Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Successful Ariane 5 upper stage engine re-ignition experiment

23.10.2007
A successful re-ignition of the Ariane 5 upper stage engine performed during the most recent mission has consolidated Ariane 5's readiness for the launch of the Jules Verne Automated Transfer Vehicle.

The launch of ESA's Automated Transfer Vehicle (ATV), which carries supplies to the International Space Station, will require multiple firings of the Ariane 5 ES upper stage engine. In this context, hundreds of re-ignition tests under various thermal conditions have been undertaken at the DLR Test Centre in Lampoldshausen to qualify the Aestus engine for several re-ignitions.

In order to consolidate this on ground qualification a re-ignition experiment was performed during the last Ariane-5 launch - on the evening of 5 October - when an Ariane 5 GS launcher lifted off from Europe's Spaceport in French Guiana carrying two commercial telecommunications satellites into geostationary transfer orbit.

Once the commercial payloads were safely on their way, a successful experimental re-ignition of the Aestus engine took place - 54 minutes after the release of the second payload. The experiment was done to validate operational conditions (mainly temperatures and pressures) and procedures (propellant settling in tanks) of the launcher upper stage, which will be applied during the ATV orbital injection mission. It also verified the behaviour of the composite during the re-ignition phase.

Analysis of the many temperature and pressure parameters is ongoing and confirms a nominal behaviour very close to expectations. “We are extremely satisfied with the results of the Aestus re-ignition experiment, which confirms the on ground qualification of the re-ignition capability and adds to our confidence of mission success for the launch of ATV Jules Verne in the early part of next year” said ESA's Ariane Programme Manager, Toni Tolker-Nielsen.

Launch to geostationary transfer orbit

A communications satellite launch requires the engine on the Ariane 5 upper stage to fire only once. A few seconds after the Ariane 5 main stage separates, the upper stage engine ignites to continue propelling the upper stage and payloads towards geostationary transfer orbit. The engine is shut down once the correct orbit for the injection of the payloads into their transfer orbits has been reached.

The standard geostationary transfer orbits for communications satellites are elliptical, with a perigee of 250 km and an apogee of 36 000 km. Once injected into this transfer orbit, the satellites use an apogee boost motor to raise the orbit perigee to 36 000 km by firing the motor when the satellites are at the apogee of the transfer orbit. This staged approach is the optimum from an energetic point of view and allows the placing of the highest mass into a circular geostationary orbit at an altitude of 36 000 km.

Automated Transfer Vehicle launch

Launching the ATV will be more complex because the target orbit is circular, rather than elliptical.

After main stage separation over the Atlantic Ocean, the Aestus engine of the upper stage will perform a first boost lasting 8 minutes to reach an elliptical orbit (136 km x 260 km). Then, after a coasting phase to the apogee of the elliptical orbit lasting 48 minutes, a second boost with a duration of 30 seconds serves to reach the ATV circular injection orbit at an altitude of 260 km.

This second firing of the Aestus engine will take place over southeast Australia, just over an hour into the flight. Four minutes later, the ATV will separate over the Pacific, ready to fly to the International Space Station using its own navigation and propulsion systems.

One orbit later, now over Western Australia, the Aestus engine will re-ignite briefly, for a third time, causing the launcher's upper stage to de-orbit safely and burn up during a precise destructive re-entry over of the South Pacific Ocean.

Toni Tolker-Nielsen | alfa
Further information:
http://www.esa.int/SPECIALS/Launchers_Home/SEM1X03Z28F_0.html

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>