Atlas (rocket family)
The Atlas, once developed as intercontinental ballistic missile is a launcher that was used primarily in the 1960s, the Mercury and Gemini programs. Further developments of the Atlas rocket are still as launchers for satellites and space probes in use.
- 2.1 Specifications
History
ICBM
The development of the Atlas began in March 1946, when the company Consolidated Vultee Aircraft Corporation was commissioned to build an intercontinental ballistic missile with a range of 8000 km ( project MX -774 or hiroc ). The project was completed but after a short time due to lack of money, but in 1951 revived the face of Soviet armament (as project MX- 1593 or Atlas ). The first launch of an Atlas took place on 11 June 1957. However, due to a fault in the fuel system, the rocket had to be destroyed after the start of 51 seconds. Thus, the first successful flight of an intercontinental ballistic missile of the Soviet Union were reserved.
The U.S. Air Force but moved in the same year, on 17 December 1957 with the first successful flight of the Atlas A to. A year later graduated from the Atlas B on November 29, 1958 the first flight over the full distance. In the same year it was decided to use the Atlas as a launch vehicle for the Mercury program. In September 1959, the first Atlas D took up the troops service. In May 1960, the Atlas D put on the valid to date record for the longest known flight of an intercontinental ballistic missile with a flight distance of almost 14,500 kilometers. Due to their high reaction time, the atlas was found in 1965 out of service. It was replaced by the more appropriate military ICBMs Minuteman and Titan II. Decommissioned Atlas intercontinental ballistic missiles of the type were used until the 1990s as launchers for small payloads.
Models:
- Atlas A: development model with only two engines, low fuel charge, a very simple control system and missile tip dummy
- Atlas B: development model with drive close to the later service configuration and detachable tip; the 10 rocket this series introduced the first communications satellite into orbit Score
- Atlas D ( Atlas LV -3B ): first use model with radio - inertial guidance; First flight April 1959; first barracks Vandenberg Air Force Base from September 1959 horizontally in bunkers; Warhead W - 49 Mk.2 / 3 zip (1.44 MT); retired in 1965; Use for Mercury program at NASA
- Atlas E: use model with inertial control, improved refueling system and improved drive; Deployment from 1961 horizontally in bunkers; W -47 warhead in Mk.4 RV (3.75 MT); retired in 1965, used until 1995 with one or more solid upper stages as a launcher
- Atlas F: much improved model, stationed in silos since 1962; W -47 warhead in Mk.4 RV (3.75 MT); retired in 1965; used until 1981 with one or more solid upper stages as a launcher
Space - carrier system 1st generation
After the first start a converted Atlas -B as a satellite carrier is trying to exploit the ability of the Atlas rocket for heavier payloads. These were equipped with the Atlas -C from an Able upper stage and Altair - third each stage of the Vanguard rocket and tried this combination with a 175 kg mass spacecraft into a transfer orbit to get to the moon. From this known as Atlas -Able version only four were built, three of which were launched between November 15, 1959, and December 15, 1960. All three missiles failed, the fourth was not even started because they already exploded during a test on the launch pad.
For the Mercury program decommissioned Atlas -D were used. The first launch of such a Mercury Atlas rocket took place on July 29, 1960, but failed. After almost one and a half years and another test launch of the Monkey Enos was born on November 29, 1961 successfully with the Mercury Atlas 5 is brought into orbit and thus successfully passed the dress rehearsal for the first manned flight. This graduated from John Glenn on February 20, 1962 as part of the Mercury 6 mission, becoming the first American in orbit. The three subsequent Mercury missions were carried out with an Atlas rocket.
The Atlas Agena upper stage launched since 1960, numerous military and NASA payloads. Also in the Gemini program, the Atlas - Agena Agena upper stage carried her into orbit, which served the manned Gemini spacecraft as a docking target there. From this version, there were six variants (Atlas LV -3A Agena A, Atlas LV -3A Agena B, Atlas LV -3 Agena D, Atlas SLV -3 Agena D and Atlas SLV -3A Agena D) which is used in the base - and advanced distinguished.
At the same time, as the Atlas - Agena A was developed by the USAF, NASA had a development program for a Atlas -Vega with higher power for launching satellites and space probes. The Atlas -Vega would have three stages for the start of higher circulation and escape paths. In -offs in low-Earth orbits, only the first two stages should be used. The second stage should obtain a modified General Electric engine of the Vanguard first stage. The third stage, called Vega, was developed by JPL. The development of the Atlas -Vega has been set, as the USAF developed the same powerful Atlas - Agena -B. The Atlas -Vega was never used.
First stage of the Atlas -Vega without booster
The second stage of the Atlas -Vega
Vega upper with payload in the payload fairing
The Atlas rocket was used in conjunction with the Centaur upper stage to launch its Surveyor lunar probes, Mariner 9, Pioneer Venus, Pioneer 10 and 11. In addition, this called as Atlas - Centaur LV -3C version launched commercial and military communications satellites in the Geotransferorbit. Also from this rocket, there were several versions. In the original version LV -3C an Atlas D came with a Centaur upper stage C - employed. Later versions of the Atlas SLV -3C Centaur D, Atlas SLV -3C Centaur D1A and Atlas Centaur SLV -3C D1AR followed, where the start and later on some start even earlier versions of the Centaur or additional kick stages were used in tests.
Notably, the military also an Atlas rocket was used with a smaller solid propellant upper stage. This brought NOAA weather satellites and military payloads from Vandenberg AFB into a polar orbit.
Space - carrier system 2nd generation
In the 1980s, the Atlas could not keep up with the increased payload requirements, with her at the same time made the Ariane and the Delta rocket competition. So it was decided to base the Atlas Centaur D- 1AR to a strengthening of the base level, which was extended by three meters and thus 17 t could hold more fuel. This referred to as Atlas G Centaur version launched on 9 June 1984 on its maiden flight, the payload Intelsat V F-9 due to an error in the Centaur upper stage did not reach its orbit and burned up a few months later. Overall, this version was used until 1989, seven times. Based on this rocket also used five times for the start of military radio reconnaissance satellites Atlas H, which consisted of the base level of the Atlas G without the Centaur upper stage was built.
When, after the Challenger disaster became clear that an unmanned vehicle system to start communication satellites and medium military payloads were needed ( Titan IV took over the heavy, Delta II, the lighter payloads ), 1990, largely based on the Atlas G Atlas I was introduced. Simultaneously, the risk of developing the NASA has been transferred to the private manufacturer. From now on, the development of the missile was no longer funded by NASA, but was indirectly subsidized by the Book of several missiles to developing type by NASA and the Department of Defense. Major change from the Atlas G was the equipment with digital instead of analog control systems. The first starts out of eleven on 25 July 1990, the last on 25 April 1997. During the three false starts was twice the turbopump of the Centaur upper stage, and even blame a loss in capacity of the base level.
A year later, the heavily revised, larger and slightly stronger Atlas II It had improved engines in the first stage, structural reinforcements and some simplifications in the structure, which greatly improved the reliability of the rocket. This was followed by the commercial version of Atlas IIA, which used an improved Centaur stage and the Atlas IIAS, which also has decreed four Castor IVA solid rocket boosters to help launch and so the payload to 8.6 t ( LEO ) or 3.63 t (GTO ) increased. The Atlas II flew in the years 1991-2004 63 inserts that ran all successful.
The initially planned as a development of the Atlas II Atlas III (formerly known as Atlas IIAR ) was to develop after the decision, the Atlas V, as an interim solution to the Atlas V viewed. You should test a large portion of new technologies that should be used in the later Atlas V. The Atlas IIIA used as the first American rocket, a Russian RD -180 main engine, which was derived from the engine of the Zenit rocket. Due to the much higher thrust of the RD -180 rocket could be severe, to the tanks have been significantly extended to accommodate more fuel. However, the controllable engine startup worked despite the higher weight only at 74 % of its full capacity, since otherwise the structure of the missile would be overloaded with the meantime and acceleration values are achieved through 5g. On 24 May 2000 launched the first Atlas IIIA, on 21 February 2002, the first Atlas IIIB. The Centaur, the Atlas III was designed so that they could be driven with either a (IIIA ) or two ( IIIB) RL -10 engines and accordingly shorter or longer tank ( SEC = Single Engine Centaur, DEC = Dual Engine Centaur ). This technique is also used in the Atlas V for use. Since the Atlas III only a temporary solution was to their production was discontinued after the launch of the Atlas V. She graduated between May 2000 and February 2005, only six starts (two IIIA and IIIB four ), all of which were successful.
All Atlas rockets of the second generations were equipped with Centaur upper stages. Since the stage was default to the rocket, their use was no longer as in the Atlas - Centaur of the first generation specially marked.
Development
As a further development, the Atlas V, in 2002 its maiden flight, and is described due to the large differences in a separate article was written. An Atlas IV did not exist, probably this number was skipped, not to be confused with the Titan IV, which also comes from the same manufacturer.
Technology
The Atlas of the first generation weighed in at a height of 29.1 meters about 116 tons and was able to carry a payload of 1.4 tons. It was fabricated in a 1.5 -stage construction and consisted of a main building and two additional start engines, the latter were dropped after about 130 s, while the main engine continued to work. This unusual, developed in the 1950s was followed by gradual approach from the fear that a rocket engine could in the vacuum of space may not be reliably ignited. Therefore we chose a concept in which all three engines ignite on the ground. All engines were powered from the same tank. Silvery outer skin consisting of stainless steel and had to be stiffened by internal pressure due to its only a millimeter thick wall when transported empty on the earth. The fuel is in the fuselage, i.e., not in two separate tanks, but in a tank with an insulated intermediate floor transported. This design enables the Atlas was characterized by an extremely low curb weight. The main engine was already ignited at the start and burned a total of 402 seconds, which was supported at the beginning for 131 seconds from the start both engines. The fuel consisted of kerosene, which was at a pressure of 4.2 bar, and oxygen, which was compressed to 2.1 bar. The Atlas was made by Convair, the three engines were increased with time in performance. From the Atlas III, however, they switched to a Russian engine with two combustion chambers and significantly higher specific impulse and thrust.