Astronautique : actualités / news

Le lancement de la fusée Ariane 5-ES, qui doit mettre sur orbite le véhicule de transfert automatique "Johannes Kepler" appelé à s'arrimer à la Station spatiale internationale, a été reporté mardi en raison d'un problème technique.

La fusée Ariane 5-ES n'a pas décollé mardi soir en raison d'un problème technique. Le lancement est désormais programmé mercredi à 18h50 heure locale (21h50 GMT). Ariane, dont ce sera la 200e mission, devait décoller à 19h13 (22h13 GMT) mardi du centre spatial de Kourou, en Guyane, mais le compte à rebours a été interrompu quelques instants auparavant.

Quatre minutes et une seconde avant le lancement, un voyant rouge "ensemble de lancement" s'est allumé. Un capteur a indiqué un niveau trop élevé d'oxygène liquide dans un réservoir. "On avait un peu trop d'oxygène", a déclaré à la presse Jean-Yves Le Gall, le patron d'Arianespace. "Le capteur a arrêté la chronologie. Cela interdit de faire une autre tentative ce soir puisque nous devions partir exactement à 19h13", a-t-il ajouté. Le décollage est prévu à un instant précis afin de mettre son passager, le Véhicule de Transfert Automatique (ATV) "Johannes Kepler" sur une orbite circulaire.

"Quand on n'a qu'une seconde pour lancer, c'est complètement différent (par rapport à une fenêtre de tir) et c'est plus risqué", a pour sa part commenté la ministre de la Recherche et de l'Enseignement Supérieur, Valérie Pécresse. L'ATV doit passer en vol autonome à une altitude de 260 kilomètres grâce à quatre grands panneaux solaires et des batteries. Il doit ensuite s'amarrer quelques jours plus tard à la Station spatiale internationale (ISS). Comme son prédécesseur, l'ATV-1 "Jules Verne", "JohannesKepler" doit assurer le ravitaillement de l'ISS en vivres et rehausser l'orbite de la station. Pesant plus de 20 tonnes, l'ATV-2 représente la plus importante charge utile à ce jour pour une Ariane-5. Cette première mission de 2011 constitue la 200e depuis le vol inaugural d'Ariane.

http://lci.tf1.fr/science/nouvelles-technologies/le-lancement-d-ariane-5-reporte-6279482.html

Russia’s Progress 44 supply capsule, filled with 5,900 lb. of supplies for the International Space Station, crashed back to Earth shortly after launching aboard a Soyuz rocket early Aug. 24, injecting uncertainty over future cargo and crew transport plans early in NASA’s post-shuttle era.

The unpiloted space freighter commanded a shutdown of the third stage in response to an engine anomaly 325 sec. after lifting off from the Baikonur Cosmodrome in Kazakhstan at 9 a.m. EDT, or 7 p.m. local time. The third stage with the Progress plummeted into the Altai region of the Russian republic.

NASA’s STS-135 flight, a station re-supply mission that marked the end of NASA’s 30-year shuttle program as it touched down on July 21, left the orbiting research lab fortified with supplies at least through March. However, the Soyuz-U variant that initiated the failed Progress mission has hardware similarities with the Soyuz-FG version, the only rocket available to transport astronauts to the space station in the shuttle’s absence, says NASA’s Mike Suffredini, International Space Station program manager.

“Obviously, this has implications for the vehicle on orbit and the crew,” Suffredini told a Johnson Space Center news briefing.

NASA expects to participate in the Russian investigation of the Soyuz failure, though the format for a formal inquiry was still being addressed, he said.

The U.S. crew transportation services that NASA is nurturing under the Commercial Drew Development initiative are not forecast to begin operations until 2015-16.

In the near term, the Aug. 24 failure could delay plans to return the Expedition 28 crew of Andrey Borisenko, Alexander Samokutyaev and Ron Garan to Earth aboard the Soyuz TMA-21 on Sept. 7, after 156 days in orbit. Prior to the loss, they were scheduled to be replaced by the launch of two Russians and an American aboard the Soyuz TMA-03M on Sept. 21, restoring the orbital base to the desired six-person crew operations.

Borisenko, Samokutyaev and Garan crew could remain in orbit for an additional one to two months, Suffredini says. Mission managers would prefer to time the launching of a Soyuz replacement crew until after a successful Progress flight and about two weeks before the Expedition 28 veterans return to Earth, Suffredini says.

Progress 45 and 46 launches had been tentatively scheduled for late October and late December. However, a long-running investigation and recovery from the Progress 44 loss could force the U.S-led, 15-nation space station partnership to cut the crew size to three astronauts. A reduction in the crew would greatly impact the surge in scientific station research and technology demonstrations anticipated as the near 13-year assembly and outfitting of the station came to a close with the final shuttle flight.

NASA’s STS-135 mission in July aboard Atlantis delivered a year’s worth of supplies to the station to bridge the gap between the shuttle’s final mission and the start of U.S. commercial re-supply missions.

SpaceX, one of two emerging providers, is aiming for the Nov. 30 launch of an ambitious demonstration mission that would attempt the first space station berthing by a U.S. commercial supplier.

However, with the possible exception of some spare parts for the station’s toilet, the Atlantis flight provided enough food and other supplies to sustain six astronauts through 2012 without deliveries from SpaceX or the Orbital Sciences, the second commercial supplier, Suffredini says.

The Progress 44 was to dock with the station on Aug. 26, filling the Russian segment aft docking port vacated by the Progress 43 on Aug. 23. The new freighter was to serve as the propulsion source for orbital adjustments and orbital debris avoidance maneuvers by the more than 900,000-lb. orbital outpost.

Europe’s Automated Transfer Vehicle II boosted the station to record altitudes before its departure in June, easing some of the re-boost requirements. The orbiting lab, circling the Earth at a mean altitude of 240 mi. before the Progress loss, can rely on Russian segment thrusters in the Zvezda service module for maneuvers.

HOUSTON — Appearing before a House oversight panel this week, NASA’s chief human spaceflight official and two of the agency’s independent safety experts endorsed Russian efforts to investigate and recover from the Aug. 24 loss of a Soyuz rocket without forcing an evacuation of the six-person International Space Station.

The loss of the Soyuz-U booster carrying a Progress cargo capsule revealed the pitfall of a decision by U.S. policy makers to retire the space shuttle in July — at least four to five years before NASA-nurtured commercial crew capabilities are expected to be ready to take on the role of transporting astronauts to and from the orbiting science laboratory.

Russia responded quickly, identifying a contaminant blockage in a third-stage fuel line or stabilizer valve as the root cause and implementing a recovery strategy, according to Bill Gerstenmaier, NASA’s associate administrator for human exploration and operations.

“NASA is confident that our Russian partners identified the most likely failure cause and a sound return-to-flight plan,” Gerstenmaier told the House Space and Aeronautics Subcommittee on Oct. 12 in Washington.

The Russian response received a similar vote of confidence from Thomas Stafford, the retired U.S. Air Force lieutenant general and Apollo-era astronaut who chairs NASA’s International Space Station Advisory Committee, and Joseph Dyer, the retired U.S. Navy vice admiral who chairs the agency’s Aerospace Safety Advisory Panel (ASAP).

U.S. Rep. Steven Palazzo (R-Miss.), the committee chairman, and other lawmakers raised a series of issues, including Russia’s diligence in identifying the root cause of the loss to the prospects of returning the retired shuttle fleet to flight.

“This would have been a great research question three or perhaps four years ago,” Dyer said of a shuttle encore. “But it’s not a good question, or a practical question, at this time.”

The Russian commission that investigated the loss concluded the contamination was most likely introduced during an inspection that followed a hot-fire acceptance test of the engine, Gerstenmaier told the panel. Once in flight, the blockage reduced the fuel flow to the RD-0110 engine just more than 300 sec. into the flight from the Baikonur Cosmodrome. The reduction triggered a computer shutdown of the engine that sent the Progress plummeting into a mountainous region of Altai.

Similarities

The Soyuz-U shares a similar third stage to the Soyuz-FG used to transport three-person crews to and from the space station.

The investigation included a factory recall of 18 upper-stage Soyuz engines for reinspection. Further contamination was not found, supporting the conclusion that the failure was not caused by a design flaw.

Additional quality control inspectors have been added to the RD-0110 production line along with video documentation of the assembly processes, according to Gerstenmaier, who was briefed on the findings by Russian officials. The human exploration chief charged a NASA team with assessing the Russian conclusion. It agreed with the assessment.

As part of the recovery, Russia agreed to a pair of unmanned Soyuz missions ahead of the next crew launch. The first of the “test flights” occurred successfully on Oct. 2 with the launching of a Soyuz-2 rocket with a Glonass-M navigation satellite from Plesetsk.

The second flight will be an Oct. 30 launch of a Soyuz-U from Baikonur to the space station with the Progress 45 freighter. If the Soyuz-U launch is a success, Russia will prepare the Soyuz 28 mission for launch with an American and two Russians to the space station on Nov. 14.

• Nouveau record pour Ariane 5 qui vient d’emporter 10,317 tonnes en orbite géostationnaire
• Le vol Ariane 212 est le 54ème succès consécutif du lanceur européen Ariane 5, dont Astrium est maître d’œuvre depuis 2003
• C’est le premier tir réussi pour Ariane 5 en 2013 Le 7 février 2013 - Ariane 5 vient d’être lancée avec succès depuis Kourou en Guyane française pour la 54^ème
fois consécutive, confirmant une fois encore l’extraordinaire fiabilité
du lanceur européen développé et construit par Astrium, numéro un
européen de l’industrie spatiale.

Pour ce 212^ème vol Ariane, la performance requise était de 10,317 tonnes en orbite géostationnaire
dont 9,503 tonnes pour les deux satellites, un nouveau record. Le reste
correspond au SYLDA, le système de lancement double d’Astrium, et aux
structures adaptatrices pour les satellites.

La version d’Ariane 5 utilisée pour ce lancement, appelée « ECA »,
permet de placer deux charges utiles en orbite avec un seul lanceur,
minimisant de fait les coûts d’exploitation. Un programme d’amélioration
constante conduit par Astrium avec l’Agence spatiale européenne (ESA)
permet, tout en poursuivant les efforts de réduction des coûts,
d’augmenter les performances du lanceur, offrant régulièrement à Ariane 5
des records de masse placée en orbite géostationnaire, comme
aujourd’hui avec plus de 10,3 tonnes.

Astrium est le maître d’œuvre du lanceur européen Ariane 5 depuis
2003. A ce titre, l’entreprise coordonne une chaîne industrielle
regroupant plus de 550 entreprises (dont plus de 20% de PME) dans douze
pays européen. Grâce à l’expertise développée et aux investissements mis
en œuvre par la société depuis près de 10 ans, Ariane 5 est devenu le
lanceur le plus fiable du marché mondial et a pu augmenter sa capacité
d’emport de près d’une tonne en orbite géostationnaire