Автор Александр Репной, 16.02.2012 18:40:27
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ЦитатаWe have been asked to use ATV-5 to decrease - a little - the ISS altitude, by around 1 km.A lower orbit slightly increases the (already tiny) drag exerted by the wisps of atmosphere on the ISS and, therefore, also increases the decay of the ISS orbit. This allows the visiting vehicles (Progress, SpaceX, Cygnus, &etc.) to bring up to Station a heavier load.ATV-5 will be used this afternoon to 'put on the brakes', reducing the speed of the ISS so that it consequently will drop to new lower, but stable, orbit.The boost (in this case, 'deboost') has a value of 0.68 m/s and is planned to run between 18:40:00 to 18:44:49 UTC (19:40:00-19:44:49 CET.It is the first time that an ATV has been used to decrease the altitude; usually, on the contrary, ATV propulsive support is used to lift the orbit due to the regular decay (around 1 or 2 km per month). To allow this manoeuvre, the ISS has been turned 180 degrees so that the ATV, docked to the rear, is in front of the other modules with its thrusters directed opposite to the Station's velocity vector.
ЦитатаATV-56 February 2015Next Monday, ESA astronaut Samantha Christoforetti will float into Europe's space ferry to install a special infrared camera, set to capture unique interior views of the spacecraft's break-up on reentry."The battery-powered camera will be trained on the Automated Transfer Vehicle's forward hatch, and will record the shifting temperatures of the scene before it," explains Neil Murray, overseeing the project for ESA."Recording at 10 frames per second, it should show us the last 10 seconds or so of the ATV. We don't know exactly what we might see - might there be gradual deformations appearing as the spacecraft comes under strain, or will everything come apart extremely quickly?"Our Break-Up Camera, or BUC, flying for the first time on this mission, will complement NASA's Reentry Break-up Recorder.BUC Infrared Camera and SatCom"Whatever results we get back will be shared by our teams, and should tell us a lot about the eventual reentry of the International Space Station as well as spacecraft reentry in general."Every mission of ESA's ATV ferry ends in the same way - filled with Space Station rubbish then burning up in the atmosphere, aiming at a designated 'spacecraft graveyard' in an empty stretch of the South Pacific.But the reentry of this fifth and final ATV is something special. NASA and ESA are treating it as an opportunity to gather detailed information that will help future spacecraft reentries.Camera calibration targetsAccordingly, ATV-5 will be steered into a shallow descent compared to the standard deorbit path.This ATV's fiery demise will be tracked with a battery of cameras and imagers, on the ground, in the air and even fr om the Station itself, and this time on the vehicle itself.ESA's camera will not survive the reentry, expected to occur some 80-70 km up, but it is linked to the 'SatCom' sphere with a ceramic thermal protection system to endure the searing 1500°C.Artist's view of ATV-5 reentryOnce SatCom is falling free, it will transmit its stored data to any Iridium communication satellites in view.Plunging through the top of the atmosphere at around 7 km/s, it will itself be surrounded by scorching plasma known to block radio signals, but the hope is that its omnidirectional antenna will be able to exploit a gap in its trail.If not, signalling will continue after the plasma has cleared - somewh ere below 40 km altitude.Japan's i-Ball camera managed to gather images of its Station supply ferry breaking up in 2012. Another i-Ball was planned to fly with ATV-5, but was lost in the Antares rocket explosion last October.ATV cutawayESA's camera team had to develop flight-ready hardware in just nine months. The camera and capsule was constructed by Ruag in Switzerland, with thermal protection contributed by the DLR German Aerospace Center, Switzerland's ETH Zurich contributing software, Switzerland's Viasat responsible for antenna and electronics and Denmark's GomSpace delivering batteries."Between us and the NASA side, there are a lot of fingers crossed at the moment," Neil adds."For the future, now the development has already been done, the camera has broader potential as a 'blackbox for reentry', flyable on a wide range of satellites and launchers."The camera will be activated by a set sequence of acceleration by ATV. Some 10 seconds' worth of 320x256 frames from the camera will be buffered in the SatCom memory at a time plus about one-frame-per-second reference images of the previous set, and progressively overwritten as fresh imagery arrives.
Цитатаanik пишет: Планы поменялись - сведение с орбиты будет 15 февраля вместо 27 февраля и никакого шоу не будет: http://blogs.esa.int/atv/2015/02/10/atvs-not-over-til-its-over/
ЦитатаReader пишет: P.S. Не могу почитать исходник
ЦитатаESA Operations @esaoperations 14m ago#atv5 hatch is closed
ЦитатаESA Operations @esaoperations 1m agoSEPARATION #ATV5
ЦитатаESA @esa 1m agoSeparation of final ATV confirmed at 14:42 CET RT @esaoperations: SEPARATION #ATV5
ЦитатаESA Operations @esaoperations 7m agoATV-CC confirms: the first #ATV5 deorbit boost ran exactly as planned. It delivered a change in speed of 51.7 m/second
Цитата@esaoperations 28 минут назадMain screen at #ATV5 control centre showing the spacecraft's altitude top right #BigDive http://blogs.esa.int/atv/2015/02/15/first-deorbit-burn-successful/ ...
ЦитатаDeorbit burns today will pitch Georges into safe reentry Posted on 15 Feb 2015 by Daniel The joint ESA & CNES team at ATV Control Centre in Toulouse have been monitoring ATV-5 continuously since yesterday's undocking at 14:40 CET. The major timeline events today are the two deorbit burns, set as follows: DEO1 14:29:29 GMT delta-v 51.7 m/s duration 826 seconds DEO2 17:26:01 GmT delta-v 89.6 m/s duration 1398 secondsAfter DEO2 ends at 17:49:18 GMT, the ATV thrusters will be briefly fired to start the craft tumbling, so as to ensure that the atmosphere 'grabs' Georges and starts to drag it down to safe reentry. It will enter the atmosphere at about 100km altitude over the Pacific, Impact is expected at 18:12 GMT; some minutes before this, LOS (loss of signal) will have occurred.
Цитата@esaoperations 2 мин.In just a few minutes, the last-ever ATV will begin its final orbit - its last tour above our blue Earth #ATV5
ЦитатаATV Georges Lemaître has been sent towards Earth for its controlled reentry after completing its second and last deorbit burn.The 23.3-minute burn reduced the spacecraft's speed by 322.56 km/h and set it heading for its fiery end.Imagine sending the command to destroy the spacecraft that you have worked on and with for many years. Emotional moments for the teams at the ATV Control Centre in Toulouse, France.The final command will be sent to the spacecraft at 18:06 GMT setting Georges Lemaître to tumble and rotate to improve its drag.
ЦитатаESA Operations @esaoperations 9m agoLOSS OF SIGNAL #LOS Contact with #ATV5 Georges Lemaître lost, as expected. It's all over #BigDive
ЦитатаNilk пишет: не понимаю зачем такое расточительство.
ЦитатаSOE пишет: придумать, кто бы это оплачивал