Ariane 4

The Ariane 4 is a European carrier rocket from the Ariane series, which was developed under ESA contract. With 116 starts, of which 113 were successful, it is the most successful Arianemodell with a reliability of 97.4 %. Your first flight she had on 15 June 1988.

The Ariane 4 rockets were between 55 m and 60 m high and could carry a payload of up to 4.9 tons into geostationary transfer orbit transport. The initial weight was between 243 t and 480 t. Ariane 4 usually transported two superposed satellite into orbit. This feature helped the Ariane 4 from low starting price and with high reliability Arianespace to a strong dominance in satellite transport business. Arianespace held so for several years a world market share of about 60%. On 15 February 2003 Flight 159, the last launch of an Ariane 4 rocket.

Only after the last launch of the Ariane 4 people realized that they are covering a capacity gap at the start moderate communication satellites, which was now open. Therefore start in place since the end of 2010, the Soyuz at Kourou.

Technical Features

The Ariane 4 is based on the third Ariane rocket in order to adapt to the different heavy payloads and could withstand the trend of ever-increasing payload mass a long time, it was equipped with a flexible concept of boosters. This should enable her to during their period perform cost-saving double -offs. On one hand, the solid rocket boosters of Ariane 3 were highly stretched to increase their performance, on the other hand, three new liquid-propellant boosters were from the second stage of the Ariane derived, which were significantly larger and heavier than the extended solid propellant booster and had a better performance than this. Moreover, the first step towards the Ariane 3 was highly stretched to accommodate significantly more fuel can. Thus, the tank capacity was so great that the first step could only be fully fueled when it was started with at least four solid boosters, otherwise the engine power was not sufficient to allow the heavy lift rocket. This meant that in versions in which the first stage could not be refueled, the burning time was shorter than normal because the engines had the fuel supply consumed in less time. The second and third stages is not changed in the development of Ariane Ariane 4 relative to the 3. For this, a new fairing with 4 m diameter and an equally wide double starter was introduced. Order in addition to the large satellite also be able to take still small when payload capacity was still free, the ASAP -4 device ( Ariane Structure for Auxiliary Payloads ) was available. She allowed the carrying of several to 60 kg satellite that could be 60 cm high and 45 cm wide and long. The satellites were together weigh 240 kg.

During the production time of the Ariane 4, the satellite masses went beyond what was originally planned for Ariane 4 level continues to rise, the Ariane 4 underwent several modifications to improve performance. Besides the introduction of lighter materials for cladding, compressed gas tanks, etc. However, these were almost exclusively related to the third stage. The third stage ( H 10 ) was first extended in 1992 to accommodate more fuel can (H 10 ). As this was not enough, the fuel mix in 1994 was converted to a higher oxygen content and thus increasing the payload capacity again ( H 10 III).

As the successor to Ariane 5 was delayed and the Ariane 4, also three more times after false starts / partial success of this had to jump into the breach, it was produced as originally planned in much larger quantities and longer. However, it was during this time, no programs to improve performance more. Therefore, in the end, almost all satellites so heavy that even the most powerful Ariane - 4 version ( Ariane 44L ) mostly only able to perform single starts.

Versions

For different heavy payloads were six missile configurations. At the pure series -stage rocket ( called Ariane 40) could be attached to the payload increase either side solid and / or liquid-propellant boosters. Following Ariane -4 versions were available:

  • 40 - without booster
  • 42L - two liquid-propellant boosters
  • 42P - two solid boosters
  • 44L - four liquid-propellant boosters
  • 44P - four solid boosters
  • 44LP - two liquid-propellant booster and two solid boosters

Syntax: The first number stands for Ariane 4, the second for the number of boosters and the letters for the Fuel - L = liquid (French ) = liquid, P = poudre (French ) = fixed.

During the approximately 15 years of using numerous improvements have been made to the rocket to increase their payload. The main attention was paid to the increase in the last stage performance. The first flights sat still the H10 adopted by the Ariane 2/3. After the tanks were extended by 32 cm, so 400 kg more fuel could be delivered to load. This stage, H-10 Plus, flew 27 times. From flight V70 - the 32nd Start - came another version of the advanced level for use, at which the mixture was rich in oxygen by shifting the intermediate floor. This H-10 III -called upper was used until the end. So the Treibstoffzuladung increases from 10.7 to 11.9 tonnes and with lighter materials in the VEB, the maximum payload of 4,330 to 4950 kg.

Coated version

There were plans for an Ariane 43P with three PAP solid boosters. The version, however, was not realized.

Ariane -4- version data

Notes:

Technical data of the rocket stages used

  • The H10- III third stage was only used from the end of 1994, before the weaker H10 and H10 third stages were in use.

Swell

Starts

All Ariane 4 rocket took off in French Guiana launch site from the ELA -2 of the Guiana Space Centre. The launch pad ELA -2 consisted of:

  • An assembly building where the missiles were mounted up on the solid rocket boosters and the payload,
  • A rail track on which the were driven to one of two portable launchers mounted rockets to the launch pad with launch tower,
  • A mobile gantry.

After the rocket had reached the launch site, the gantry was over they went and put the already assembled to form a unit payload fairing and dual starter with the satellites within them to the rocket. Here the solid rocket boosters attached - also were - if provided. The second stage has also been fueled in the gantry and is provided with an insulation ( the oxidizer would evaporate at more than 21 ° C). Thereafter, the mobile assembly tower is driven to one side, filled up the first and third stage of the rocket and then the rocket is launched, whereby the insulating material of the second stage decreases.

de