Das Nauka-Modul für die Internationale Raumstation, gestern mit 12-jähriger Verspätung von Baikonur zur ISS gestartet, scheint in ernsthaften Schwierigkeiten zu sein. Die Berichte sind widersprüchlich, aber anscheinend sind sowohl das Haupttriebwerk für die achttägige Annährung an die Station als auch (vielleicht) die Steuerdüsen für den Feinschliff nicht einsatzfähig. Als Ursache werden z.Zt. zwei Möglichkeiten gehandelt: Korruption der Zuleitungen durch jahrelangen Eintrag von Metallstaub, oder Verwechslung der Zuleitungen, die unter unterschiedlicehm Druck stehen (8 und 45 bar respektive). Die russische Bodenkontrolle scheint zuversichtlich, daß sich das ausbügeln läßt.
Die gegenwärtige Umlaufbahn der Нау́ка ist für rund 30 Erdumkreisungen stabil.
The delayed firrst orbit raise burn for Nauka will now take place in the next few hours using backup engines, as the main engines are at least temporarily out of action. Here are the apogee and perigee orbital heights for Nauka (blue) and the rocket stage (red) so far
Zitat Katya Pavlushchenko @katlinegrey The undocking of #Pirs is scheduled for July 26, 10:56 UTC. The engine deorbit burn will be performed at 14:01 UTC. #ProgressMS16 "Gerasim" with the Pirs module will burn up over the Pacific Ocean at 14:51 UTC. 4:57 nachm. · 25. Juli 2021·Twitter Web App
Mit beständiger Zuleitung von Edelmetall lassen sich alle Administrationen zuverlässig korrumpieren.
Gemeint war das hier:
Zitat In August 2018, Roscosmos head Dmitry Rogozin set a new launch date of November 2019. However, the propellant tanks were found to be contaminated with metallic dust in 2017, requiring repair and replacement work; a tentative new launch date in June 2020 was set, but not met due to the repair of the fuel tanks being initially unsuccessful; NPO Lavochkin was slated to produce new single-use fuel tanks based on the Fregat upper stage. Production of this new fuel system, installation into Nauka (at NPO Energia), and additional testing delayed the launch to sometime after 2020.
___________________ Jeder, der Merkel stützt, schützt oder wählt, macht sich mitschuldig. “Die gefährlichsten Unwahrheiten sind Wahrheiten mäßig entstellt”, Georg Cristof Lichtenberg "Warum halten sie Begriffe wie 'Zigeunersoße' für rassistisch, aber 'Schei** Juden' für harmlos?", Hamed Abdel-Samad
Zitat Chris G - NSF @ChrisG_NSF NASA TV, Rob Navias, updating the situation now. - Zvezda's hatch was opened and crew was in process of getting things up and running when at 12:45pm EDT, Nauka began firing uncontrolled. ISS 45 degrees out of attitude. NO DANGER TO CREW! 1/x 7:32 nachm. · 29. Juli 2021·Twitter Web App
Chris G - NSF @ChrisG_NSF Progress thrusters were used to regain ISS nominal attitude. Station is in a good configuration now. Russia teams will working Nauka thruster issue. 2/x 7:33 nachm. · 29. Juli 2021·Twitter Web App
Zitat Anatoly Zak @RussianSpaceWeb #ISS crew reports some flashes on #ISS from newly arrived #Nauka module, indicating some inadvertent thrusters firings (or propellant leaks)... The crew is advised to close windows... 6:51 nachm. · 29. Juli 2021·Twitter Web App
Zitat Anatoly Zak @RussianSpaceWeb Some good news: #Nauka module burned ALL the propellant available to its thrusters during its brawl after docking with #ISS, so there no chance it could happen again. DETAILS: http://russianspaceweb.com/insider-content.html 9:35 nachm. · 29. Juli 2021·Twitter Web App
Zitat High drama as Russian lab module tilts space station with errant thruster firings
A heavyweight Russian laboratory module that experienced a variety of problems after launch last week docked at the International Space Station Thursday, but in a moment of unexpected drama, inadvertent thruster firings briefly knocked the sprawling complex out of its normal orientation.
Space station program manager Joel Montalbano said the station was maintaining its orientation, or “attitude,” using massive NASA-supplied gyroscopes when the thruster firings suddenly began at 12:34 p.m. EDT, about three hours after the 44,000-pound Nauka multi-purpose laboratory glided in for docking.
The gyros were unable to counteract the unwanted push from Nauka’s jets and the space station, stretching the length of a football field with a mass of more than 930,000 pounds, began tilting away from its normal orientation.
Attitude control was quickly handed off to more effective rocket motors in the Russian Zvezda module, where Nauka was attached. A few minutes later, thrusters in a Progress cargo ship docked on the other side of Zvezda kicked in with additional muscle.
The space station ended up tilted up about 45 degrees from its earlier orientation, moving at one point at roughly half a degree per second. But in a little more than an hour, the station was back in its normal orientation, apparently none the worse for wear.
“We haven’t noticed any damage to the ISS,” Montalbano said in an afternoon teleconference. “One of the things we do after a dynamic event like this is go ahead and sit down with our structural loads team and review all the data, go pull all the telemetry and do an assessment. And so that’ll be the next step.”
Zitat von Aug. 6, 2021In an International Space Station major milestone more than fifteen years in the making, a long-delayed Russian science laboratory named Nauka automatically docked to the station on 29 July, prompting sighs of relief in the Mission Control Centers in Houston and Moscow. But within a few hours, it became shockingly obvious the celebrations were premature, and the ISS was coming closer to disaster than at anytime in its nearly 25 years in orbit. While the proximate cause of the incident is still being unravelled, there are worrisome signs that NASA may be repeating some of the lapses that lead to the loss of the Challenger and Columbia space shuttles and their crews. ... In a cyber-logical process still not entirely clear, while passing northwest to southeast over Indonesia, the Nauka module's autopilot apparently decided it was supposed to fly away from the station. Although actually attached, and with the latches on the station side closed, the module began trying to line itself up in preparation to fire its main engines using an attitude adjustment thruster. As the thruster fired, the entire station was slowly dragged askew as well.
Since the ISS was well beyond the coverage of Russian ground stations, and since the world-wide Soviet-era fleet of tracking ships and world-circling network of "Luch" relay comsats had long since been scrapped, and replacements were slow in coming, nobody even knew Nauka was firing its thruster, until a slight but growing shift in the ISS's orientation was finally detected by NASA.
Within minutes, the Flight Director in Houston declared a "spacecraft emergency"—the first in the station's lifetime—and his team tried to figure out what could be done to avoid the ISS spinning up so fast that structural damage could result. The football-field-sized array of pressurized modules, support girders, solar arrays, radiator panels, robotic arms, and other mechanisms was designed to operate in a weightless environment. But it was also built to handle stresses both from directional thrusting (used to boost the altitude periodically) and rotational torques (usually to maintain a horizon-level orientation, or to turn to a specific different orientation to facilitate arrival or departure of visiting vehicles). The juncture latches that held the ISS's module together had been sized to accommodate these forces with a comfortable safety margin, but a maneuver of this scale had never been expected.
Meanwhile, the station's automated attitude control system had also noted the deviation and began firing other thrusters to countermand it. These too were on the Russian half of the station. The only US orientation-control system is a set of spinning flywheels that gently turn the structure without the need for thruster propellant, but which would have been unable to cope with the unrelenting push of Nauka's thruster. Later mass-media scenarios depicted teams of specialists manually directing on-board systems into action, but the exact actions taken in response still remain unclear—and probably were mostly if not entirely automatic. The drama continued as the station crossed the Pacific, then South America and the mid-Atlantic, finally entering Russian radio contact over central Europe an hour after the crisis had begun. By then the thrusting had stopped, probably when the guilty thruster exhausted its fuel supply. The sane half of the Russian segment then restored the desired station orientation.
Initial private attempts to use telemetry data to visually represent the station's tumble that were posted online looked bizarre, with enormous rapid gyrations in different directions. Mercifully, the truth of the situation is that the ISS went through a simple long-axis spin of one and a half full turns, and then a half turn back to the starting alignment. The jumps and zig-zags were computational artifacts of the representational schemes used by NASA, which relate to the concept of "gimbal lock" in gyroscopes.
How close the station had come to disaster is an open question, and the flight director humorously alluded to it in a later tweet that he'd never been so happy as when he saw on external TV cameras that the solar arrays and radiators were still standing straight in place. And any excessive bending stress along docking interfaces between the Russian and American segments would have demanded quick leak checks. But even if the rotation was "simple," the undeniably dramatic event has both short term and long-term significance for the future of the space station. And it has antecedents dating back to the very birth of the ISS in 1997.
The bureaucratic instinct to minimize the described potential severity of the event needs cold-blooded assessment. Sadly, from past experience, this mindset of complacency and hoping for the best is the result of natural human mental drift that comes when there are long periods of apparent normalcy.
Der entscheidende Passus:
Zitat As far as Nauka's role in this process of safety-culture repair, it turns out that quite by bizarre coincidence, a similar pattern was played out by the very first Russian launch that inaugurated the ISS program, the 'Zarya' module [called the 'FGB'] in late 1997. Nauka turns out to be the repeatedly rebuilt and upgraded backup module for that very launch, and the parallels are remarkable. The day the FGB was launched, on 23 November 1997, the mission faced disaster when it refused to accept ground commands to raise its original atmosphere-skimming parking orbit. As it crossed over Russian ground sites, controllers in Moscow sent commands, and the spacecraft didn't answer. Meanwhile, NASA guests at a nearby facility were celebrating with Russian colleagues as nobody told them of the crisis. Finally, on the last available in-range pass, controllers tried a new command format that the onboard computer did recognize and acknowledge. The mission—and the entire ISS project—was saved, and the American side never knew. Only years later did the story appear in Russian newspapers.
Bitte beachten Sie diese Forumsregeln: Beiträge, die persönliche Angriffe gegen andere Poster, Unhöflichkeiten oder vulgäre Ausdrücke enthalten, sind nicht erlaubt; ebensowenig Beiträge mit rassistischem, fremdenfeindlichem oder obszönem Inhalt und Äußerungen gegen den demokratischen Rechtsstaat sowie Beiträge, die gegen gesetzliche Bestimmungen verstoßen. Hierzu gehört auch das Verbot von Vollzitaten, wie es durch die aktuelle Rechtsprechung festgelegt ist. Erlaubt ist lediglich das Zitieren weniger Sätze oder kurzer Absätze aus einem durch Copyright geschützten Dokument; und dies nur dann, wenn diese Zitate in einen argumentativen Kontext eingebunden sind. Bilder und Texte dürfen nur hochgeladen werden, wenn sie copyrightfrei sind oder das Copyright bei dem Mitglied liegt, das sie hochlädt. Bitte geben Sie das bei dem hochgeladenen Bild oder Text an. Links können zu einzelnen Artikeln, Abbildungen oder Beiträgen gesetzt werden, aber nicht zur Homepage von Foren, Zeitschriften usw. Bei einem Verstoß wird der betreffende Beitrag gelöscht oder redigiert. Bei einem massiven oder bei wiederholtem Verstoß endet die Mitgliedschaft. Eigene Beiträge dürfen nachträglich in Bezug auf Tippfehler oder stilistisch überarbeitet, aber nicht in ihrer Substanz verändert oder gelöscht werden. Nachträgliche Zusätze, die über derartige orthographische oder stilistische Korrekturen hinausgehen, müssen durch "Edit", "Nachtrag" o.ä. gekennzeichnet werden. Ferner gehört das Einverständnis mit der hier dargelegten Datenschutzerklärung zu den Forumsregeln.