telstar
Telstar is the name of various communications satellites, including the first such satellite to relay television signals.The first two Telstar satellites were experimental and nearly identical. Telstar 1 was launched on top of a Thor-Delta rocket on July 10, 1962...

 1
success Also later damaged by the Starfish Prime high altitude nuclear event.
12 September 18, 1962 TIROS-6 success


Delta evolution

Delta A

Block II MB-3 engine, 170000 lbf (756.2 kN) vs. 152000 lbf (676.1 kN)

13. EPE2

14. EPE3

Delta B

  • Upgraded AJ10-118D upper stage—3-foot tank stretch, higher energy oxidizer, solid-state guidance system
  • Delta program goes from 'interim' to 'operational' status. to GTO


15. 13 December 1962. Relay 1, second NASA communications satellite, NASA's first active one

16. 13 February 1963. pad 17b. Syncom 1; Thiokol Star 13B solid rocket as apogee kick motor

20. July 26, 1963. Syncom
Syncom
Syncom started as a 1961 NASA program for active geosynchronous communication satellites, all of which were developed and manufactured by Hughes Space and Communications...

 2; geosynchronous orbit, but inclined 33° due to the limited performance of the Delta

Delta C

  • Third stage Altair replaced with Altair 2—its engine having been developed as the ABL X-258 for the Scout vehicle; 3 in (76.2 mm) longer, 10% heavier, but 65% more total thrust
Sample mission: OSO-4

Delta D

  • Also known as Thrust Augmented Delta
  • A Delta C with the Thrust Augmented Thor core plus three Castor 1 boosters


25. 19 August 1964. Syncom
Syncom
Syncom started as a 1961 NASA program for active geosynchronous communication satellites, all of which were developed and manufactured by Hughes Space and Communications...

 3, the first geostationary
Geostationary orbit
A geostationary orbit is a geosynchronous orbit directly above the Earth's equator , with a period equal to the Earth's rotational period and an orbital eccentricity of approximately zero. An object in a geostationary orbit appears motionless, at a fixed position in the sky, to ground observers...

 communications satellite

30. 6 April 1965. Intelsat I
Intelsat I
Intelsat I was the first communications satellite to be placed in geosynchronous orbit, on April 6, 1965...


Delta E

  • Also known as Thrust Augmented Improved Delta
  • 1965 more to GTO than Delta D
  • Castor 2
    Castor (rocket stage)
    The Castor family of solid-fuel rocket stages and boosters were built by Thiokol and used on a variety of launch vehicles. They were initially developed as the second stage motor of the Scout rocket...

     vs. Castor 1 boosters; Same thrust, longer duration
  • MB-3 Block III core engine, 2000 lbf (8.9 kN) more thrust
  • AJ10-118E second stage widened from 2.75 foot (0.8382 m) to 4.58 feet (1.4 m) diameter; Double burn time
  • Additional helium tanks allow for almost unlimited restarts.
  • Two available third stages: Altair 2 or FW-4D; the latter caused the Delta to be known as a Delta E1
  • New payload fairing from Agena


First Delta E. 6 November 1965; Launched GEOS 1

Delta G

  • Two stage Delta Es.
  • used for Biosatellite 1 and 2 flights


1. 14 December 1966. Biosatellite 1

2. 7 September 1967. Biosatellite 2

Delta L

  • Introduced Extended Long Tank first stage- 8 feet (2.4 m) diameter throughout
  • FW-4d motor for third stage

Delta N

  • Two stage version of Delta M.
  • There were nine Delta N launch attempts from 1968 until 1972; eight were successful.

'Super Six'

  • Delta M or Delta N with three extra strap-ons to GTO
    Geostationary transfer orbit
    A geosynchronous transfer orbit or geostationary transfer orbit is a Hohmann transfer orbit used to reach geosynchronous or geostationary orbit....


Launch reliability

From 1969 through 1978 (inclusive), Thor-Delta was NASA's most popular launcher, with 84 launch attempts. (Scout
Scout (rocket)
The Scout family of rockets were launch vehicles designed to place small satellites into orbit around the Earth. The Scout multistage rocket was the first orbital launch vehicle to be entirely composed of solid fuel stages....

 was the second-most used vehicle with 32 launches.)
NASA used it to launch its own satellites, and also to launch satellites for other government agencies and foreign governments on a cost-reimbursable basis. Sixty-three of the satellites NASA attempted to launch were provided by other parties. Out of the 84 attempts there were seven failures or partial failures (91.6% successful).

Delta numbering system

In 1972, McDonnell Douglas
McDonnell Douglas
McDonnell Douglas was a major American aerospace manufacturer and defense contractor, producing a number of famous commercial and military aircraft. It formed from a merger of McDonnell Aircraft and Douglas Aircraft in 1967. McDonnell Douglas was based at Lambert-St. Louis International Airport...

 introduced a four-digit numbering system to replace the letter-naming system. The new system could better accommodate the various changes and improvements to Delta rockets (and avoided the problem of a rapidly depleting alphabet). It specified (1) the tank and main engine type, (2) number of solid boosters, (3) second stage, and (4) third stage.
Number First Digit
(First stage/boosters)
Second Digit
(Number of boosters)
Third Digit
(Second Stage)
Fourth Digit
(Third stage)
Letter
(Heavy configuration)
0 Long Tank Thor
MB-3 engine
Castor
Castor (rocket stage)
The Castor family of solid-fuel rocket stages and boosters were built by Thiokol and used on a variety of launch vehicles. They were initially developed as the second stage motor of the Scout rocket...

 2 SRBs
No SRBs Delta, with AJ-10 engines No third stage N/A
1 Extended Long Tank Thor
MB-3 engine
Castor 2 SRBs
N/A Delta, with TR-201 engines N/A
2 Extended Long Tank Thor
RS-27 engine
Castor 2 SRBs
2 SRBs (or LRBs in the case of the Delta IVH) Delta K, with AJ-10 engines FW-4D (unflown)
3 Extended Long Tank Thor
RS-27 engine
Castor
Castor (rocket stage)
The Castor family of solid-fuel rocket stages and boosters were built by Thiokol and used on a variety of launch vehicles. They were initially developed as the second stage motor of the Scout rocket...

 4 SRBs
3 SRBs Delta III cryogenic upper stage, RL-10B-2
RL-10
The RL10 was USA's first liquid hydrogen fueled rocket engine. An updated version is used in several current launch vehicles. Six RL10 engines were used in the S-IV second stage of the Saturn I rocket. One or two RL10 engines are used in the Centaur upper stages of Atlas and Titan rockets...

 engine
Star 37D
4 Extended Long Tank Thor
MB-3 engine
Castor 4A SRBs
4 SRBs Delta IV 4m diameter cryogenic upper stage, RL-10B-2
RL-10
The RL10 was USA's first liquid hydrogen fueled rocket engine. An updated version is used in several current launch vehicles. Six RL10 engines were used in the S-IV second stage of the Saturn I rocket. One or two RL10 engines are used in the Centaur upper stages of Atlas and Titan rockets...

 engine
Star 37E
5 Extended Long Tank Thor
RS-27 engine
Castor 4A SRBs
N/A Delta IV 5m diameter cryogenic upper stage, RL-10B-2
RL-10
The RL10 was USA's first liquid hydrogen fueled rocket engine. An updated version is used in several current launch vehicles. Six RL10 engines were used in the S-IV second stage of the Saturn I rocket. One or two RL10 engines are used in the Centaur upper stages of Atlas and Titan rockets...

 engine
Star 48B/PAM-D
6 Extra-Extended Long Tank Thor
RS-27 engine
Castor 4A SRBs
6 SRBs N/A Star 37FM
7 Extra-Extended Long Tank Thor
RS-27A engine
GEM 40 SRBs
N/A N/A GEM 46 SRBs
8 Strengthened Extra-Extended Long Tank Thor
RS-27A engine
GEM 46 SRBs
N/A
9 Delta IV CBC
RS-68 engine
9 SRBs 2 additional CBC Parallel first stages

This numbering system was to have been phased out in favor of a new system that was introduced in 2005. In practice, this system was never been used.
Number First Digit
(First stage/boosters)
Second Digit
(Number of boosters)
Third Digit
(Second Stage)
Fourth Digit
(Third stage)
Letter
(Heavy configuration)
0 N/A No SRBs N/A No third stage N/A
1 N/A N/A
2 Extra-Extended Long Tank Thor
RS-27A engine
GEM 40 SRBs
2 SRBs (or LRBs in the case of the Delta IVH) Delta K, with AJ-10 engines GEM 46 SRBs
3 Strengthened Extra-Extended Long Tank Thor
RS-27A engine
GEM 46 SRBs
3 SRBs N/A
4 Delta IV CBC
RS-68 engine
4 SRBs Delta IV 4m diameter cryogenic upper stage, RL-10B-2
RL-10
The RL10 was USA's first liquid hydrogen fueled rocket engine. An updated version is used in several current launch vehicles. Six RL10 engines were used in the S-IV second stage of the Saturn I rocket. One or two RL10 engines are used in the Centaur upper stages of Atlas and Titan rockets...

 engine
2 additional CBC Parallel first stages
5 N/A N/A Delta IV 5m diameter cryogenic upper stage, RL-10B-2
RL-10
The RL10 was USA's first liquid hydrogen fueled rocket engine. An updated version is used in several current launch vehicles. Six RL10 engines were used in the S-IV second stage of the Saturn I rocket. One or two RL10 engines are used in the Centaur upper stages of Atlas and Titan rockets...

 engine
Star 48B/PAM-D N/A
6 N/A Star 37FM
7 N/A
8
9 9 SRBs

Delta 904

On July 23, 1972, the launch of Landsat 1
Landsat 1
Landsat 1, originally named "Earth Resources Technology Satellite 1", was the first satellite of the United States' Landsat program. It was a modified version of the Nimbus 4 meteorological satellite and was launched on July 23, 1972 by a Delta 900 rocket from Vandenberg Air Force Base in California...

 marked the first use of nine strap-on boosters, and the new uprated second-stage engine (AJ 10-118F). This Thor-Delta model was designated the 904.

Delta 1000-Series

  • Extended Long Tank with 8 feet (2.4 m) payload fairing; nicknamed "Straight-Eight".
  • Nine Castor II strap-on solid boosters.
  • The first successful 1000 series Thor-Delta launched Explorer 47
    Explorer program
    The Explorer program is a United States space exploration program that provides flight opportunities for physics, heliophysics, and astrophysics investigations from space. Over 90 space missions have been launched from 1958 to 2011, and it is still active...

     on September 22, 1972.

Delta 2000-Series

  • Features new Rocketdyne
    Rocketdyne
    Rocketdyne was a Rocket engine design and production company headquartered in Canoga Park, California, United States. The company was related to North American Aviation for most of its history. NAA merged with Rockwell International, which was then bought by Boeing in December, 1996...

     RS-27 main engine on Extended Long Tank. Same constant eight-foot diameter.
  • Delta 2910 boosters were used to launch both Landsat 2
    Landsat 2
    Landsat 2 is the second satellite of the Landsat program. The spacecraft originally carried a designation of ERTS-B but was renamed "Landsat 2" prior to its launch on January 22, 1975...

     in 1975 and Landsat 3
    Landsat 3
    Landsat 3 is the third satellite of the Landsat program. It was launched on March 5, 1978, with the primary goal of providing a global archive of satellite imagery...

     in 1978.
  • A Delta 2914 was used 1978-04-07 to launch the Japanese BSE Broadcasting Satellite, also known as "Yuri 1".

Delta 3000-Series

  • Introduced upgraded Castor IV solid motors. Same first stage as 1000- and 2000-series.
  • Also introduced PAM (Payload Assist Module)/Star 48B solid-fueled kick motor. Later used as Delta II third stage.
  • The Delta 3914 model was approved for launching U.S. government payloads in May 1976.

Delta 4000-Series

  • Used old MB-3 main engine on Extended Long Tank with Castor IV motors.
  • Only launched two missions.
  • First use of a Delta-K second stage.

Delta 5000-Series

  • Featured upgraded Castor IVA motors on Extended Long Tank first stage with RS-27 main engine.
  • Only launched one mission.

Delta II series

The Delta II series consists of the retired Delta 6000, the active Delta 7000, and two variants (Lite and Heavy) of the latter.

Delta 6000-Series

When in 1986 the Challenger accident
Space Shuttle Challenger disaster
The Space Shuttle Challenger disaster occurred on January 28, 1986, when Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the deaths of its seven crew members. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida at 11:38 am EST...

 demonstrated that Delta launches would continue, the Delta II
Delta II
Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...

 was developed.
  • Introduced Extra Extended Long Tank first stage. 12 additional feet provide more propellant.
  • Introduced Castor
    Castor (rocket stage)
    The Castor family of solid-fuel rocket stages and boosters were built by Thiokol and used on a variety of launch vehicles. They were initially developed as the second stage motor of the Scout rocket...

     IVA boosters. Six ignite at takeoff, three ignite in flight.

Delta 7000-Series

  • Introduces RS-27A main engine, modified for efficiency at high altitude, at some cost to low-altitude performance.
  • Introduces GEM-40 (Graphite-Epoxy Motor
    Graphite-Epoxy Motor
    A Graphite-Epoxy Motor is a high-performance, solid rocket motor, used for supplemental thrust on several launch vehicles, including the Boeing Delta II and Delta IV. They are designed to allow launch vehicles to deliver larger payloads to orbit...

    ) solid boosters from Hercules
    Hercules Inc.
    Hercules, Inc., was a chemical and munitions manufacturing company based in Wilmington, Delaware, which was formed in 1912 as the Hercules Powder Company. Hercules was spun-off from the DuPont Corporation as a result of U.S. federal government actions in the field of antitrusts...

     (now Alliant
    Alliant Techsystems
    Alliant Techsystems Inc., most commonly known by its ticker symbol, ', is one of the largest aerospace and defense companies in the United States with more than 18,000 employees in 22 states, Puerto Rico and internationally, and 2010 revenues in excess of an estimated...

    ). Besides being longer, their lighter casings allow higher payload capability.

Delta II Med-Lite

A 7000-series with no third stage and fewer strap-ons (often three, sometimes four). Usually used for small NASA missions.

Delta III (8000-Series)

A McDonnell Douglas/Boeing-developed program to keep pace with growing satellite masses:
  • The two upper stages, with low-performance fuels, were replaced with a single cryogenic stage, improving performance and reducing recurring costs and pad labor. Engine was a single Pratt & Whitney RL10, from the Centaur upper stage. The hydrogen fuel tank, 4 meters in diameter in orange insulation, is exposed; the narrower oxygen tank and engine are covered until stage ignition. Fuel tank contracted to Mitsubishi, and produced using technologies from Japanese H-II
    H-II
    The H-II rocket was a Japanese satellite launch system, which flew seven times between 1994 and 1999, with five successes. It was developed by NASDA in order to give Japan a capability to launch larger satellites in the 1990s. It was the first two-stage liquid-fuelled rocket Japan made using only...

     launcher.
  • To keep the stack short and resistant to crosswinds, the first-stage kerosene tank was widened and shortened, matching the upper-stage and fairing diameters.
  • Nine enlarged GEM-46 solid boosters attached. Three have thrust-vectoring
    Thrust vectoring
    Thrust vectoring, also thrust vector control or TVC, is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine or motor in order to control the attitude or angular velocity of the vehicle....

     nozzles.


Of the three Delta III flights, the first two were failures and the third carried only a dummy (inert) payload.

Delta IV (9000-series)

As part of the Air Force's EELV (Evolved Expendable Launch Vehicle) program, McDonnell Douglas/Boeing proposed Delta IV. As the program implies, many components and technologies were borrowed from existing launchers. Both Boeing and Lockheed Martin
Lockheed Martin
Lockheed Martin is an American global aerospace, defense, security, and advanced technology company with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It is headquartered in Bethesda, Maryland, in the Washington Metropolitan Area....

 were contracted to produce their EELV designs. Delta IVs are produced in a new facility in Decatur, Alabama
Decatur, Alabama
Decatur is a city in Limestone and Morgan Counties in the U.S. state of Alabama. The city, affectionately known as "The River City", is located in Northern Alabama on the banks of Wheeler Lake, along the Tennessee River. It is the largest city and county seat of Morgan County...

.
  • First stage changed to liquid hydrogen fuel. Tank technologies derived from Delta III upper stage, but widened to 5 meters.
  • Kerosene engine replaced with Rocketdyne RS-68, the first new, large liquid-fueled rocket engine designed in the US since the Space Shuttle Main Engine
    Space Shuttle main engine
    The RS-25, otherwise known as the Space Shuttle Main Engine , is a reusable liquid-fuel rocket engine built by Pratt & Whitney Rocketdyne for the Space Shuttle, running on liquid hydrogen and oxygen. Each Space Shuttle was propelled by three SSMEs mated to one powerhead...

     (SSME) in the '70s. Designed for low cost; has lower chamber pressure and efficiency than the SSME, and a much simpler nozzle. Thrust chamber and upper nozzle is a channel-wall design, pioneered by Soviet engines. Lower nozzle is ablatively cooled.
  • Second stage and fairing taken from the Delta III in smaller (Delta IV Medium) models; widened to 5 meters in Medium+ and Heavy models.
  • Medium+ models have two or four GEM-60 60-inch diameter solid boosters.
  • Revised plumbing and electric circuits eliminate need for a launch tower.


The first stage is referred to as a common booster core (CBC); a Delta IV Heavy attaches two extra CBCs as boosters.

Future development

Currently development is focused on the Delta IV Heavy, which uses three Common Booster Cores to lift higher masses to orbit and escape velocity
Escape velocity
In physics, escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero gravitational potential energy is negative since gravity is an attractive force and the potential is defined to be zero at infinity...

.

See also

  • List of Thor and Delta launches
  • HoloVID
    HoloVID
    HoloVID is a tool originally developed for the holographic dimensional measurement of the internal isogrid webbing of the Delta Series of Space Craft skins by Mark Slater in 1981.-History:...

  • Contribution to space debris
    Space debris
    Space debris, also known as orbital debris, space junk, and space waste, is the collection of objects in orbit around Earth that were created by humans but no longer serve any useful purpose. These objects consist of everything from spent rocket stages and defunct satellites to erosion, explosion...

  • Echo 1
  • Project Echo

External links

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