Featured Research

from universities, journals, and other organizations

Ariane 5 Places Two Satellites In Orbit, Shows Promise For ATV Jules Verne

Date:
October 24, 2007
Source:
European Space Agency
Summary:
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.

Ariane 5 V178 lift off.
Credit: ESA - CNES - Arianespace / Photo Optique Video CSG

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 Ariane5ES 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 5October - when an Ariane5GS 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 - 54minutes 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 Ariane5 upper stage to fire only once. A few seconds after the Ariane5 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 250km and an apogee of 36000km. Once injected into this transfer orbit, the satellites use an apogee boost motor to raise the orbit perigee to 36000km 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 36000km.

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 8minutes to reach an elliptical orbit (136km x 260km). Then, after a coasting phase to the apogee of the elliptical orbit lasting 48minutes, a second boost with a duration of 30 seconds serves to reach the ATV circular injection orbit at an altitude of 260km.

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.


Story Source:

The above story is based on materials provided by European Space Agency. Note: Materials may be edited for content and length.


Cite This Page:

European Space Agency. "Ariane 5 Places Two Satellites In Orbit, Shows Promise For ATV Jules Verne." ScienceDaily. ScienceDaily, 24 October 2007. <www.sciencedaily.com/releases/2007/10/071022120157.htm>.
European Space Agency. (2007, October 24). Ariane 5 Places Two Satellites In Orbit, Shows Promise For ATV Jules Verne. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2007/10/071022120157.htm
European Space Agency. "Ariane 5 Places Two Satellites In Orbit, Shows Promise For ATV Jules Verne." ScienceDaily. www.sciencedaily.com/releases/2007/10/071022120157.htm (accessed July 25, 2014).

Share This




More Space & Time News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: ISS Cargo Ship Launches in Kazakhstan

Raw: ISS Cargo Ship Launches in Kazakhstan

AP (July 23, 2014) The Progress 56 cargo ship launched from the Baikonur Cosmodrome in Kazakhstan Wednesday. NASA says it will deliver cargo and crew supplies to the International Space Station. (July 23) Video provided by AP
Powered by NewsLook.com
Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com
Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins