Thor-Delta

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Thor-Delta
Thor Delta with Explorer 10 Mar 25 1961.jpg
Thor-Delta prior to the launch of Explorer 10
Function Expendable launch system
Country of originUnited States
Launch history
StatusRetired
Launch sites Cape Canaveral LC-17
Total launches12
Successes11
Failures1
First flight1960-05-13
Last flight1962-09-18

The Thor-Delta, also known as Delta DM-19 or just Delta was an early American expendable launch system used for 12 orbital launches in the early 1960s. A derivative of the Thor-Able, it was a member of the Thor family of rockets, and the first member of the Delta family. [1]

Expendable launch system Launch system that uses an expendable launch vehicle

An expendable launch system is a launch vehicle that can be launched only once, after which its components are either destroyed during reentry or discarded in space. ELVs typically consist of several rocket stages that are discarded sequentially as their fuel is exhausted and the vehicle gains altitude and speed. Most satellites and human spacecraft are currently launched on ELVs. ELVs are simpler in design than reusable launch systems and therefore may have a lower production cost. Furthermore, an ELV can use its entire fuel supply to accelerate its payload, offering greater fuel efficiency. ELVs are proven technology in wide-use for many decades. ELVs are usable only once, and therefore have a significantly higher per-launch cost than reusable vehicles. New reusable launch systems under development by private companies such as SpaceX and Blue Origin have the potential to obsolete many existing ELVs due to the lower per-launch costs of reusable rockets.

Orbit gravitationally curved path of an object around a point in outer space; circular or elliptical path of one object around another object

In physics, an orbit is the gravitationally curved trajectory of an object, such as the trajectory of a planet around a star or a natural satellite around a planet. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory. To a close approximation, planets and satellites follow elliptic orbits, with the central mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion.

Thor-Able American expendable launch system and sounding rocket used for a series of re-entry vehicle tests and satellite launches between 1958 and 1960

The Thor-Able was an American expendable launch system and sounding rocket used for a series of re-entry vehicle tests and satellite launches between 1958 and 1960. It was a two stage rocket, consisting of a Thor IRBM as a first stage and a Vanguard-derived Able second stage. On some flights, an Altair solid rocket motor was added as a third stage. It was a member of the Thor family and an early predecessor of the Delta.

Contents

The first stage was a Thor missile in the DM-19 configuration. The second stage was the Delta, which had been derived from the earlier Able stage. An Altair solid rocket motor was used as a third stage. [2]

PGM-17 Thor first operational ballistic missile deployed by the U.S. Air Force

The PGM-17A Thor was the first operational ballistic missile of the U.S. Air Force (USAF). 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 (IRBM) with thermonuclear warheads. Thor was 65 feet (20 m) in height and 8 feet (2.4 m) in diameter. It was later augmented in the U.S. IRBM arsenal by the Jupiter.

Able (rocket stage)

The Able rocket stage was a rocket stage manufactured in the United States by Aerojet as the second of three stages of the Vanguard rocket used in the Vanguard project from 1957 to 1959. The rocket engine used nitric acid and UDMH as rocket propellants. The Able rocket stage was discontinued in 1960. The improved Ablestar version was used as the upper stage of the Thor-Ablestar two stage launcher. The Ablestar second stage was an enlarged version of the Able rocket stage, which gave the Thor-Ablestar a greater payload capacity compared to the earlier Thor-Able. It also incorporated restart capabilities, allowing a multiple-burn trajectory to be flown, further increasing payload, or allowing the rocket to reach different orbits. It was the first rocket to be developed with such a capability and development of the stage took a mere eight months.

Altair (rocket stage) Solid-fuel rocket

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 (ABL) as the X-248. It was also sometimes called the Burner 1.

The basic design of the original Vanguard upper stages, featuring a pressure-fed nitric acid/UDMH, regeneratively cooled engine, was kept in place, but with an improved AJ10-118 engine. More significantly, the Delta stage featured cold gas attitude control jets allowing it to be stabilized in orbit for restart and more precise burns.

The Thor-Delta was the first rocket to use the combination of a Thor missile and a Delta upper stage. This configuration was reused for many later rockets, and a derivative, the Delta II, remained in service until 2018.

Delta II American space launch system

Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 variants. The rocket flew its final mission ICESat-2 on 15 September 2018, earning the launch vehicle a streak of 100 successful missions in a row, with the last failure being GPS IIR-1 in 1997.

The Thor-Delta launched a number of significant payloads, including the first communications satellite, Echo 1A; the first British satellite, Ariel 1; and the first active direct-relay communications satellite, Telstar 1. All 12 launches occurred from Cape Canaveral Air Force Station Launch Complex 17. The launch of Telstar 1 used pad B, while all other launches were from pad A. All launches were successful except the maiden flight, which failed to place Echo 1 into orbit due a problem with the second stage.

Communications satellite artificial satellite designed for telecommunications

A communications satellite is an artificial satellite that relays and amplifies radio telecommunications signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. There are 2,134 communications satellites in Earth's orbit, used by both private and government organizations. Many are in geostationary orbit 22,236 miles (35,785 km) above the equator, so that the satellite appears stationary at the same point in the sky, so the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track it.

Ariel 1

Ariel 1, 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 United States. It was constructed in both the UK and the United States by NASA Goddard Space Flight Center and SERC, under an agreement reached as the result of political discussions in 1959 and 1960.

Telstar The name of various communications satellites

Telstar is the name of various communications satellites. The first two Telstar satellites were experimental and nearly identical. Telstar 1 launched on top of a Thor-Delta rocket on July 10, 1962. It successfully relayed through space the first television pictures, telephone calls, and telegraph images, and provided the first live transatlantic television feed. Telstar 2 launched May 7, 1963. Telstar 1 and 2—though no longer functional—still orbit the Earth.

Thor-Delta launches

No.DatePayloadSiteOutcomeRemarks
1May 13, 1960 Echo 1 CCAFS LC 17AFailureLaunch at 9:16 p.m. GMT. Good first stage. Second-stage attitude control system failure. Vehicle destroyed.
2August 12, 1960 Echo 1A CCAFS LC 17ASuccessPayload placed into 1,035 miles (1,666 km), 47 degree inclination orbit.
3November 23, 1960 TIROS-2 CCAFS LC 17ASuccess
4March 25, 1961 Explorer-10CCAFS LC 17ASuccess78 pounds (35 kg) payload placed into elliptical 138,000 miles (222,000 km) orbit.
5July 12, 1961TIROS-3CCAFS LC 17ASuccess
6August 16, 1961Explorer-12CCAFS LC 17ASuccessEnergetic Particle Explorers. EPE-A. [3] Highly elliptical orbit.
7February 8, 1962TIROS-4CCAFS LC 17ASuccess
8March 7, 1962 OSO-1CCAFS LC 17ASuccessOrbiting Solar Observatory. 345 miles (555 km), 33 degree orbit.
9April 26, 1962 Ariel 1 CCAFS LC 17ASuccessAriel 1 was later seriously damaged by the Starfish Prime nuclear test.
10June 19, 1962TIROS-5CCAFS LC 17ASuccess
11July 10, 1962 Telstar 1CCAFS LC 17BSuccessTelstar 1 was later damaged by the Starfish Prime high altitude nuclear event.
12September 18, 1962TIROS-6CCAFS LC 17ASuccess

See also

Delta (rocket family)

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Delta C

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Delta D

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Delta L

The Delta L, Thor-Delta L, or Thrust-Augmented Long Tank Thor-Delta was a US expendable launch system used to launch the Pioneer E and TETR satellites in 1969 (failed) and HEOS satellite in 1972. It was a member of the Delta family of rockets.

Delta M

The Delta M or Thor-Delta M was an American expendable launch system used for thirteen orbital launches between 1968 and 1971. It was a member of the Delta family of rockets.

Delta N

The Delta N or Thor-Delta N was an American expendable launch system used for nine orbital launches between 1968 and 1972. It was a member of the Delta family of rockets, and the last Delta to be given an alphabetical designation - subsequent rockets were designated using a four digit numerical code.

Delta 1000

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Delta 2000

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The Delta 1000, 2000 and 3000 series used surplus NASA Apollo program rockets engines for its first and second stages.

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References

  1. Wade, Mark. "Delta". Encyclopedia Astronautica. Archived from the original on 2013-05-22. Retrieved 2009-02-09.Cite uses deprecated parameter |deadurl= (help)
  2. Krebs, Gunter. "Thor family". Gunter's Space Page. Retrieved 2009-02-09.
  3. "Explorer 12". NASA.